# TurbulentDissipation unstable with a local scour around a pier simulattion

dear all,
i've try to simulate a local scour around a pier with sediment model build in FLUIDITY.

subgridscale parameterisations/kepsilon is be used and kepsilon boundary is be applied to bottom and pier sides.but the "TurbulentDissipation" around the pier surface would increase greatly with time.

I've try to turn off sediment model, or modify the grid resolution and background viscosity but still
can't let "TurbulentDissipation" stable.

any comment is appreciated. thanks.

# box set
Length:0.36 m
Width:0.36 m
Height:0.07 m

# velocity boundary
west : a constant velocity 0.2 m/s (inlet)
east : zero-gradient boundary conditions (outlet)
south and north : free slide wall
top : free surface
bottom : no normal flow and drag
pier : no normal flow

the geo and flml content is attached below.

# --- pier_scour.geo ---
d1=0.03; //0.03
d3=0.01; //0.01
len=0.36; //0.36
wid=0.36; //0.36
Point(1) = {-0.5*len, -0.5*wid, 0, d1};
Point(2) = { 0.5*len, -0.5*wid, 0, d1};
Point(3) = { 0.5*len, 0.5*wid, 0, d1};
Point(4) = {-0.5*len, 0.5*wid, 0, d1};

Line(1) = {1, 2};
Line(2) = {2, 3};
Line(3) = {3, 4};
Line(4) = {4, 1};

Point(5) = {0, 0, 0, d3};
Point(6) = {0, 0+rad, 0, d3};
Point(7) = {0+rad, 0, 0, d3};
Point(8) = {0, 0-rad, 0, d3};
Point(9) = {0-rad, 0, 0, d3};

Circle(5) = {6, 5, 7};
Circle(6) = {7, 5, 8};
Circle(7) = {8, 5, 9};
Circle(8) = {9, 5, 6};

Line Loop(13) = {1,2,3,4};
Line Loop(14) = {5,6,7,8};

Plane Surface(15) = {13,14};
//Plane Surface(8) = {13};

Physical Line(7) = {1}; //S
Physical Line(8) = {2}; //E
Physical Line(9) = {3}; //N
Physical Line(10) = {4}; //W
Physical Line(11) = {5,6,7,8}; //pier
Physical Surface(12) = {15};

# --- pier_scour.flml ---
<?xml version="1.0" encoding="utf-8" ?>
<fluidity_options>
<simulation_name>
<string_value lines="1">pier_scour</string_value>
</simulation_name>
<problem_type>
<string_value lines="1">fluids</string_value>
</problem_type>
<geometry>
<dimension>
<integer_value rank="0">3</integer_value>
</dimension>
<mesh name="CoordinateMesh">
<from_mesh>
<mesh name="BaseMesh"></mesh>
<mesh_shape>
<polynomial_degree>
<integer_value rank="0">1</integer_value>
</polynomial_degree>
</mesh_shape>
<stat>
<include_in_stat></include_in_stat>
</stat>
</from_mesh>
</mesh>
<mesh name="VelocityMesh">
<from_mesh>
<mesh name="BaseMesh"></mesh>
<mesh_shape>
<polynomial_degree>
<integer_value rank="0">1</integer_value>
</polynomial_degree>
</mesh_shape>
<mesh_continuity>
<string_value>discontinuous</string_value>
</mesh_continuity>
<stat>
<exclude_from_stat></exclude_from_stat>
</stat>
</from_mesh>
</mesh>
<mesh name="PressureMesh">
<from_mesh>
<mesh name="BaseMesh"></mesh>
<mesh_shape>
<polynomial_degree>
<integer_value rank="0">2</integer_value>
</polynomial_degree>
</mesh_shape>
<stat>
<exclude_from_stat></exclude_from_stat>
</stat>
</from_mesh>
</mesh>
<mesh name="InputMesh">
<from_file file_name="pier_scour_flredecomp_InputMesh">
<format name="triangle"></format>
<stat>
<exclude_from_stat></exclude_from_stat>
</stat>
</from_file>
</mesh>
<mesh name="BaseMesh">
<from_mesh>
<mesh name="InputMesh"></mesh>
<extrude>
<regions name="WholeMesh">
<bottom_depth>
<constant>
<real_value rank="0">0.07</real_value>
<comment>0.07</comment>
</constant>
</bottom_depth>
<sizing_function>
<constant>
<real_value rank="0">0.01</real_value>
</constant>
</sizing_function>
<top_surface_id>
<integer_value rank="0">307</integer_value>
</top_surface_id>
<bottom_surface_id>
<integer_value rank="0">308</integer_value>
</bottom_surface_id>
</regions>
</extrude>
<stat>
<include_in_stat></include_in_stat>
</stat>
</from_mesh>
</mesh>
<degree>
<integer_value rank="0">4</integer_value>
<comment>4</comment>
</degree>
<ocean_boundaries>
<top_surface_ids>
<integer_value rank="1" shape="1">307</integer_value>
</top_surface_ids>
<bottom_surface_ids>
<integer_value rank="1" shape="1">308</integer_value>
</bottom_surface_ids>
<scalar_field name="DistanceToTop" rank="0">
<diagnostic>
<algorithm name="Internal" material_phase_support="multiple"></algorithm>
<mesh name="CoordinateMesh"></mesh>
<output></output>
<stat></stat>
<convergence>
<include_in_convergence></include_in_convergence>
</convergence>
<detectors>
<include_in_detectors></include_in_detectors>
</detectors>
</diagnostic>
</scalar_field>
<scalar_field name="DistanceToBottom" rank="0">
<diagnostic>
<algorithm name="Internal" material_phase_support="multiple"></algorithm>
<mesh name="CoordinateMesh"></mesh>
<output>
<exclude_from_vtu></exclude_from_vtu>
</output>
<stat></stat>
<convergence>
<include_in_convergence></include_in_convergence>
</convergence>
<detectors>
<include_in_detectors></include_in_detectors>
</detectors>
</diagnostic>
</scalar_field>
</ocean_boundaries>
</geometry>
<io>
<dump_format>
<string_value>vtk</string_value>
</dump_format>
<dump_period>
<python>
<string_value lines="20" type="code" language="python">def val(t):&#x0A; if t&lt;2.5:&#x0A; return 0.25&#x0A; elif t&lt;20:&#x0A; return 1.0&#x0A; else:&#x0A; return 5.0</string_value>
</python>
</dump_period>
<output_mesh name="VelocityMesh"></output_mesh>
<checkpointing>
<checkpoint_period_in_dumps>
<integer_value rank="0">100</integer_value>
</checkpoint_period_in_dumps>
<checkpoint_at_end></checkpoint_at_end>
</checkpointing>
<stat></stat>
</io>
<timestepping>
<current_time>
<real_value rank="0">0</real_value>
<time_units date="seconds since 1987-01-05 00:00.0"></time_units>
</current_time>
<timestep>
<real_value rank="0">0.005</real_value>
</timestep>
<finish_time>
<real_value rank="0">7200</real_value>
</finish_time>
<nonlinear_iterations>
<integer_value rank="0">2</integer_value>
</nonlinear_iterations>
</timestepping>
<physical_parameters>
<gravity>
<magnitude>
<real_value rank="0">9.81</real_value>
</magnitude>
<vector_field name="GravityDirection" rank="1">
<prescribed>
<mesh name="CoordinateMesh"></mesh>
<value name="gravity">
<constant>
<real_value rank="1" shape="3" dim1="dim">0 0 -1</real_value>
</constant>
</value>
<output>
<exclude_from_vtu></exclude_from_vtu>
</output>
<stat>
<include_in_stat></include_in_stat>
</stat>
<detectors>
<exclude_from_detectors></exclude_from_detectors>
</detectors>
</prescribed>
</vector_field>
</gravity>
</physical_parameters>
<material_phase name="Fields">
<equation_of_state>
<fluids>
<linear>
<reference_density>
<real_value rank="0">1</real_value>
</reference_density>
<subtract_out_hydrostatic_level></subtract_out_hydrostatic_level>
</linear>
</fluids>
</equation_of_state>
<subgridscale_parameterisations>
<k-epsilon>
<scalar_field name="TurbulentKineticEnergy" rank="0">
<prognostic>
<mesh name="VelocityMesh"></mesh>
<spatial_discretisation>
<control_volumes>
<face_value name="FiniteElement">
<limit_face_value>
<limiter name="Sweby">
<project_upwind_value_from_point>
<store_upwind_elements>
</store_upwind_elements>
</project_upwind_value_from_point>
</limiter>
</limit_face_value>
</face_value>
</control_volumes>
<real_value rank="0">0</real_value>
</spatial_discretisation>
<temporal_discretisation>
<theta>
<real_value rank="0">0.5</real_value>
</theta>
<control_volumes>
<integer_value rank="0">3</integer_value>
</control_volumes>
</temporal_discretisation>
<solver>
<iterative_method name="gmres">
<restart>
<integer_value rank="0">30</integer_value>
</restart>
</iterative_method>
<preconditioner name="sor"></preconditioner>
<relative_error>
<real_value rank="0">1e-07</real_value>
</relative_error>
<max_iterations>
<integer_value rank="0">6001</integer_value>
</max_iterations>
<never_ignore_solver_failures></never_ignore_solver_failures>
<diagnostics>
<monitors></monitors>
</diagnostics>
</solver>
<initial_condition name="WholeMesh">
<constant>
<real_value rank="0">0</real_value>
</constant>
</initial_condition>
<boundary_conditions name="P_B_k_eps">
<surface_ids>
<integer_value rank="1" shape="2">11 308</integer_value>
</surface_ids>
<type name="k_epsilon">
<string_value>low_Re</string_value>
</type>
</boundary_conditions>
<tensor_field name="Diffusivity" rank="2">
<diagnostic>
<algorithm name="Internal" material_phase_support="multiple"></algorithm>
<output></output>
<stat>
<include_in_stat></include_in_stat>
</stat>
</diagnostic>
</tensor_field>
<scalar_field name="Source" rank="0">
<diagnostic>
<algorithm name="Internal" material_phase_support="multiple"></algorithm>
<output></output>
<stat></stat>
<detectors>
<include_in_detectors></include_in_detectors>
</detectors>
</diagnostic>
</scalar_field>
<scalar_field name="Absorption" rank="0">
<diagnostic>
<algorithm name="Internal" material_phase_support="multiple"></algorithm>
<output></output>
<stat></stat>
<detectors>
<include_in_detectors></include_in_detectors>
</detectors>
</diagnostic>
</scalar_field>
<output></output>
<stat></stat>
<convergence>
<include_in_convergence></include_in_convergence>
</convergence>
<detectors>
<include_in_detectors></include_in_detectors>
</detectors>
<consistent_interpolation></consistent_interpolation>
</prognostic>
</scalar_field>
<scalar_field name="TurbulentDissipation" rank="0">
<prognostic>
<mesh name="VelocityMesh"></mesh>
<spatial_discretisation>
<control_volumes>
<face_value name="FiniteElement">
<limit_face_value>
<limiter name="Sweby">
<project_upwind_value_from_point>
<store_upwind_elements>
</store_upwind_elements>
</project_upwind_value_from_point>
</limiter>
</limit_face_value>
</face_value>
</control_volumes>
<real_value rank="0">0</real_value>
</spatial_discretisation>
<temporal_discretisation>
<theta>
<real_value rank="0">0.5</real_value>
</theta>
<control_volumes>
<integer_value rank="0">3</integer_value>
</control_volumes>
</temporal_discretisation>
<solver>
<iterative_method name="gmres">
<restart>
<integer_value rank="0">30</integer_value>
</restart>
</iterative_method>
<preconditioner name="sor"></preconditioner>
<relative_error>
<real_value rank="0">1e-07</real_value>
</relative_error>
<max_iterations>
<integer_value rank="0">6002</integer_value>
</max_iterations>
<never_ignore_solver_failures></never_ignore_solver_failures>
<diagnostics>
<monitors></monitors>
</diagnostics>
</solver>
<initial_condition name="WholeMesh">
<constant>
<real_value rank="0">0</real_value>
</constant>
</initial_condition>
<boundary_conditions name="P_B_kepsilon">
<surface_ids>
<integer_value rank="1" shape="2">11 308</integer_value>
</surface_ids>
<type name="k_epsilon">
<string_value>low_Re</string_value>
</type>
</boundary_conditions>
<tensor_field name="Diffusivity" rank="2">
<diagnostic>
<algorithm name="Internal" material_phase_support="multiple"></algorithm>
<output></output>
<stat>
<include_in_stat></include_in_stat>
</stat>
</diagnostic>
</tensor_field>
<scalar_field name="Source" rank="0">
<diagnostic>
<algorithm name="Internal" material_phase_support="multiple"></algorithm>
<output></output>
<stat></stat>
<detectors>
<include_in_detectors></include_in_detectors>
</detectors>
</diagnostic>
</scalar_field>
<scalar_field name="Absorption" rank="0">
<diagnostic>
<algorithm name="Internal" material_phase_support="multiple"></algorithm>
<output></output>
<stat></stat>
<detectors>
<include_in_detectors></include_in_detectors>
</detectors>
</diagnostic>
</scalar_field>
<output></output>
<stat></stat>
<convergence>
<include_in_convergence></include_in_convergence>
</convergence>
<detectors>
<include_in_detectors></include_in_detectors>
</detectors>
<consistent_interpolation></consistent_interpolation>
</prognostic>
</scalar_field>
<tensor_field name="BackgroundViscosity" rank="2">
<prescribed>
<mesh name="VelocityMesh"></mesh>
<value name="WholeMesh">
<anisotropic_symmetric>
<constant>
<real_value rank="2" shape="3 3" symmetric="true" dim2="dim" dim1="dim">0.012 0.012 0.012 0.012 0.012 0.012 0.012 0.012 0.012</real_value>
</constant>
</anisotropic_symmetric>
</value>
<output></output>
</prescribed>
</tensor_field>
<tensor_field name="EddyViscosity" rank="2">
<diagnostic>
<algorithm name="Internal" material_phase_support="multiple"></algorithm>
<mesh name="VelocityMesh"></mesh>
<output></output>
<stat>
<include_in_stat></include_in_stat>
</stat>
</diagnostic>
</tensor_field>
<scalar_field name="ScalarEddyViscosity" rank="0">
<diagnostic>
<algorithm name="Internal" material_phase_support="multiple"></algorithm>
<mesh name="VelocityMesh"></mesh>
<output></output>
<stat></stat>
<convergence>
<include_in_convergence></include_in_convergence>
</convergence>
<detectors>
<include_in_detectors></include_in_detectors>
</detectors>
</diagnostic>
</scalar_field>
<scalar_field name="LengthScale" rank="0">
<diagnostic>
<algorithm name="Internal" material_phase_support="multiple"></algorithm>
<mesh name="VelocityMesh"></mesh>
<output></output>
<stat></stat>
<convergence>
<include_in_convergence></include_in_convergence>
</convergence>
<detectors>
<include_in_detectors></include_in_detectors>
</detectors>
</diagnostic>
</scalar_field>
<scalar_field name="f_1" rank="0">
<diagnostic>
<algorithm name="Internal" material_phase_support="multiple"></algorithm>
<mesh name="VelocityMesh"></mesh>
<output></output>
<stat></stat>
<convergence>
<include_in_convergence></include_in_convergence>
</convergence>
<detectors>
<include_in_detectors></include_in_detectors>
</detectors>
</diagnostic>
</scalar_field>
<scalar_field name="f_2" rank="0">
<diagnostic>
<algorithm name="Internal" material_phase_support="multiple"></algorithm>
<mesh name="VelocityMesh"></mesh>
<output></output>
<stat></stat>
<convergence>
<include_in_convergence></include_in_convergence>
</convergence>
<detectors>
<include_in_detectors></include_in_detectors>
</detectors>
</diagnostic>
</scalar_field>
<scalar_field name="f_mu" rank="0">
<diagnostic>
<algorithm name="Internal" material_phase_support="multiple"></algorithm>
<mesh name="VelocityMesh"></mesh>
<output></output>
<stat></stat>
<convergence>
<include_in_convergence></include_in_convergence>
</convergence>
<detectors>
<include_in_detectors></include_in_detectors>
</detectors>
</diagnostic>
</scalar_field>
<max_damping_value>
<real_value rank="0">10</real_value>
</max_damping_value>
<scalar_field name="DistanceToWall" rank="0">
<prescribed>
<mesh name="VelocityMesh"></mesh>
<value name="WholeMesh">
<python>
<string_value lines="20" type="code" language="python">def val(X,t):&#x0D;&#x0A; xc=0.0 # x at circile center &#x0D;&#x0A; yc=0.0 # y at circile center &#x0A; rad=0.03 # radius 0.03&#x0A; dep=0.07 # depth 0.07&#x0D;&#x0A; val=((X[0]-xc)**2+(X[1]-yc)**2)**0.5 - rad&#x0A;# if more close to bottom &#x0D;&#x0A; if val&gt;(dep+X[2]): &#x0A; val=dep+X[2]&#x0A; if val&lt;0:&#x0A; val=0&#x0A; &#x0A; return val</string_value>
</python>
</value>
<output></output>
<stat></stat>
<detectors>
<exclude_from_detectors></exclude_from_detectors>
</detectors>
</prescribed>
</scalar_field>
<C_mu>
<real_value rank="0">0.09</real_value>
</C_mu>
<C_eps_1>
<real_value rank="0">1.44</real_value>
</C_eps_1>
<C_eps_2>
<real_value rank="0">1.92</real_value>
</C_eps_2>
<sigma_k>
<real_value rank="0">1</real_value>
</sigma_k>
<sigma_eps>
<real_value rank="0">1.3</real_value>
</sigma_eps>
<sigma_p>
<real_value rank="0">1</real_value>
</sigma_p>
<time_discretisation>
<theta>
<real_value rank="0">0.5</real_value>
</theta>
<source_term_implementation>
<production_term>source</production_term>
<destruction_term>absorbtion</destruction_term>
<buoyancy_term>source</buoyancy_term>
</source_term_implementation>
</time_discretisation>
<mass_terms>
<lump_mass></lump_mass>
</mass_terms>
</k-epsilon>
</subgridscale_parameterisations>
<scalar_field name="Pressure" rank="0">
<prognostic>
<mesh name="PressureMesh"></mesh>
<spatial_discretisation>
<continuous_galerkin>
<remove_stabilisation_term></remove_stabilisation_term>
<integrate_continuity_by_parts></integrate_continuity_by_parts>
</continuous_galerkin>
</spatial_discretisation>
<scheme>
<poisson_pressure_solution>
<string_value lines="1">never</string_value>
</poisson_pressure_solution>
<use_projection_method></use_projection_method>
</scheme>
<solver>
<iterative_method name="cg"></iterative_method>
<preconditioner name="mg">
<vertical_lumping></vertical_lumping>
</preconditioner>
<relative_error>
<real_value rank="0">1e-07</real_value>
</relative_error>
<max_iterations>
<integer_value rank="0">3000</integer_value>
</max_iterations>
<never_ignore_solver_failures></never_ignore_solver_failures>
<diagnostics>
<monitors></monitors>
</diagnostics>
</solver>
<output></output>
<stat></stat>
<convergence>
<include_in_convergence></include_in_convergence>
</convergence>
<detectors>
<exclude_from_detectors></exclude_from_detectors>
</detectors>
<consistent_interpolation></consistent_interpolation>
</prognostic>
</scalar_field>
<vector_field name="Velocity" rank="1">
<prognostic>
<mesh name="VelocityMesh"></mesh>
<equation name="Boussinesq"></equation>
<spatial_discretisation>
<discontinuous_galerkin>
<viscosity_scheme>
<compact_discontinuous_galerkin></compact_discontinuous_galerkin>
<tensor_form></tensor_form>
</viscosity_scheme>
<upwind></upwind>
<project_velocity_to_continuous>
<mesh name="CoordinateMesh"></mesh>
</project_velocity_to_continuous>
<twice></twice>
</discontinuous_galerkin>
<real_value rank="0">0</real_value>
</spatial_discretisation>
<temporal_discretisation>
<theta>
<real_value rank="0">1</real_value>
</theta>
<relaxation>
<real_value rank="0">1</real_value>
</relaxation>
<discontinuous_galerkin>
<maximum_courant_number_per_subcycle>
<real_value rank="0">0.1</real_value>
</maximum_courant_number_per_subcycle>
</discontinuous_galerkin>
</temporal_discretisation>
<solver>
<iterative_method name="gmres">
<restart>
<integer_value rank="0">30</integer_value>
</restart>
</iterative_method>
<preconditioner name="sor"></preconditioner>
<relative_error>
<real_value rank="0">1e-07</real_value>
</relative_error>
<max_iterations>
<integer_value rank="0">10000</integer_value>
</max_iterations>
<never_ignore_solver_failures></never_ignore_solver_failures>
<diagnostics>
<monitors></monitors>
</diagnostics>
</solver>
<initial_condition name="WholeMesh">
<constant>
<real_value rank="1" shape="3" dim1="dim">0 0 0</real_value>
</constant>
</initial_condition>
<boundary_conditions name="B_drag">
<surface_ids>
<integer_value rank="1" shape="1">308</integer_value>
</surface_ids>
<type name="drag">
<constant>
<real_value rank="0">0.0025</real_value>
<comment>0.0025</comment>
</constant>
</type>
</boundary_conditions>
<boundary_conditions name="T_FreeSurface">
<surface_ids>
<integer_value rank="1" shape="1">307</integer_value>
</surface_ids>
<type name="free_surface"></type>
</boundary_conditions>
<boundary_conditions name="P_B_NoNormalFlow">
<surface_ids>
<integer_value rank="1" shape="2">11 308</integer_value>
</surface_ids>
<type name="no_normal_flow"></type>
</boundary_conditions>
<boundary_conditions name="W_const_Vel">
<surface_ids>
<integer_value rank="1" shape="1">10</integer_value>
</surface_ids>
<type name="dirichlet">
<apply_weakly></apply_weakly>
<align_bc_with_cartesian>
<x_component>
<constant>
<real_value rank="0">0.2</real_value>
<comment>def val(X,t):&#x0A; amp=0.5&#x0A; if (t&lt;10):&#x0A; val=amp*t/10&#x0A; else:&#x0A; val=amp&#x0A;&#x0A; return val</comment>
</constant>
</x_component>
</align_bc_with_cartesian>
</type>
</boundary_conditions>
<boundary_conditions name="S_N_FREESLIP">
<surface_ids>
<integer_value rank="1" shape="2">7 9</integer_value>
</surface_ids>
<type name="dirichlet">
<apply_weakly></apply_weakly>
<align_bc_with_cartesian>
<y_component>
<constant>
<real_value rank="0">0</real_value>
</constant>
</y_component>
</align_bc_with_cartesian>
</type>
</boundary_conditions>
<tensor_field name="Viscosity" rank="2">
<diagnostic>
<algorithm name="Internal" material_phase_support="multiple"></algorithm>
<output></output>
<stat>
<include_in_stat></include_in_stat>
</stat>
</diagnostic>
</tensor_field>
<vertical_stabilization>
<implicit_buoyancy></implicit_buoyancy>
</vertical_stabilization>
<output></output>
<stat>
<include_in_stat></include_in_stat>
<previous_time_step>
<exclude_from_stat></exclude_from_stat>
</previous_time_step>
<nonlinear_field>
<exclude_from_stat></exclude_from_stat>
</nonlinear_field>
</stat>
<convergence>
<include_in_convergence></include_in_convergence>
</convergence>
<detectors>
<include_in_detectors></include_in_detectors>
</detectors>
<consistent_interpolation></consistent_interpolation>
</prognostic>
</vector_field>
<scalar_field name="FreeSurface" rank="0">
<diagnostic>
<algorithm name="Internal" material_phase_support="multiple"></algorithm>
<mesh name="PressureMesh"></mesh>
<output></output>
<stat></stat>
<convergence>
<include_in_convergence></include_in_convergence>
</convergence>
<detectors>
<include_in_detectors></include_in_detectors>
</detectors>
</diagnostic>
</scalar_field>
<scalar_field name="DG_CourantNumber" rank="0">
<diagnostic>
<algorithm name="Internal" material_phase_support="multiple"></algorithm>
<mesh name="VelocityMesh"></mesh>
<output>
<exclude_from_vtu></exclude_from_vtu>
</output>
<stat></stat>
<convergence>
<include_in_convergence></include_in_convergence>
</convergence>
<detectors>
<include_in_detectors></include_in_detectors>
</detectors>
</diagnostic>
</scalar_field>
<vector_field name="BedShearStress" rank="1">
<diagnostic>
<algorithm name="Internal" material_phase_support="multiple"></algorithm>
<mesh name="VelocityMesh"></mesh>
<density>
<real_value rank="0">1000</real_value>
</density>
<calculation_method>
<drag_coefficient>
<real_value rank="0">0.0025</real_value>
<comment>2.5e-3</comment>
</drag_coefficient>
</calculation_method>
<output></output>
<stat>
<include_in_stat></include_in_stat>
</stat>
<detectors>
<include_in_detectors></include_in_detectors>
</detectors>
</diagnostic>
</vector_field>
<sediment>
<scalar_field name="sed1" rank="0">
<prognostic>
<mesh name="VelocityMesh"></mesh>
<spatial_discretisation>
<control_volumes>
<face_value name="FiniteElement">
<limit_face_value>
<limiter name="Sweby">
<project_upwind_value_from_point>
<store_upwind_elements>
</store_upwind_elements>
</project_upwind_value_from_point>
</limiter>
</limit_face_value>
</face_value>
</control_volumes>
<real_value rank="0">0</real_value>
</spatial_discretisation>
<temporal_discretisation>
<theta>
<real_value rank="0">0.5</real_value>
</theta>
<control_volumes>
<integer_value rank="0">3</integer_value>
<limit_theta></limit_theta>
</control_volumes>
</temporal_discretisation>
<solver>
<iterative_method name="gmres">
<restart>
<integer_value rank="0">30</integer_value>
</restart>
</iterative_method>
<preconditioner name="sor"></preconditioner>
<relative_error>
<real_value rank="0">1e-07</real_value>
</relative_error>
<max_iterations>
<integer_value rank="0">2000</integer_value>
</max_iterations>
<never_ignore_solver_failures></never_ignore_solver_failures>
<diagnostics>
<monitors></monitors>
</diagnostics>
</solver>
<initial_condition name="WholeMesh">
<constant>
<real_value rank="0">0</real_value>
</constant>
</initial_condition>
<boundary_conditions name="B_sed_re">
<surface_ids>
<integer_value rank="1" shape="1">308</integer_value>
</surface_ids>
<type name="sediment_reentrainment">
<algorithm>Garcia_1991</algorithm>
</type>
</boundary_conditions>
<boundary_conditions name="ZeroFlux_S_N_W_P_T">
<surface_ids>
<integer_value rank="1" shape="5">7 9 10 11 307</integer_value>
</surface_ids>
<type name="zero_flux"></type>
</boundary_conditions>
<boundary_conditions name="E_Neum">
<surface_ids>
<integer_value rank="1" shape="1">8</integer_value>
</surface_ids>
<type name="neumann">
<constant>
<real_value rank="0">0</real_value>
</constant>
</type>
</boundary_conditions>
<tensor_field name="Diffusivity" rank="2">
<prescribed>
<value name="WholeMesh">
<isotropic>
<constant>
<real_value rank="0">1e-10</real_value>
</constant>
</isotropic>
</value>
<output></output>
</prescribed>
</tensor_field>
<scalar_field name="SinkingVelocity" rank="0">
<diagnostic>
<mesh name="VelocityMesh"></mesh>
<algorithm name="Internal" material_phase_support="multiple"></algorithm>
<output></output>
<stat></stat>
<detectors>
<include_in_detectors></include_in_detectors>
</detectors>
</diagnostic>
</scalar_field>
<output></output>
<stat></stat>
<convergence>
<include_in_convergence></include_in_convergence>
</convergence>
<detectors>
<include_in_detectors></include_in_detectors>
</detectors>
<consistent_interpolation></consistent_interpolation>
<prognostic>
<surface_ids>
<integer_value rank="1" shape="1">308</integer_value>
</surface_ids>
<spatial_discretisation>
<control_volumes>
<face_value name="FiniteElement">
<limit_face_value>
<limiter name="Sweby">
<project_upwind_value_from_point>
<store_upwind_elements>
</store_upwind_elements>
</project_upwind_value_from_point>
</limiter>
</limit_face_value>
</face_value>
</control_volumes>
<real_value rank="0">0</real_value>
</spatial_discretisation>
<temporal_discretisation>
<theta>
<real_value rank="0">0.5</real_value>
</theta>
<control_volumes>
<integer_value rank="0">3</integer_value>
<limit_theta></limit_theta>
</control_volumes>
</temporal_discretisation>
<solver>
<iterative_method name="gmres">
<restart>
<integer_value rank="0">30</integer_value>
</restart>
</iterative_method>
<preconditioner name="sor"></preconditioner>
<relative_error>
<real_value rank="0">1e-07</real_value>
</relative_error>
<max_iterations>
<integer_value rank="0">1000</integer_value>
</max_iterations>
<never_ignore_solver_failures></never_ignore_solver_failures>
<diagnostics>
<monitors></monitors>
</diagnostics>
</solver>
<initial_condition name="WholeMesh">
<constant>
<real_value rank="0">0.04</real_value>
</constant>
</initial_condition>
<output></output>
<stat></stat>
<convergence>
<include_in_convergence></include_in_convergence>
</convergence>
<detectors>
<include_in_detectors></include_in_detectors>
</detectors>
<consistent_interpolation></consistent_interpolation>
</prognostic>
</scalar_field>
<diagnostic>
<output>
<exclude_from_vtu></exclude_from_vtu>
</output>
<stat></stat>
<convergence>
<include_in_convergence></include_in_convergence>
</convergence>
<detectors>
<include_in_detectors></include_in_detectors>
</detectors>
</diagnostic>
</scalar_field>
<diagnostic>
<output></output>
<stat></stat>
<convergence>
<include_in_convergence></include_in_convergence>
</convergence>
<detectors>
<include_in_detectors></include_in_detectors>
</detectors>
</diagnostic>
</scalar_field>
<diagnostic>
<output></output>
<stat></stat>
<convergence>
<include_in_convergence></include_in_convergence>
</convergence>
<detectors>
<include_in_detectors></include_in_detectors>
</detectors>
</diagnostic>
</scalar_field>
<scalar_field name="UnhinderedSinkingVelocity" rank="0">
<prescribed>
<mesh name="VelocityMesh"></mesh>
<value name="WholeMesh">
<constant>
<real_value rank="0">0.0133</real_value>
<comment>0.014</comment>
</constant>
</value>
<output>
<exclude_from_vtu></exclude_from_vtu>
</output>
<stat></stat>
<detectors>
<exclude_from_detectors></exclude_from_detectors>
</detectors>
</prescribed>
</scalar_field>
<submerged_specific_gravity>
<real_value rank="0">1.69</real_value>
<comment>1.65</comment>
</submerged_specific_gravity>
<diameter>
<real_value rank="0">0.00107</real_value>
<comment>0.000125</comment>
</diameter>
<bed_porosity>
<real_value rank="0">0.3</real_value>
</bed_porosity>
<erodability>
<real_value rank="0">1</real_value>
</erodability>
</prognostic>
</scalar_field>
<scalar_field name="SedimentBedActiveLayerD50" rank="0">
<diagnostic>
<surface_ids>
<integer_value rank="1" shape="1">308</integer_value>
</surface_ids>
<algorithm name="Internal" material_phase_support="multiple"></algorithm>
<mesh name="VelocityMesh"></mesh>
<output>
<exclude_from_vtu></exclude_from_vtu>
</output>
<stat></stat>
<convergence>
<include_in_convergence></include_in_convergence>
</convergence>
<detectors>
<include_in_detectors></include_in_detectors>
</detectors>
</diagnostic>
</scalar_field>
<scalar_field name="SedimentBedActiveLayerSigma" rank="0">
<diagnostic>
<surface_ids>
<integer_value rank="1" shape="1">308</integer_value>
</surface_ids>
<algorithm name="Internal" material_phase_support="multiple"></algorithm>
<mesh name="VelocityMesh"></mesh>
<output>
<exclude_from_vtu></exclude_from_vtu>
</output>
<stat></stat>
<convergence>
<include_in_convergence></include_in_convergence>
</convergence>
<detectors>
<include_in_detectors></include_in_detectors>
</detectors>
</diagnostic>
</scalar_field>
<tensor_field name="ZeroSedimentConcentrationViscosity" rank="2">
<prescribed>
<mesh name="VelocityMesh"></mesh>
<value name="WholeMesh">
<isotropic>
<constant>
<real_value rank="0">0.001</real_value>
</constant>
</isotropic>
</value>
<output></output>
</prescribed>
</tensor_field>
</sediment>
</material_phase>
</fluidity_options>

## Question information

Language:
English Edit question
Status:
Solved
For:
Fluidity Edit question
Assignee:
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Solved by:
Samuel Parkinson
Solved:
Last query:
 Revision history for this message Jon Hill (jon-hill) said on 2014-01-02: #1

Hi there,

K-E model is difficult to get stable at times. Try turning it off and
checking for a stable run first. Add a reasonable amount diffusion and
viscosity to ensure stability. Once the run is stable, try adding the
K-E back in.

Hope that helps,

Jon

On 25/12/2013 07:06, liu chin chi wrote:
> New question #241254 on Fluidity:
>
> dear all,
> i've try to simulate a local scour around a pier with sediment model build in FLUIDITY.
>
> subgridscale parameterisations/kepsilon is be used and kepsilon boundary is be applied to bottom and pier sides.but the "TurbulentDissipation" around the pier surface would increase greatly with time.
>
> I've try to turn off sediment model, or modify the grid resolution and background viscosity but still
> can't let "TurbulentDissipation" stable.
>
> any comment is appreciated. thanks.
>
> # box set
> Length:0.36 m
> Width:0.36 m
> Height:0.07 m
>
> # velocity boundary
> west : a constant velocity 0.2 m/s (inlet)
> east : zero-gradient boundary conditions (outlet)
> south and north : free slide wall
> top : free surface
> bottom : no normal flow and drag
> pier : no normal flow
>
> the geo and flml content is attached below.
>
> # --- pier_scour.geo ---
> d1=0.03; //0.03
> d3=0.01; //0.01
> len=0.36; //0.36
> wid=0.36; //0.36
> Point(1) = {-0.5*len, -0.5*wid, 0, d1};
> Point(2) = { 0.5*len, -0.5*wid, 0, d1};
> Point(3) = { 0.5*len, 0.5*wid, 0, d1};
> Point(4) = {-0.5*len, 0.5*wid, 0, d1};
>
> Line(1) = {1, 2};
> Line(2) = {2, 3};
> Line(3) = {3, 4};
> Line(4) = {4, 1};
>
> Point(5) = {0, 0, 0, d3};
> Point(6) = {0, 0+rad, 0, d3};
> Point(7) = {0+rad, 0, 0, d3};
> Point(8) = {0, 0-rad, 0, d3};
> Point(9) = {0-rad, 0, 0, d3};
>
> Circle(5) = {6, 5, 7};
> Circle(6) = {7, 5, 8};
> Circle(7) = {8, 5, 9};
> Circle(8) = {9, 5, 6};
>
> Line Loop(13) = {1,2,3,4};
> Line Loop(14) = {5,6,7,8};
>
> Plane Surface(15) = {13,14};
> //Plane Surface(8) = {13};
>
> Physical Line(7) = {1}; //S
> Physical Line(8) = {2}; //E
> Physical Line(9) = {3}; //N
> Physical Line(10) = {4}; //W
> Physical Line(11) = {5,6,7,8}; //pier
> Physical Surface(12) = {15};
>
> # --- pier_scour.flml ---
> <?xml version="1.0" encoding="utf-8" ?>
> <fluidity_options>
> <simulation_name>
> <string_value lines="1">pier_scour</string_value>
> </simulation_name>
> <problem_type>
> <string_value lines="1">fluids</string_value>
> </problem_type>
> <geometry>
> <dimension>
> <integer_value rank="0">3</integer_value>
> </dimension>
> <mesh name="CoordinateMesh">
> <from_mesh>
> <mesh name="BaseMesh"></mesh>
> <mesh_shape>
> <polynomial_degree>
> <integer_value rank="0">1</integer_value>
> </polynomial_degree>
> </mesh_shape>
> <stat>
> <include_in_stat></include_in_stat>
> </stat>
> </from_mesh>
> </mesh>
> <mesh name="VelocityMesh">
> <from_mesh>
> <mesh name="BaseMesh"></mesh>
> <mesh_shape>
> <polynomial_degree>
> <integer_value rank="0">1</integer_value>
> </polynomial_degree>
> </mesh_shape>
> <mesh_continuity>
> <string_value>discontinuous</string_value>
> </mesh_continuity>
> <stat>
> <exclude_from_stat></exclude_from_stat>
> </stat>
> </from_mesh>
> </mesh>
> <mesh name="PressureMesh">
> <from_mesh>
> <mesh name="BaseMesh"></mesh>
> <mesh_shape>
> <polynomial_degree>
> <integer_value rank="0">2</integer_value>
> </polynomial_degree>
> </mesh_shape>
> <stat>
> <exclude_from_stat></exclude_from_stat>
> </stat>
> </from_mesh>
> </mesh>
> <mesh name="InputMesh">
> <from_file file_name="pier_scour_flredecomp_InputMesh">
> <format name="triangle"></format>
> <stat>
> <exclude_from_stat></exclude_from_stat>
> </stat>
> </from_file>
> </mesh>
> <mesh name="BaseMesh">
> <from_mesh>
> <mesh name="InputMesh"></mesh>
> <extrude>
> <regions name="WholeMesh">
> <bottom_depth>
> <constant>
> <real_value rank="0">0.07</real_value>
> <comment>0.07</comment>
> </constant>
> </bottom_depth>
> <sizing_function>
> <constant>
> <real_value rank="0">0.01</real_value>
> </constant>
> </sizing_function>
> <top_surface_id>
> <integer_value rank="0">307</integer_value>
> </top_surface_id>
> <bottom_surface_id>
> <integer_value rank="0">308</integer_value>
> </bottom_surface_id>
> </regions>
> </extrude>
> <stat>
> <include_in_stat></include_in_stat>
> </stat>
> </from_mesh>
> </mesh>
> <degree>
> <integer_value rank="0">4</integer_value>
> <comment>4</comment>
> </degree>
> <ocean_boundaries>
> <top_surface_ids>
> <integer_value rank="1" shape="1">307</integer_value>
> </top_surface_ids>
> <bottom_surface_ids>
> <integer_value rank="1" shape="1">308</integer_value>
> </bottom_surface_ids>
> <scalar_field name="DistanceToTop" rank="0">
> <diagnostic>
> <algorithm name="Internal" material_phase_support="multiple"></algorithm>
> <mesh name="CoordinateMesh"></mesh>
> <output></output>
> <stat></stat>
> <convergence>
> <include_in_convergence></include_in_convergence>
> </convergence>
> <detectors>
> <include_in_detectors></include_in_detectors>
> </detectors>
> </diagnostic>
> </scalar_field>
> <scalar_field name="DistanceToBottom" rank="0">
> <diagnostic>
> <algorithm name="Internal" material_phase_support="multiple"></algorithm>
> <mesh name="CoordinateMesh"></mesh>
> <output>
> <exclude_from_vtu></exclude_from_vtu>
> </output>
> <stat></stat>
> <convergence>
> <include_in_convergence></include_in_convergence>
> </convergence>
> <detectors>
> <include_in_detectors></include_in_detectors>
> </detectors>
> </diagnostic>
> </scalar_field>
> </ocean_boundaries>
> </geometry>
> <io>
> <dump_format>
> <string_value>vtk</string_value>
> </dump_format>
> <dump_period>
> <python>
> <string_value lines="20" type="code" language="python">def val(t):&#x0A; if t&lt;2.5:&#x0A; return 0.25&#x0A; elif t&lt;20:&#x0A; return 1.0&#x0A; else:&#x0A; return 5.0</string_value>
> </python>
> </dump_period>
> <output_mesh name="VelocityMesh"></output_mesh>
> <checkpointing>
> <checkpoint_period_in_dumps>
> <integer_value rank="0">100</integer_value>
> </checkpoint_period_in_dumps>
> <checkpoint_at_end></checkpoint_at_end>
> </checkpointing>
> <stat></stat>
> </io>
> <timestepping>
> <current_time>
> <real_value rank="0">0</real_value>
> <time_units date="seconds since 1987-01-05 00:00.0"></time_units>
> </current_time>
> <timestep>
> <real_value rank="0">0.005</real_value>
> </timestep>
> <finish_time>
> <real_value rank="0">7200</real_value>
> </finish_time>
> <nonlinear_iterations>
> <integer_value rank="0">2</integer_value>
> </nonlinear_iterations>
> </timestepping>
> <physical_parameters>
> <gravity>
> <magnitude>
> <real_value rank="0">9.81</real_value>
> </magnitude>
> <vector_field name="GravityDirection" rank="1">
> <prescribed>
> <mesh name="CoordinateMesh"></mesh>
> <value name="gravity">
> <constant>
> <real_value rank="1" shape="3" dim1="dim">0 0 -1</real_value>
> </constant>
> </value>
> <output>
> <exclude_from_vtu></exclude_from_vtu>
> </output>
> <stat>
> <include_in_stat></include_in_stat>
> </stat>
> <detectors>
> <exclude_from_detectors></exclude_from_detectors>
> </detectors>
> </prescribed>
> </vector_field>
> </gravity>
> </physical_parameters>
> <material_phase name="Fields">
> <equation_of_state>
> <fluids>
> <linear>
> <reference_density>
> <real_value rank="0">1</real_value>
> </reference_density>
> <subtract_out_hydrostatic_level></subtract_out_hydrostatic_level>
> </linear>
> </fluids>
> </equation_of_state>
> <subgridscale_parameterisations>
> <k-epsilon>
> <scalar_field name="TurbulentKineticEnergy" rank="0">
> <prognostic>
> <mesh name="VelocityMesh"></mesh>
> <spatial_discretisation>
> <control_volumes>
> <face_value name="FiniteElement">
> <limit_face_value>
> <limiter name="Sweby">
> <project_upwind_value_from_point>
> <store_upwind_elements>
> </store_upwind_elements>
> </project_upwind_value_from_point>
> </limiter>
> </limit_face_value>
> </face_value>
> </control_volumes>
> <real_value rank="0">0</real_value>
> </spatial_discretisation>
> <temporal_discretisation>
> <theta>
> <real_value rank="0">0.5</real_value>
> </theta>
> <control_volumes>
> <integer_value rank="0">3</integer_value>
> </control_volumes>
> </temporal_discretisation>
> <solver>
> <iterative_method name="gmres">
> <restart>
> <integer_value rank="0">30</integer_value>
> </restart>
> </iterative_method>
> <preconditioner name="sor"></preconditioner>
> <relative_error>
> <real_value rank="0">1e-07</real_value>
> </relative_error>
> <max_iterations>
> <integer_value rank="0">6001</integer_value>
> </max_iterations>
> <never_ignore_solver_failures></never_ignore_solver_failures>
> <diagnostics>
> <monitors></monitors>
> </diagnostics>
> </solver>
> <initial_condition name="WholeMesh">
> <constant>
> <real_value rank="0">0</real_value>
> </constant>
> </initial_condition>
> <boundary_conditions name="P_B_k_eps">
> <surface_ids>
> <integer_value rank="1" shape="2">11 308</integer_value>
> </surface_ids>
> <type name="k_epsilon">
> <string_value>low_Re</string_value>
> </type>
> </boundary_conditions>
> <tensor_field name="Diffusivity" rank="2">
> <diagnostic>
> <algorithm name="Internal" material_phase_support="multiple"></algorithm>
> <output></output>
> <stat>
> <include_in_stat></include_in_stat>
> </stat>
> </diagnostic>
> </tensor_field>
> <scalar_field name="Source" rank="0">
> <diagnostic>
> <algorithm name="Internal" material_phase_support="multiple"></algorithm>
> <output></output>
> <stat></stat>
> <detectors>
> <include_in_detectors></include_in_detectors>
> </detectors>
> </diagnostic>
> </scalar_field>
> <scalar_field name="Absorption" rank="0">
> <diagnostic>
> <algorithm name="Internal" material_phase_support="multiple"></algorithm>
> <output></output>
> <stat></stat>
> <detectors>
> <include_in_detectors></include_in_detectors>
> </detectors>
> </diagnostic>
> </scalar_field>
> <output></output>
> <stat></stat>
> <convergence>
> <include_in_convergence></include_in_convergence>
> </convergence>
> <detectors>
> <include_in_detectors></include_in_detectors>
> </detectors>
> <consistent_interpolation></consistent_interpolation>
> </prognostic>
> </scalar_field>
> <scalar_field name="TurbulentDissipation" rank="0">
> <prognostic>
> <mesh name="VelocityMesh"></mesh>
> <spatial_discretisation>
> <control_volumes>
> <face_value name="FiniteElement">
> <limit_face_value>
> <limiter name="Sweby">
> <project_upwind_value_from_point>
> <store_upwind_elements>
> </store_upwind_elements>
> </project_upwind_value_from_point>
> </limiter>
> </limit_face_value>
> </face_value>
> </control_volumes>
> <real_value rank="0">0</real_value>
> </spatial_discretisation>
> <temporal_discretisation>
> <theta>
> <real_value rank="0">0.5</real_value>
> </theta>
> <control_volumes>
> <integer_value rank="0">3</integer_value>
> </control_volumes>
> </temporal_discretisation>
> <solver>
> <iterative_method name="gmres">
> <restart>
> <integer_value rank="0">30</integer_value>
> </restart>
> </iterative_method>
> <preconditioner name="sor"></preconditioner>
> <relative_error>
> <real_value rank="0">1e-07</real_value>
> </relative_error>
> <max_iterations>
> <integer_value rank="0">6002</integer_value>
> </max_iterations>
> <never_ignore_solver_failures></never_ignore_solver_failures>
> <diagnostics>
> <monitors></monitors>
> </diagnostics>
> </solver>
> <initial_condition name="WholeMesh">
> <constant>
> <real_value rank="0">0</real_value>
> </constant>
> </initial_condition>
> <boundary_conditions name="P_B_kepsilon">
> <surface_ids>
> <integer_value rank="1" shape="2">11 308</integer_value>
> </surface_ids>
> <type name="k_epsilon">
> <string_value>low_Re</string_value>
> </type>
> </boundary_conditions>
> <tensor_field name="Diffusivity" rank="2">
> <diagnostic>
> <algorithm name="Internal" material_phase_support="multiple"></algorithm>
> <output></output>
> <stat>
> <include_in_stat></include_in_stat>
> </stat>
> </diagnostic>
> </tensor_field>
> <scalar_field name="Source" rank="0">
> <diagnostic>
> <algorithm name="Internal" material_phase_support="multiple"></algorithm>
> <output></output>
> <stat></stat>
> <detectors>
> <include_in_detectors></include_in_detectors>
> </detectors>
> </diagnostic>
> </scalar_field>
> <scalar_field name="Absorption" rank="0">
> <diagnostic>
> <algorithm name="Internal" material_phase_support="multiple"></algorithm>
> <output></output>
> <stat></stat>
> <detectors>
> <include_in_detectors></include_in_detectors>
> </detectors>
> </diagnostic>
> </scalar_field>
> <output></output>
> <stat></stat>
> <convergence>
> <include_in_convergence></include_in_convergence>
> </convergence>
> <detectors>
> <include_in_detectors></include_in_detectors>
> </detectors>
> <consistent_interpolation></consistent_interpolation>
> </prognostic>
> </scalar_field>
> <tensor_field name="BackgroundViscosity" rank="2">
> <prescribed>
> <mesh name="VelocityMesh"></mesh>
> <value name="WholeMesh">
> <anisotropic_symmetric>
> <constant>
> <real_value rank="2" shape="3 3" symmetric="true" dim2="dim" dim1="dim">0.012 0.012 0.012 0.012 0.012 0.012 0.012 0.012 0.012</real_value>
> </constant>
> </anisotropic_symmetric>
> </value>
> <output></output>
> </prescribed>
> </tensor_field>
> <tensor_field name="EddyViscosity" rank="2">
> <diagnostic>
> <algorithm name="Internal" material_phase_support="multiple"></algorithm>
> <mesh name="VelocityMesh"></mesh>
> <output></output>
> <stat>
> <include_in_stat></include_in_stat>
> </stat>
> </diagnostic>
> </tensor_field>
> <scalar_field name="ScalarEddyViscosity" rank="0">
> <diagnostic>
> <algorithm name="Internal" material_phase_support="multiple"></algorithm>
> <mesh name="VelocityMesh"></mesh>
> <output></output>
> <stat></stat>
> <convergence>
> <include_in_convergence></include_in_convergence>
> </convergence>
> <detectors>
> <include_in_detectors></include_in_detectors>
> </detectors>
> </diagnostic>
> </scalar_field>
> <scalar_field name="LengthScale" rank="0">
> <diagnostic>
> <algorithm name="Internal" material_phase_support="multiple"></algorithm>
> <mesh name="VelocityMesh"></mesh>
> <output></output>
> <stat></stat>
> <convergence>
> <include_in_convergence></include_in_convergence>
> </convergence>
> <detectors>
> <include_in_detectors></include_in_detectors>
> </detectors>
> </diagnostic>
> </scalar_field>
> <scalar_field name="f_1" rank="0">
> <diagnostic>
> <algorithm name="Internal" material_phase_support="multiple"></algorithm>
> <mesh name="VelocityMesh"></mesh>
> <output></output>
> <stat></stat>
> <convergence>
> <include_in_convergence></include_in_convergence>
> </convergence>
> <detectors>
> <include_in_detectors></include_in_detectors>
> </detectors>
> </diagnostic>
> </scalar_field>
> <scalar_field name="f_2" rank="0">
> <diagnostic>
> <algorithm name="Internal" material_phase_support="multiple"></algorithm>
> <mesh name="VelocityMesh"></mesh>
> <output></output>
> <stat></stat>
> <convergence>
> <include_in_convergence></include_in_convergence>
> </convergence>
> <detectors>
> <include_in_detectors></include_in_detectors>
> </detectors>
> </diagnostic>
> </scalar_field>
> <scalar_field name="f_mu" rank="0">
> <diagnostic>
> <algorithm name="Internal" material_phase_support="multiple"></algorithm>
> <mesh name="VelocityMesh"></mesh>
> <output></output>
> <stat></stat>
> <convergence>
> <include_in_convergence></include_in_convergence>
> </convergence>
> <detectors>
> <include_in_detectors></include_in_detectors>
> </detectors>
> </diagnostic>
> </scalar_field>
> <max_damping_value>
> <real_value rank="0">10</real_value>
> </max_damping_value>
> <scalar_field name="DistanceToWall" rank="0">
> <prescribed>
> <mesh name="VelocityMesh"></mesh>
> <value name="WholeMesh">
> <python>
> <string_value lines="20" type="code" language="python">def val(X,t):&#x0D;&#x0A; xc=0.0 # x at circile center &#x0D;&#x0A; yc=0.0 # y at circile center &#x0A; rad=0.03 # radius 0.03&#x0A; dep=0.07 # depth 0.07&#x0D;&#x0A; val=((X[0]-xc)**2+(X[1]-yc)**2)**0.5 - rad&#x0A;# if more close to bottom &#x0D;&#x0A; if val&gt;(dep+X[2]): &#x0A; val=dep+X[2]&#x0A; if val&lt;0:&#x0A; val=0&#x0A; &#x0A; return val</string_value>
> </python>
> </value>
> <output></output>
> <stat></stat>
> <detectors>
> <exclude_from_detectors></exclude_from_detectors>
> </detectors>
> </prescribed>
> </scalar_field>
> <C_mu>
> <real_value rank="0">0.09</real_value>
> </C_mu>
> <C_eps_1>
> <real_value rank="0">1.44</real_value>
> </C_eps_1>
> <C_eps_2>
> <real_value rank="0">1.92</real_value>
> </C_eps_2>
> <sigma_k>
> <real_value rank="0">1</real_value>
> </sigma_k>
> <sigma_eps>
> <real_value rank="0">1.3</real_value>
> </sigma_eps>
> <sigma_p>
> <real_value rank="0">1</real_value>
> </sigma_p>
> <time_discretisation>
> <theta>
> <real_value rank="0">0.5</real_value>
> </theta>
> <source_term_implementation>
> <production_term>source</production_term>
> <destruction_term>absorbtion</destruction_term>
> <buoyancy_term>source</buoyancy_term>
> </source_term_implementation>
> </time_discretisation>
> <mass_terms>
> <lump_mass></lump_mass>
> </mass_terms>
> </k-epsilon>
> </subgridscale_parameterisations>
> <scalar_field name="Pressure" rank="0">
> <prognostic>
> <mesh name="PressureMesh"></mesh>
> <spatial_discretisation>
> <continuous_galerkin>
> <remove_stabilisation_term></remove_stabilisation_term>
> <integrate_continuity_by_parts></integrate_continuity_by_parts>
> </continuous_galerkin>
> </spatial_discretisation>
> <scheme>
> <poisson_pressure_solution>
> <string_value lines="1">never</string_value>
> </poisson_pressure_solution>
> <use_projection_method></use_projection_method>
> </scheme>
> <solver>
> <iterative_method name="cg"></iterative_method>
> <preconditioner name="mg">
> <vertical_lumping></vertical_lumping>
> </preconditioner>
> <relative_error>
> <real_value rank="0">1e-07</real_value>
> </relative_error>
> <max_iterations>
> <integer_value rank="0">3000</integer_value>
> </max_iterations>
> <never_ignore_solver_failures></never_ignore_solver_failures>
> <diagnostics>
> <monitors></monitors>
> </diagnostics>
> </solver>
> <output></output>
> <stat></stat>
> <convergence>
> <include_in_convergence></include_in_convergence>
> </convergence>
> <detectors>
> <exclude_from_detectors></exclude_from_detectors>
> </detectors>
> <consistent_interpolation></consistent_interpolation>
> </prognostic>
> </scalar_field>
> <vector_field name="Velocity" rank="1">
> <prognostic>
> <mesh name="VelocityMesh"></mesh>
> <equation name="Boussinesq"></equation>
> <spatial_discretisation>
> <discontinuous_galerkin>
> <viscosity_scheme>
> <compact_discontinuous_galerkin></compact_discontinuous_galerkin>
> <tensor_form></tensor_form>
> </viscosity_scheme>
> <upwind></upwind>
> <project_velocity_to_continuous>
> <mesh name="CoordinateMesh"></mesh>
> </project_velocity_to_continuous>
> <twice></twice>
> </discontinuous_galerkin>
> <real_value rank="0">0</real_value>
> </spatial_discretisation>
> <temporal_discretisation>
> <theta>
> <real_value rank="0">1</real_value>
> </theta>
> <relaxation>
> <real_value rank="0">1</real_value>
> </relaxation>
> <discontinuous_galerkin>
> <maximum_courant_number_per_subcycle>
> <real_value rank="0">0.1</real_value>
> </maximum_courant_number_per_subcycle>
> </discontinuous_galerkin>
> </temporal_discretisation>
> <solver>
> <iterative_method name="gmres">
> <restart>
> <integer_value rank="0">30</integer_value>
> </restart>
> </iterative_method>
> <preconditioner name="sor"></preconditioner>
> <relative_error>
> <real_value rank="0">1e-07</real_value>
> </relative_error>
> <max_iterations>
> <integer_value rank="0">10000</integer_value>
> </max_iterations>
> <never_ignore_solver_failures></never_ignore_solver_failures>
> <diagnostics>
> <monitors></monitors>
> </diagnostics>
> </solver>
> <initial_condition name="WholeMesh">
> <constant>
> <real_value rank="1" shape="3" dim1="dim">0 0 0</real_value>
> </constant>
> </initial_condition>
> <boundary_conditions name="B_drag">
> <surface_ids>
> <integer_value rank="1" shape="1">308</integer_value>
> </surface_ids>
> <type name="drag">
> <constant>
> <real_value rank="0">0.0025</real_value>
> <comment>0.0025</comment>
> </constant>
> </type>
> </boundary_conditions>
> <boundary_conditions name="T_FreeSurface">
> <surface_ids>
> <integer_value rank="1" shape="1">307</integer_value>
> </surface_ids>
> <type name="free_surface"></type>
> </boundary_conditions>
> <boundary_conditions name="P_B_NoNormalFlow">
> <surface_ids>
> <integer_value rank="1" shape="2">11 308</integer_value>
> </surface_ids>
> <type name="no_normal_flow"></type>
> </boundary_conditions>
> <boundary_conditions name="W_const_Vel">
> <surface_ids>
> <integer_value rank="1" shape="1">10</integer_value>
> </surface_ids>
> <type name="dirichlet">
> <apply_weakly></apply_weakly>
> <align_bc_with_cartesian>
> <x_component>
> <constant>
> <real_value rank="0">0.2</real_value>
> <comment>def val(X,t):&#x0A; amp=0.5&#x0A; if (t&lt;10):&#x0A; val=amp*t/10&#x0A; else:&#x0A; val=amp&#x0A;&#x0A; return val</comment>
> </constant>
> </x_component>
> </align_bc_with_cartesian>
> </type>
> </boundary_conditions>
> <boundary_conditions name="S_N_FREESLIP">
> <surface_ids>
> <integer_value rank="1" shape="2">7 9</integer_value>
> </surface_ids>
> <type name="dirichlet">
> <apply_weakly></apply_weakly>
> <align_bc_with_cartesian>
> <y_component>
> <constant>
> <real_value rank="0">0</real_value>
> </constant>
> </y_component>
> </align_bc_with_cartesian>
> </type>
> </boundary_conditions>
> <tensor_field name="Viscosity" rank="2">
> <diagnostic>
> <algorithm name="Internal" material_phase_support="multiple"></algorithm>
> <output></output>
> <stat>
> <include_in_stat></include_in_stat>
> </stat>
> </diagnostic>
> </tensor_field>
> <vertical_stabilization>
> <implicit_buoyancy></implicit_buoyancy>
> </vertical_stabilization>
> <output></output>
> <stat>
> <include_in_stat></include_in_stat>
> <previous_time_step>
> <exclude_from_stat></exclude_from_stat>
> </previous_time_step>
> <nonlinear_field>
> <exclude_from_stat></exclude_from_stat>
> </nonlinear_field>
> </stat>
> <convergence>
> <include_in_convergence></include_in_convergence>
> </convergence>
> <detectors>
> <include_in_detectors></include_in_detectors>
> </detectors>
> <consistent_interpolation></consistent_interpolation>
> </prognostic>
> </vector_field>
> <scalar_field name="FreeSurface" rank="0">
> <diagnostic>
> <algorithm name="Internal" material_phase_support="multiple"></algorithm>
> <mesh name="PressureMesh"></mesh>
> <output></output>
> <stat></stat>
> <convergence>
> <include_in_convergence></include_in_convergence>
> </convergence>
> <detectors>
> <include_in_detectors></include_in_detectors>
> </detectors>
> </diagnostic>
> </scalar_field>
> <scalar_field name="DG_CourantNumber" rank="0">
> <diagnostic>
> <algorithm name="Internal" material_phase_support="multiple"></algorithm>
> <mesh name="VelocityMesh"></mesh>
> <output>
> <exclude_from_vtu></exclude_from_vtu>
> </output>
> <stat></stat>
> <convergence>
> <include_in_convergence></include_in_convergence>
> </convergence>
> <detectors>
> <include_in_detectors></include_in_detectors>
> </detectors>
> </diagnostic>
> </scalar_field>
> <vector_field name="BedShearStress" rank="1">
> <diagnostic>
> <algorithm name="Internal" material_phase_support="multiple"></algorithm>
> <mesh name="VelocityMesh"></mesh>
> <density>
> <real_value rank="0">1000</real_value>
> </density>
> <calculation_method>
> <drag_coefficient>
> <real_value rank="0">0.0025</real_value>
> <comment>2.5e-3</comment>
> </drag_coefficient>
> </calculation_method>
> <output></output>
> <stat>
> <include_in_stat></include_in_stat>
> </stat>
> <detectors>
> <include_in_detectors></include_in_detectors>
> </detectors>
> </diagnostic>
> </vector_field>
> <sediment>
> <scalar_field name="sed1" rank="0">
> <prognostic>
> <mesh name="VelocityMesh"></mesh>
> <spatial_discretisation>
> <control_volumes>
> <face_value name="FiniteElement">
> <limit_face_value>
> <limiter name="Sweby">
> <project_upwind_value_from_point>
> <store_upwind_elements>
> </store_upwind_elements>
> </project_upwind_value_from_point>
> </limiter>
> </limit_face_value>
> </face_value>
> </control_volumes>
> <real_value rank="0">0</real_value>
> </spatial_discretisation>
> <temporal_discretisation>
> <theta>
> <real_value rank="0">0.5</real_value>
> </theta>
> <control_volumes>
> <integer_value rank="0">3</integer_value>
> <limit_theta></limit_theta>
> </control_volumes>
> </temporal_discretisation>
> <solver>
> <iterative_method name="gmres">
> <restart>
> <integer_value rank="0">30</integer_value>
> </restart>
> </iterative_method>
> <preconditioner name="sor"></preconditioner>
> <relative_error>
> <real_value rank="0">1e-07</real_value>
> </relative_error>
> <max_iterations>
> <integer_value rank="0">2000</integer_value>
> </max_iterations>
> <never_ignore_solver_failures></never_ignore_solver_failures>
> <diagnostics>
> <monitors></monitors>
> </diagnostics>
> </solver>
> <initial_condition name="WholeMesh">
> <constant>
> <real_value rank="0">0</real_value>
> </constant>
> </initial_condition>
> <boundary_conditions name="B_sed_re">
> <surface_ids>
> <integer_value rank="1" shape="1">308</integer_value>
> </surface_ids>
> <type name="sediment_reentrainment">
> <algorithm>Garcia_1991</algorithm>
> </type>
> </boundary_conditions>
> <boundary_conditions name="ZeroFlux_S_N_W_P_T">
> <surface_ids>
> <integer_value rank="1" shape="5">7 9 10 11 307</integer_value>
> </surface_ids>
> <type name="zero_flux"></type>
> </boundary_conditions>
> <boundary_conditions name="E_Neum">
> <surface_ids>
> <integer_value rank="1" shape="1">8</integer_value>
> </surface_ids>
> <type name="neumann">
> <constant>
> <real_value rank="0">0</real_value>
> </constant>
> </type>
> </boundary_conditions>
> <tensor_field name="Diffusivity" rank="2">
> <prescribed>
> <value name="WholeMesh">
> <isotropic>
> <constant>
> <real_value rank="0">1e-10</real_value>
> </constant>
> </isotropic>
> </value>
> <output></output>
> </prescribed>
> </tensor_field>
> <scalar_field name="SinkingVelocity" rank="0">
> <diagnostic>
> <mesh name="VelocityMesh"></mesh>
> <algorithm name="Internal" material_phase_support="multiple"></algorithm>
> <output></output>
> <stat></stat>
> <detectors>
> <include_in_detectors></include_in_detectors>
> </detectors>
> </diagnostic>
> </scalar_field>
> <output></output>
> <stat></stat>
> <convergence>
> <include_in_convergence></include_in_convergence>
> </convergence>
> <detectors>
> <include_in_detectors></include_in_detectors>
> </detectors>
> <consistent_interpolation></consistent_interpolation>
> <prognostic>
> <surface_ids>
> <integer_value rank="1" shape="1">308</integer_value>
> </surface_ids>
> <spatial_discretisation>
> <control_volumes>
> <face_value name="FiniteElement">
> <limit_face_value>
> <limiter name="Sweby">
> <project_upwind_value_from_point>
> <store_upwind_elements>
> </store_upwind_elements>
> </project_upwind_value_from_point>
> </limiter>
> </limit_face_value>
> </face_value>
> </control_volumes>
> <real_value rank="0">0</real_value>
> </spatial_discretisation>
> <temporal_discretisation>
> <theta>
> <real_value rank="0">0.5</real_value>
> </theta>
> <control_volumes>
> <integer_value rank="0">3</integer_value>
> <limit_theta></limit_theta>
> </control_volumes>
> </temporal_discretisation>
> <solver>
> <iterative_method name="gmres">
> <restart>
> <integer_value rank="0">30</integer_value>
> </restart>
> </iterative_method>
> <preconditioner name="sor"></preconditioner>
> <relative_error>
> <real_value rank="0">1e-07</real_value>
> </relative_error>
> <max_iterations>
> <integer_value rank="0">1000</integer_value>
> </max_iterations>
> <never_ignore_solver_failures></never_ignore_solver_failures>
> <diagnostics>
> <monitors></monitors>
> </diagnostics>
> </solver>
> <initial_condition name="WholeMesh">
> <constant>
> <real_value rank="0">0.04</real_value>
> </constant>
> </initial_condition>
> <output></output>
> <stat></stat>
> <convergence>
> <include_in_convergence></include_in_convergence>
> </convergence>
> <detectors>
> <include_in_detectors></include_in_detectors>
> </detectors>
> <consistent_interpolation></consistent_interpolation>
> </prognostic>
> </scalar_field>
> <diagnostic>
> <output>
> <exclude_from_vtu></exclude_from_vtu>
> </output>
> <stat></stat>
> <convergence>
> <include_in_convergence></include_in_convergence>
> </convergence>
> <detectors>
> <include_in_detectors></include_in_detectors>
> </detectors>
> </diagnostic>
> </scalar_field>
> <diagnostic>
> <output></output>
> <stat></stat>
> <convergence>
> <include_in_convergence></include_in_convergence>
> </convergence>
> <detectors>
> <include_in_detectors></include_in_detectors>
> </detectors>
> </diagnostic>
> </scalar_field>
> <diagnostic>
> <output></output>
> <stat></stat>
> <convergence>
> <include_in_convergence></include_in_convergence>
> </convergence>
> <detectors>
> <include_in_detectors></include_in_detectors>
> </detectors>
> </diagnostic>
> </scalar_field>
> <scalar_field name="UnhinderedSinkingVelocity" rank="0">
> <prescribed>
> <mesh name="VelocityMesh"></mesh>
> <value name="WholeMesh">
> <constant>
> <real_value rank="0">0.0133</real_value>
> <comment>0.014</comment>
> </constant>
> </value>
> <output>
> <exclude_from_vtu></exclude_from_vtu>
> </output>
> <stat></stat>
> <detectors>
> <exclude_from_detectors></exclude_from_detectors>
> </detectors>
> </prescribed>
> </scalar_field>
> <submerged_specific_gravity>
> <real_value rank="0">1.69</real_value>
> <comment>1.65</comment>
> </submerged_specific_gravity>
> <diameter>
> <real_value rank="0">0.00107</real_value>
> <comment>0.000125</comment>
> </diameter>
> <bed_porosity>
> <real_value rank="0">0.3</real_value>
> </bed_porosity>
> <erodability>
> <real_value rank="0">1</real_value>
> </erodability>
> </prognostic>
> </scalar_field>
> <scalar_field name="SedimentBedActiveLayerD50" rank="0">
> <diagnostic>
> <surface_ids>
> <integer_value rank="1" shape="1">308</integer_value>
> </surface_ids>
> <algorithm name="Internal" material_phase_support="multiple"></algorithm>
> <mesh name="VelocityMesh"></mesh>
> <output>
> <exclude_from_vtu></exclude_from_vtu>
> </output>
> <stat></stat>
> <convergence>
> <include_in_convergence></include_in_convergence>
> </convergence>
> <detectors>
> <include_in_detectors></include_in_detectors>
> </detectors>
> </diagnostic>
> </scalar_field>
> <scalar_field name="SedimentBedActiveLayerSigma" rank="0">
> <diagnostic>
> <surface_ids>
> <integer_value rank="1" shape="1">308</integer_value>
> </surface_ids>
> <algorithm name="Internal" material_phase_support="multiple"></algorithm>
> <mesh name="VelocityMesh"></mesh>
> <output>
> <exclude_from_vtu></exclude_from_vtu>
> </output>
> <stat></stat>
> <convergence>
> <include_in_convergence></include_in_convergence>
> </convergence>
> <detectors>
> <include_in_detectors></include_in_detectors>
> </detectors>
> </diagnostic>
> </scalar_field>
> <tensor_field name="ZeroSedimentConcentrationViscosity" rank="2">
> <prescribed>
> <mesh name="VelocityMesh"></mesh>
> <value name="WholeMesh">
> <isotropic>
> <constant>
> <real_value rank="0">0.001</real_value>
> </constant>
> </isotropic>
> </value>
> <output></output>
> </prescribed>
> </tensor_field>
> </sediment>
> </material_phase>
> </fluidity_options>
>

--
Dr Jon Hill
Research Fellow
AMCG, Earth Science and Engineering
Imperial College London
Mob: 07748254812
Phone: +44(0)2075949321

 Revision history for this message Samuel Parkinson (s-parkinson11) said on 2014-01-03: #2

Hello Liu,

I agree with Jon about the way forward. I would just liker to add that I am
not sure your boundary condition around the pier and on the bottom surface
are valid. K-epsilon is only implemented with a low-re boundary condition.
This assumes a no-slip condition for velocity and could be why dissipation
is blowing up around the pier.

I would recommend applying no slip conditions and having significantly
higher resolution at these no slip boundaries to resolve the boundary layer
sufficiently.

Cheers,

Sam
On 2 Jan 2014 16:31, "Jon Hill" <email address hidden>
wrote:

> Question #241254 on Fluidity changed:
>
>
> Jon Hill proposed the following answer:
> Hi there,
>
> K-E model is difficult to get stable at times. Try turning it off and
> checking for a stable run first. Add a reasonable amount diffusion and
> viscosity to ensure stability. Once the run is stable, try adding the
> K-E back in.
>
> Hope that helps,
>
> Jon
>
> On 25/12/2013 07:06, liu chin chi wrote:
> > New question #241254 on Fluidity:
> >
> > dear all,
> > i've try to simulate a local scour around a pier with sediment model
> build in FLUIDITY.
> >
> > subgridscale parameterisations/kepsilon is be used and kepsilon boundary
> is be applied to bottom and pier sides.but the "TurbulentDissipation"
> around the pier surface would increase greatly with time.
> >
> > I've try to turn off sediment model, or modify the grid resolution and
> background viscosity but still
> > can't let "TurbulentDissipation" stable.
> >
> > any comment is appreciated. thanks.
> >
> > # box set
> > Length:0.36 m
> > Width:0.36 m
> > Height:0.07 m
> >
> > # velocity boundary
> > west : a constant velocity 0.2 m/s (inlet)
> > east : zero-gradient boundary conditions (outlet)
> > south and north : free slide wall
> > top : free surface
> > bottom : no normal flow and drag
> > pier : no normal flow
> >
> > the geo and flml content is attached below.
> >
> > # --- pier_scour.geo ---
> > rad = 0.03; //0.03
> > d1=0.03; //0.03
> > d3=0.01; //0.01
> > len=0.36; //0.36
> > wid=0.36; //0.36
> > Point(1) = {-0.5*len, -0.5*wid, 0, d1};
> > Point(2) = { 0.5*len, -0.5*wid, 0, d1};
> > Point(3) = { 0.5*len, 0.5*wid, 0, d1};
> > Point(4) = {-0.5*len, 0.5*wid, 0, d1};
> >
> > Line(1) = {1, 2};
> > Line(2) = {2, 3};
> > Line(3) = {3, 4};
> > Line(4) = {4, 1};
> >
> > Point(5) = {0, 0, 0, d3};
> > Point(6) = {0, 0+rad, 0, d3};
> > Point(7) = {0+rad, 0, 0, d3};
> > Point(8) = {0, 0-rad, 0, d3};
> > Point(9) = {0-rad, 0, 0, d3};
> >
> > Circle(5) = {6, 5, 7};
> > Circle(6) = {7, 5, 8};
> > Circle(7) = {8, 5, 9};
> > Circle(8) = {9, 5, 6};
> >
> > Line Loop(13) = {1,2,3,4};
> > Line Loop(14) = {5,6,7,8};
> >
> > Plane Surface(15) = {13,14};
> > //Plane Surface(8) = {13};
> >
> > Physical Line(7) = {1}; //S
> > Physical Line(8) = {2}; //E
> > Physical Line(9) = {3}; //N
> > Physical Line(10) = {4}; //W
> > Physical Line(11) = {5,6,7,8}; //pier
> > Physical Surface(12) = {15};
> >
> > # --- pier_scour.flml ---
> > <?xml version="1.0" encoding="utf-8" ?>
> > <fluidity_options>
> > <simulation_name>
> > <string_value lines="1">pier_scour</string_value>
> > </simulation_name>
> > <problem_type>
> > <string_value lines="1">fluids</string_value>
> > </problem_type>
> > <geometry>
> > <dimension>
> > <integer_value rank="0">3</integer_value>
> > </dimension>
> > <mesh name="CoordinateMesh">
> > <from_mesh>
> > <mesh name="BaseMesh"></mesh>
> > <mesh_shape>
> > <polynomial_degree>
> > <integer_value rank="0">1</integer_value>
> > </polynomial_degree>
> > </mesh_shape>
> > <stat>
> > <include_in_stat></include_in_stat>
> > </stat>
> > </from_mesh>
> > </mesh>
> > <mesh name="VelocityMesh">
> > <from_mesh>
> > <mesh name="BaseMesh"></mesh>
> > <mesh_shape>
> > <polynomial_degree>
> > <integer_value rank="0">1</integer_value>
> > </polynomial_degree>
> > </mesh_shape>
> > <mesh_continuity>
> > <string_value>discontinuous</string_value>
> > </mesh_continuity>
> > <stat>
> > <exclude_from_stat></exclude_from_stat>
> > </stat>
> > </from_mesh>
> > </mesh>
> > <mesh name="PressureMesh">
> > <from_mesh>
> > <mesh name="BaseMesh"></mesh>
> > <mesh_shape>
> > <polynomial_degree>
> > <integer_value rank="0">2</integer_value>
> > </polynomial_degree>
> > </mesh_shape>
> > <stat>
> > <exclude_from_stat></exclude_from_stat>
> > </stat>
> > </from_mesh>
> > </mesh>
> > <mesh name="InputMesh">
> > <from_file file_name="pier_scour_flredecomp_InputMesh">
> > <format name="triangle"></format>
> > <stat>
> > <exclude_from_stat></exclude_from_stat>
> > </stat>
> > </from_file>
> > </mesh>
> > <mesh name="BaseMesh">
> > <from_mesh>
> > <mesh name="InputMesh"></mesh>
> > <extrude>
> > <regions name="WholeMesh">
> > <bottom_depth>
> > <constant>
> > <real_value rank="0">0.07</real_value>
> > <comment>0.07</comment>
> > </constant>
> > </bottom_depth>
> > <sizing_function>
> > <constant>
> > <real_value rank="0">0.01</real_value>
> > </constant>
> > </sizing_function>
> > <top_surface_id>
> > <integer_value rank="0">307</integer_value>
> > </top_surface_id>
> > <bottom_surface_id>
> > <integer_value rank="0">308</integer_value>
> > </bottom_surface_id>
> > </regions>
> > </extrude>
> > <stat>
> > <include_in_stat></include_in_stat>
> > </stat>
> > </from_mesh>
> > </mesh>
> > <degree>
> > <integer_value rank="0">4</integer_value>
> > <comment>4</comment>
> > </degree>
> > <ocean_boundaries>
> > <top_surface_ids>
> > <integer_value rank="1" shape="1">307</integer_value>
> > </top_surface_ids>
> > <bottom_surface_ids>
> > <integer_value rank="1" shape="1">308</integer_value>
> > </bottom_surface_ids>
> > <scalar_field name="DistanceToTop" rank="0">
> > <diagnostic>
> > <algorithm name="Internal"
> material_phase_support="multiple"></algorithm>
> > <mesh name="CoordinateMesh"></mesh>
> > <output></output>
> > <stat></stat>
> > <convergence>
> >
> <include_in_convergence></include_in_convergence>
> > </convergence>
> > <detectors>
> > <include_in_detectors></include_in_detectors>
> > </detectors>
> >
> > </diagnostic>
> > </scalar_field>
> > <scalar_field name="DistanceToBottom" rank="0">
> > <diagnostic>
> > <algorithm name="Internal"
> material_phase_support="multiple"></algorithm>
> > <mesh name="CoordinateMesh"></mesh>
> > <output>
> > <exclude_from_vtu></exclude_from_vtu>
> > </output>
> > <stat></stat>
> > <convergence>
> >
> <include_in_convergence></include_in_convergence>
> > </convergence>
> > <detectors>
> > <include_in_detectors></include_in_detectors>
> > </detectors>
> >
> > </diagnostic>
> > </scalar_field>
> > </ocean_boundaries>
> > </geometry>
> > <io>
> > <dump_format>
> > <string_value>vtk</string_value>
> > </dump_format>
> > <dump_period>
> > <python>
> > <string_value lines="20" type="code"
> language="python">def val(t):&#x0A; if t&lt;2.5:&#x0A; return
> 0.25&#x0A; elif t&lt;20:&#x0A; return 1.0&#x0A; else:&#x0A; return
> 5.0</string_value>
> > </python>
> > </dump_period>
> > <output_mesh name="VelocityMesh"></output_mesh>
> > <checkpointing>
> > <checkpoint_period_in_dumps>
> > <integer_value rank="0">100</integer_value>
> > </checkpoint_period_in_dumps>
> > <checkpoint_at_end></checkpoint_at_end>
> > </checkpointing>
> > <stat></stat>
> > </io>
> > <timestepping>
> > <current_time>
> > <real_value rank="0">0</real_value>
> > <time_units date="seconds since 1987-01-05
> 00:00.0"></time_units>
> > </current_time>
> > <timestep>
> > <real_value rank="0">0.005</real_value>
> > </timestep>
> > <finish_time>
> > <real_value rank="0">7200</real_value>
> > </finish_time>
> > <nonlinear_iterations>
> > <integer_value rank="0">2</integer_value>
> > </nonlinear_iterations>
> > </timestepping>
> > <physical_parameters>
> > <gravity>
> > <magnitude>
> > <real_value rank="0">9.81</real_value>
> > </magnitude>
> > <vector_field name="GravityDirection" rank="1">
> > <prescribed>
> > <mesh name="CoordinateMesh"></mesh>
> > <value name="gravity">
> > <constant>
> > <real_value rank="1" shape="3" dim1="dim">0
> 0 -1</real_value>
> > </constant>
> > </value>
> > <output>
> > <exclude_from_vtu></exclude_from_vtu>
> > </output>
> > <stat>
> > <include_in_stat></include_in_stat>
> > </stat>
> > <detectors>
> >
> <exclude_from_detectors></exclude_from_detectors>
> > </detectors>
> > </prescribed>
> > </vector_field>
> > </gravity>
> > </physical_parameters>
> > <material_phase name="Fields">
> > <equation_of_state>
> > <fluids>
> > <linear>
> > <reference_density>
> > <real_value rank="0">1</real_value>
> > </reference_density>
> >
> <subtract_out_hydrostatic_level></subtract_out_hydrostatic_level>
> > </linear>
> > </fluids>
> > </equation_of_state>
> > <subgridscale_parameterisations>
> > <k-epsilon>
> > <scalar_field name="TurbulentKineticEnergy" rank="0">
> > <prognostic>
> > <mesh name="VelocityMesh"></mesh>
> > <spatial_discretisation>
> > <control_volumes>
> > <face_value name="FiniteElement">
> > <limit_face_value>
> > <limiter name="Sweby">
> >
> <project_upwind_value_from_point>
> > <store_upwind_elements>
> >
> > </store_upwind_elements>
> >
> </project_upwind_value_from_point>
> > </limiter>
> > </limit_face_value>
> > </face_value>
> > <diffusion_scheme
> > </control_volumes>
> > <real_value rank="0">0</real_value>
> > </spatial_discretisation>
> > <temporal_discretisation>
> > <theta>
> > <real_value rank="0">0.5</real_value>
> > </theta>
> > <control_volumes>
> > <integer_value
> rank="0">3</integer_value>
> > </control_volumes>
> > </temporal_discretisation>
> > <solver>
> > <iterative_method name="gmres">
> > <restart>
> > <integer_value
> rank="0">30</integer_value>
> > </restart>
> > </iterative_method>
> > <preconditioner name="sor"></preconditioner>
> > <relative_error>
> > <real_value rank="0">1e-07</real_value>
> > </relative_error>
> > <max_iterations>
> > <integer_value
> rank="0">6001</integer_value>
> > </max_iterations>
> >
> <never_ignore_solver_failures></never_ignore_solver_failures>
> > <diagnostics>
> > <monitors></monitors>
> > </diagnostics>
> > </solver>
> > <initial_condition name="WholeMesh">
> > <constant>
> > <real_value rank="0">0</real_value>
> > </constant>
> > </initial_condition>
> > <boundary_conditions name="P_B_k_eps">
> > <surface_ids>
> > <integer_value rank="1" shape="2">11
> 308</integer_value>
> > </surface_ids>
> > <type name="k_epsilon">
> > <string_value>low_Re</string_value>
> > </type>
> > </boundary_conditions>
> > <tensor_field name="Diffusivity" rank="2">
> > <diagnostic>
> > <algorithm name="Internal"
> material_phase_support="multiple"></algorithm>
> > <output></output>
> > <stat>
> > <include_in_stat></include_in_stat>
> > </stat>
> > </diagnostic>
> > </tensor_field>
> > <scalar_field name="Source" rank="0">
> > <diagnostic>
> > <algorithm name="Internal"
> material_phase_support="multiple"></algorithm>
> > <output></output>
> > <stat></stat>
> > <detectors>
> >
> <include_in_detectors></include_in_detectors>
> > </detectors>
> > </diagnostic>
> > </scalar_field>
> > <scalar_field name="Absorption" rank="0">
> > <diagnostic>
> > <algorithm name="Internal"
> material_phase_support="multiple"></algorithm>
> > <output></output>
> > <stat></stat>
> > <detectors>
> >
> <include_in_detectors></include_in_detectors>
> > </detectors>
> > </diagnostic>
> > </scalar_field>
> > <output></output>
> > <stat></stat>
> > <convergence>
> >
> <include_in_convergence></include_in_convergence>
> > </convergence>
> > <detectors>
> >
> <include_in_detectors></include_in_detectors>
> > </detectors>
> >
> >
> <consistent_interpolation></consistent_interpolation>
> > </prognostic>
> > </scalar_field>
> > <scalar_field name="TurbulentDissipation" rank="0">
> > <prognostic>
> > <mesh name="VelocityMesh"></mesh>
> > <spatial_discretisation>
> > <control_volumes>
> > <face_value name="FiniteElement">
> > <limit_face_value>
> > <limiter name="Sweby">
> >
> <project_upwind_value_from_point>
> > <store_upwind_elements>
> >
> > </store_upwind_elements>
> >
> </project_upwind_value_from_point>
> > </limiter>
> > </limit_face_value>
> > </face_value>
> > <diffusion_scheme
> > </control_volumes>
> > <real_value rank="0">0</real_value>
> > </spatial_discretisation>
> > <temporal_discretisation>
> > <theta>
> > <real_value rank="0">0.5</real_value>
> > </theta>
> > <control_volumes>
> > <integer_value
> rank="0">3</integer_value>
> > </control_volumes>
> > </temporal_discretisation>
> > <solver>
> > <iterative_method name="gmres">
> > <restart>
> > <integer_value
> rank="0">30</integer_value>
> > </restart>
> > </iterative_method>
> > <preconditioner name="sor"></preconditioner>
> > <relative_error>
> > <real_value rank="0">1e-07</real_value>
> > </relative_error>
> > <max_iterations>
> > <integer_value
> rank="0">6002</integer_value>
> > </max_iterations>
> >
> <never_ignore_solver_failures></never_ignore_solver_failures>
> > <diagnostics>
> > <monitors></monitors>
> > </diagnostics>
> > </solver>
> > <initial_condition name="WholeMesh">
> > <constant>
> > <real_value rank="0">0</real_value>
> > </constant>
> > </initial_condition>
> > <boundary_conditions name="P_B_kepsilon">
> > <surface_ids>
> > <integer_value rank="1" shape="2">11
> 308</integer_value>
> > </surface_ids>
> > <type name="k_epsilon">
> > <string_value>low_Re</string_value>
> > </type>
> > </boundary_conditions>
> > <tensor_field name="Diffusivity" rank="2">
> > <diagnostic>
> > <algorithm name="Internal"
> material_phase_support="multiple"></algorithm>
> > <output></output>
> > <stat>
> > <include_in_stat></include_in_stat>
> > </stat>
> > </diagnostic>
> > </tensor_field>
> > <scalar_field name="Source" rank="0">
> > <diagnostic>
> > <algorithm name="Internal"
> material_phase_support="multiple"></algorithm>
> > <output></output>
> > <stat></stat>
> > <detectors>
> >
> <include_in_detectors></include_in_detectors>
> > </detectors>
> > </diagnostic>
> > </scalar_field>
> > <scalar_field name="Absorption" rank="0">
> > <diagnostic>
> > <algorithm name="Internal"
> material_phase_support="multiple"></algorithm>
> > <output></output>
> > <stat></stat>
> > <detectors>
> >
> <include_in_detectors></include_in_detectors>
> > </detectors>
> > </diagnostic>
> > </scalar_field>
> > <output></output>
> > <stat></stat>
> > <convergence>
> >
> <include_in_convergence></include_in_convergence>
> > </convergence>
> > <detectors>
> >
> <include_in_detectors></include_in_detectors>
> > </detectors>
> >
> >
> <consistent_interpolation></consistent_interpolation>
> > </prognostic>
> > </scalar_field>
> > <tensor_field name="BackgroundViscosity" rank="2">
> > <prescribed>
> > <mesh name="VelocityMesh"></mesh>
> > <value name="WholeMesh">
> > <anisotropic_symmetric>
> > <constant>
> > <real_value rank="2" shape="3 3"
> symmetric="true" dim2="dim" dim1="dim">0.012 0.012 0.012 0.012 0.012 0.012
> 0.012 0.012 0.012</real_value>
> > </constant>
> > </anisotropic_symmetric>
> > </value>
> > <output></output>
> > </prescribed>
> > </tensor_field>
> > <tensor_field name="EddyViscosity" rank="2">
> > <diagnostic>
> > <algorithm name="Internal"
> material_phase_support="multiple"></algorithm>
> > <mesh name="VelocityMesh"></mesh>
> > <output></output>
> > <stat>
> > <include_in_stat></include_in_stat>
> > </stat>
> > </diagnostic>
> > </tensor_field>
> > <scalar_field name="ScalarEddyViscosity" rank="0">
> > <diagnostic>
> > <algorithm name="Internal"
> material_phase_support="multiple"></algorithm>
> > <mesh name="VelocityMesh"></mesh>
> > <output></output>
> > <stat></stat>
> > <convergence>
> >
> <include_in_convergence></include_in_convergence>
> > </convergence>
> > <detectors>
> >
> <include_in_detectors></include_in_detectors>
> > </detectors>
> >
> > </diagnostic>
> > </scalar_field>
> > <scalar_field name="LengthScale" rank="0">
> > <diagnostic>
> > <algorithm name="Internal"
> material_phase_support="multiple"></algorithm>
> > <mesh name="VelocityMesh"></mesh>
> > <output></output>
> > <stat></stat>
> > <convergence>
> >
> <include_in_convergence></include_in_convergence>
> > </convergence>
> > <detectors>
> >
> <include_in_detectors></include_in_detectors>
> > </detectors>
> >
> > </diagnostic>
> > </scalar_field>
> > <scalar_field name="f_1" rank="0">
> > <diagnostic>
> > <algorithm name="Internal"
> material_phase_support="multiple"></algorithm>
> > <mesh name="VelocityMesh"></mesh>
> > <output></output>
> > <stat></stat>
> > <convergence>
> >
> <include_in_convergence></include_in_convergence>
> > </convergence>
> > <detectors>
> >
> <include_in_detectors></include_in_detectors>
> > </detectors>
> >
> > </diagnostic>
> > </scalar_field>
> > <scalar_field name="f_2" rank="0">
> > <diagnostic>
> > <algorithm name="Internal"
> material_phase_support="multiple"></algorithm>
> > <mesh name="VelocityMesh"></mesh>
> > <output></output>
> > <stat></stat>
> > <convergence>
> >
> <include_in_convergence></include_in_convergence>
> > </convergence>
> > <detectors>
> >
> <include_in_detectors></include_in_detectors>
> > </detectors>
> >
> > </diagnostic>
> > </scalar_field>
> > <scalar_field name="f_mu" rank="0">
> > <diagnostic>
> > <algorithm name="Internal"
> material_phase_support="multiple"></algorithm>
> > <mesh name="VelocityMesh"></mesh>
> > <output></output>
> > <stat></stat>
> > <convergence>
> >
> <include_in_convergence></include_in_convergence>
> > </convergence>
> > <detectors>
> >
> <include_in_detectors></include_in_detectors>
> > </detectors>
> >
> > </diagnostic>
> > </scalar_field>
> > <max_damping_value>
> > <real_value rank="0">10</real_value>
> > </max_damping_value>
> > <scalar_field name="DistanceToWall" rank="0">
> > <prescribed>
> > <mesh name="VelocityMesh"></mesh>
> > <value name="WholeMesh">
> > <python>
> > <string_value lines="20" type="code"
> language="python">def val(X,t):&#x0D;&#x0A; xc=0.0 # x at circile center
> &#x0D;&#x0A; yc=0.0 # y at circile center &#x0A; rad=0.03 # radius
> 0.03&#x0A; dep=0.07 # depth 0.07&#x0D;&#x0A;
> val=((X[0]-xc)**2+(X[1]-yc)**2)**0.5 - rad&#x0A;# if more close to bottom
> &#x0D;&#x0A; if val&gt;(dep+X[2]): &#x0A; val=dep+X[2]&#x0A; if
> val&lt;0:&#x0A; val=0&#x0A; &#x0A; return val</string_value>
> > </python>
> > </value>
> > <output></output>
> > <stat></stat>
> > <detectors>
> >
> <exclude_from_detectors></exclude_from_detectors>
> > </detectors>
> > </prescribed>
> > </scalar_field>
> > <C_mu>
> > <real_value rank="0">0.09</real_value>
> > </C_mu>
> > <C_eps_1>
> > <real_value rank="0">1.44</real_value>
> > </C_eps_1>
> > <C_eps_2>
> > <real_value rank="0">1.92</real_value>
> > </C_eps_2>
> > <sigma_k>
> > <real_value rank="0">1</real_value>
> > </sigma_k>
> > <sigma_eps>
> > <real_value rank="0">1.3</real_value>
> > </sigma_eps>
> > <sigma_p>
> > <real_value rank="0">1</real_value>
> > </sigma_p>
> > <time_discretisation>
> > <theta>
> > <real_value rank="0">0.5</real_value>
> > </theta>
> > <source_term_implementation>
> > <production_term>source</production_term>
> > <destruction_term>absorbtion</destruction_term>
> > <buoyancy_term>source</buoyancy_term>
> > </source_term_implementation>
> > </time_discretisation>
> > <mass_terms>
> > <lump_mass></lump_mass>
> > </mass_terms>
> > </k-epsilon>
> > </subgridscale_parameterisations>
> > <scalar_field name="Pressure" rank="0">
> > <prognostic>
> > <mesh name="PressureMesh"></mesh>
> > <spatial_discretisation>
> > <continuous_galerkin>
> >
> <remove_stabilisation_term></remove_stabilisation_term>
> >
> <integrate_continuity_by_parts></integrate_continuity_by_parts>
> > </continuous_galerkin>
> > </spatial_discretisation>
> > <scheme>
> > <poisson_pressure_solution>
> > <string_value lines="1">never</string_value>
> > </poisson_pressure_solution>
> > <use_projection_method></use_projection_method>
> > </scheme>
> > <solver>
> > <iterative_method name="cg"></iterative_method>
> > <preconditioner name="mg">
> > <vertical_lumping></vertical_lumping>
> > </preconditioner>
> > <relative_error>
> > <real_value rank="0">1e-07</real_value>
> > </relative_error>
> > <max_iterations>
> > <integer_value rank="0">3000</integer_value>
> > </max_iterations>
> >
> <never_ignore_solver_failures></never_ignore_solver_failures>
> > <diagnostics>
> > <monitors></monitors>
> > </diagnostics>
> > </solver>
> > <output></output>
> > <stat></stat>
> > <convergence>
> > <include_in_convergence></include_in_convergence>
> > </convergence>
> > <detectors>
> > <exclude_from_detectors></exclude_from_detectors>
> > </detectors>
> > <consistent_interpolation></consistent_interpolation>
> > </prognostic>
> > </scalar_field>
> > <vector_field name="Velocity" rank="1">
> > <prognostic>
> > <mesh name="VelocityMesh"></mesh>
> > <equation name="Boussinesq"></equation>
> > <spatial_discretisation>
> > <discontinuous_galerkin>
> > <viscosity_scheme>
> >
> <compact_discontinuous_galerkin></compact_discontinuous_galerkin>
> > <tensor_form></tensor_form>
> > </viscosity_scheme>
> > <upwind></upwind>
> > <project_velocity_to_continuous>
> > <mesh name="CoordinateMesh"></mesh>
> > </project_velocity_to_continuous>
> > <twice></twice>
> > </discontinuous_galerkin>
> > <real_value rank="0">0</real_value>
> > </spatial_discretisation>
> > <temporal_discretisation>
> > <theta>
> > <real_value rank="0">1</real_value>
> > </theta>
> > <relaxation>
> > <real_value rank="0">1</real_value>
> > </relaxation>
> > <discontinuous_galerkin>
> > <maximum_courant_number_per_subcycle>
> > <real_value rank="0">0.1</real_value>
> > </maximum_courant_number_per_subcycle>
> > </discontinuous_galerkin>
> > </temporal_discretisation>
> > <solver>
> > <iterative_method name="gmres">
> > <restart>
> > <integer_value rank="0">30</integer_value>
> > </restart>
> > </iterative_method>
> > <preconditioner name="sor"></preconditioner>
> > <relative_error>
> > <real_value rank="0">1e-07</real_value>
> > </relative_error>
> > <max_iterations>
> > <integer_value rank="0">10000</integer_value>
> > </max_iterations>
> >
> <never_ignore_solver_failures></never_ignore_solver_failures>
> > <diagnostics>
> > <monitors></monitors>
> > </diagnostics>
> > </solver>
> > <initial_condition name="WholeMesh">
> > <constant>
> > <real_value rank="1" shape="3" dim1="dim">0 0
> 0</real_value>
> > </constant>
> > </initial_condition>
> > <boundary_conditions name="B_drag">
> > <surface_ids>
> > <integer_value rank="1"
> shape="1">308</integer_value>
> > </surface_ids>
> > <type name="drag">
> > <constant>
> > <real_value rank="0">0.0025</real_value>
> > <comment>0.0025</comment>
> > </constant>
> > </type>
> > </boundary_conditions>
> > <boundary_conditions name="T_FreeSurface">
> > <surface_ids>
> > <integer_value rank="1"
> shape="1">307</integer_value>
> > </surface_ids>
> > <type name="free_surface"></type>
> > </boundary_conditions>
> > <boundary_conditions name="P_B_NoNormalFlow">
> > <surface_ids>
> > <integer_value rank="1" shape="2">11
> 308</integer_value>
> > </surface_ids>
> > <type name="no_normal_flow"></type>
> > </boundary_conditions>
> > <boundary_conditions name="W_const_Vel">
> > <surface_ids>
> > <integer_value rank="1"
> shape="1">10</integer_value>
> > </surface_ids>
> > <type name="dirichlet">
> > <apply_weakly></apply_weakly>
> > <align_bc_with_cartesian>
> > <x_component>
> > <constant>
> > <real_value
> rank="0">0.2</real_value>
> > <comment>def val(X,t):&#x0A;
> amp=0.5&#x0A; if (t&lt;10):&#x0A; val=amp*t/10&#x0A; else:&#x0A;
> val=amp&#x0A;&#x0A; return val</comment>
> > </constant>
> > </x_component>
> > </align_bc_with_cartesian>
> > </type>
> > </boundary_conditions>
> > <boundary_conditions name="S_N_FREESLIP">
> > <surface_ids>
> > <integer_value rank="1" shape="2">7
> 9</integer_value>
> > </surface_ids>
> > <type name="dirichlet">
> > <apply_weakly></apply_weakly>
> > <align_bc_with_cartesian>
> > <y_component>
> > <constant>
> > <real_value rank="0">0</real_value>
> > </constant>
> > </y_component>
> > </align_bc_with_cartesian>
> > </type>
> > </boundary_conditions>
> > <tensor_field name="Viscosity" rank="2">
> > <diagnostic>
> > <algorithm name="Internal"
> material_phase_support="multiple"></algorithm>
> > <output></output>
> > <stat>
> > <include_in_stat></include_in_stat>
> > </stat>
> > </diagnostic>
> > </tensor_field>
> > <vertical_stabilization>
> > <implicit_buoyancy></implicit_buoyancy>
> > </vertical_stabilization>
> > <output></output>
> > <stat>
> > <include_in_stat></include_in_stat>
> > <previous_time_step>
> > <exclude_from_stat></exclude_from_stat>
> > </previous_time_step>
> > <nonlinear_field>
> > <exclude_from_stat></exclude_from_stat>
> > </nonlinear_field>
> > </stat>
> > <convergence>
> > <include_in_convergence></include_in_convergence>
> > </convergence>
> > <detectors>
> > <include_in_detectors></include_in_detectors>
> > </detectors>
> > <consistent_interpolation></consistent_interpolation>
> > </prognostic>
> > </vector_field>
> > <scalar_field name="FreeSurface" rank="0">
> > <diagnostic>
> > <algorithm name="Internal"
> material_phase_support="multiple"></algorithm>
> > <mesh name="PressureMesh"></mesh>
> > <output></output>
> > <stat></stat>
> > <convergence>
> > <include_in_convergence></include_in_convergence>
> > </convergence>
> > <detectors>
> > <include_in_detectors></include_in_detectors>
> > </detectors>
> > </diagnostic>
> > </scalar_field>
> > <scalar_field name="DG_CourantNumber" rank="0">
> > <diagnostic>
> > <algorithm name="Internal"
> material_phase_support="multiple"></algorithm>
> > <mesh name="VelocityMesh"></mesh>
> > <output>
> > <exclude_from_vtu></exclude_from_vtu>
> > </output>
> > <stat></stat>
> > <convergence>
> > <include_in_convergence></include_in_convergence>
> > </convergence>
> > <detectors>
> > <include_in_detectors></include_in_detectors>
> > </detectors>
> > </diagnostic>
> > </scalar_field>
> > <vector_field name="BedShearStress" rank="1">
> > <diagnostic>
> > <algorithm name="Internal"
> material_phase_support="multiple"></algorithm>
> > <mesh name="VelocityMesh"></mesh>
> > <density>
> > <real_value rank="0">1000</real_value>
> > </density>
> > <calculation_method>
> > <drag_coefficient>
> > <real_value rank="0">0.0025</real_value>
> > <comment>2.5e-3</comment>
> > </drag_coefficient>
> > </calculation_method>
> > <output></output>
> > <stat>
> > <include_in_stat></include_in_stat>
> > </stat>
> > <detectors>
> > <include_in_detectors></include_in_detectors>
> > </detectors>
> > </diagnostic>
> > </vector_field>
> > <sediment>
> > <scalar_field name="sed1" rank="0">
> > <prognostic>
> > <mesh name="VelocityMesh"></mesh>
> > <spatial_discretisation>
> > <control_volumes>
> > <face_value name="FiniteElement">
> > <limit_face_value>
> > <limiter name="Sweby">
> >
> <project_upwind_value_from_point>
> > <store_upwind_elements>
> >
> > </store_upwind_elements>
> >
> </project_upwind_value_from_point>
> > </limiter>
> > </limit_face_value>
> > </face_value>
> > <diffusion_scheme
> > </control_volumes>
> > <real_value rank="0">0</real_value>
> > </spatial_discretisation>
> > <temporal_discretisation>
> > <theta>
> > <real_value rank="0">0.5</real_value>
> > </theta>
> > <control_volumes>
> > <integer_value
> rank="0">3</integer_value>
> > <limit_theta></limit_theta>
> > </control_volumes>
> > </temporal_discretisation>
> > <solver>
> > <iterative_method name="gmres">
> > <restart>
> > <integer_value
> rank="0">30</integer_value>
> > </restart>
> > </iterative_method>
> > <preconditioner name="sor"></preconditioner>
> > <relative_error>
> > <real_value rank="0">1e-07</real_value>
> > </relative_error>
> > <max_iterations>
> > <integer_value rank="0">2000</integer_value>
> > </max_iterations>
> >
> <never_ignore_solver_failures></never_ignore_solver_failures>
> > <diagnostics>
> > <monitors></monitors>
> > </diagnostics>
> > </solver>
> > <initial_condition name="WholeMesh">
> > <constant>
> > <real_value rank="0">0</real_value>
> > </constant>
> > </initial_condition>
> > <boundary_conditions name="B_sed_re">
> > <surface_ids>
> > <integer_value rank="1"
> shape="1">308</integer_value>
> > </surface_ids>
> > <type name="sediment_reentrainment">
> > <algorithm>Garcia_1991</algorithm>
> > </type>
> > </boundary_conditions>
> > <boundary_conditions name="ZeroFlux_S_N_W_P_T">
> > <surface_ids>
> > <integer_value rank="1" shape="5">7 9 10 11
> 307</integer_value>
> > </surface_ids>
> > <type name="zero_flux"></type>
> > </boundary_conditions>
> > <boundary_conditions name="E_Neum">
> > <surface_ids>
> > <integer_value rank="1"
> shape="1">8</integer_value>
> > </surface_ids>
> > <type name="neumann">
> > <constant>
> > <real_value rank="0">0</real_value>
> > </constant>
> > </type>
> > </boundary_conditions>
> > <tensor_field name="Diffusivity" rank="2">
> > <prescribed>
> > <value name="WholeMesh">
> > <isotropic>
> > <constant>
> > <real_value
> rank="0">1e-10</real_value>
> > </constant>
> > </isotropic>
> > </value>
> > <output></output>
> > </prescribed>
> > </tensor_field>
> > <scalar_field name="SinkingVelocity" rank="0">
> > <diagnostic>
> > <mesh name="VelocityMesh"></mesh>
> > <algorithm name="Internal"
> material_phase_support="multiple"></algorithm>
> > <output></output>
> > <stat></stat>
> > <detectors>
> >
> <include_in_detectors></include_in_detectors>
> > </detectors>
> > </diagnostic>
> > </scalar_field>
> > <output></output>
> > <stat></stat>
> > <convergence>
> >
> <include_in_convergence></include_in_convergence>
> > </convergence>
> > <detectors>
> > <include_in_detectors></include_in_detectors>
> > </detectors>
> >
> >
> <consistent_interpolation></consistent_interpolation>
> > <prognostic>
> > <surface_ids>
> > <integer_value rank="1"
> shape="1">308</integer_value>
> > </surface_ids>
> > <spatial_discretisation>
> > <control_volumes>
> > <face_value name="FiniteElement">
> > <limit_face_value>
> > <limiter name="Sweby">
> >
> <project_upwind_value_from_point>
> >
> <store_upwind_elements>
> >
> >
> </store_upwind_elements>
> >
> </project_upwind_value_from_point>
> > </limiter>
> > </limit_face_value>
> > </face_value>
> > <diffusion_scheme
> > </control_volumes>
> > <real_value rank="0">0</real_value>
> > </spatial_discretisation>
> > <temporal_discretisation>
> > <theta>
> > <real_value
> rank="0">0.5</real_value>
> > </theta>
> > <control_volumes>
> > <integer_value
> rank="0">3</integer_value>
> > <limit_theta></limit_theta>
> > </control_volumes>
> > </temporal_discretisation>
> > <solver>
> > <iterative_method name="gmres">
> > <restart>
> > <integer_value
> rank="0">30</integer_value>
> > </restart>
> > </iterative_method>
> > <preconditioner
> name="sor"></preconditioner>
> > <relative_error>
> > <real_value
> rank="0">1e-07</real_value>
> > </relative_error>
> > <max_iterations>
> > <integer_value
> rank="0">1000</integer_value>
> > </max_iterations>
> >
> <never_ignore_solver_failures></never_ignore_solver_failures>
> > <diagnostics>
> > <monitors></monitors>
> > </diagnostics>
> > </solver>
> > <initial_condition name="WholeMesh">
> > <constant>
> > <real_value
> rank="0">0.04</real_value>
> > </constant>
> > </initial_condition>
> > <output></output>
> > <stat></stat>
> > <convergence>
> >
> <include_in_convergence></include_in_convergence>
> > </convergence>
> > <detectors>
> >
> <include_in_detectors></include_in_detectors>
> > </detectors>
> >
> >
> <consistent_interpolation></consistent_interpolation>
> > </prognostic>
> > </scalar_field>
> > <diagnostic>
> > <output>
> > <exclude_from_vtu></exclude_from_vtu>
> > </output>
> > <stat></stat>
> > <convergence>
> >
> <include_in_convergence></include_in_convergence>
> > </convergence>
> > <detectors>
> >
> <include_in_detectors></include_in_detectors>
> > </detectors>
> >
> > </diagnostic>
> > </scalar_field>
> > <diagnostic>
> > <output></output>
> > <stat></stat>
> > <convergence>
> >
> <include_in_convergence></include_in_convergence>
> > </convergence>
> > <detectors>
> >
> <include_in_detectors></include_in_detectors>
> > </detectors>
> >
> > </diagnostic>
> > </scalar_field>
> > <diagnostic>
> > <output></output>
> > <stat></stat>
> > <convergence>
> >
> <include_in_convergence></include_in_convergence>
> > </convergence>
> > <detectors>
> >
> <include_in_detectors></include_in_detectors>
> > </detectors>
> >
> > </diagnostic>
> > </scalar_field>
> > <scalar_field name="UnhinderedSinkingVelocity"
> rank="0">
> > <prescribed>
> > <mesh name="VelocityMesh"></mesh>
> > <value name="WholeMesh">
> > <constant>
> > <real_value
> rank="0">0.0133</real_value>
> > <comment>0.014</comment>
> > </constant>
> > </value>
> > <output>
> > <exclude_from_vtu></exclude_from_vtu>
> > </output>
> > <stat></stat>
> > <detectors>
> >
> <exclude_from_detectors></exclude_from_detectors>
> > </detectors>
> > </prescribed>
> > </scalar_field>
> > <submerged_specific_gravity>
> > <real_value rank="0">1.69</real_value>
> > <comment>1.65</comment>
> > </submerged_specific_gravity>
> > <diameter>
> > <real_value rank="0">0.00107</real_value>
> > <comment>0.000125</comment>
> > </diameter>
> > <bed_porosity>
> > <real_value rank="0">0.3</real_value>
> > </bed_porosity>
> > <erodability>
> > <real_value rank="0">1</real_value>
> > </erodability>
> > </prognostic>
> > </scalar_field>
> > <scalar_field name="SedimentBedActiveLayerD50" rank="0">
> > <diagnostic>
> > <surface_ids>
> > <integer_value rank="1"
> shape="1">308</integer_value>
> > </surface_ids>
> > <algorithm name="Internal"
> material_phase_support="multiple"></algorithm>
> > <mesh name="VelocityMesh"></mesh>
> > <output>
> > <exclude_from_vtu></exclude_from_vtu>
> > </output>
> > <stat></stat>
> > <convergence>
> >
> <include_in_convergence></include_in_convergence>
> > </convergence>
> > <detectors>
> > <include_in_detectors></include_in_detectors>
> > </detectors>
> >
> > </diagnostic>
> > </scalar_field>
> > <scalar_field name="SedimentBedActiveLayerSigma" rank="0">
> > <diagnostic>
> > <surface_ids>
> > <integer_value rank="1"
> shape="1">308</integer_value>
> > </surface_ids>
> > <algorithm name="Internal"
> material_phase_support="multiple"></algorithm>
> > <mesh name="VelocityMesh"></mesh>
> > <output>
> > <exclude_from_vtu></exclude_from_vtu>
> > </output>
> > <stat></stat>
> > <convergence>
> >
> <include_in_convergence></include_in_convergence>
> > </convergence>
> > <detectors>
> > <include_in_detectors></include_in_detectors>
> > </detectors>
> >
> > </diagnostic>
> > </scalar_field>
> > <tensor_field name="ZeroSedimentConcentrationViscosity"
> rank="2">
> > <prescribed>
> > <mesh name="VelocityMesh"></mesh>
> > <value name="WholeMesh">
> > <isotropic>
> > <constant>
> > <real_value rank="0">0.001</real_value>
> > </constant>
> > </isotropic>
> > </value>
> > <output></output>
> > </prescribed>
> > </tensor_field>
> > </sediment>
> > </material_phase>
> > </fluidity_options>
> >
>
> --
> Dr Jon Hill
> Research Fellow
> AMCG, Earth Science and Engineering
> Imperial College London
> Mob: 07748254812
> Phone: +44(0)2075949321
>
> You received this question notification because you are a member of
> Fluidity Core Team, which is an answer contact for Fluidity.
>

 Revision history for this message liu chin chi (caite8001) said on 2014-01-06: #3

Hi Jon,
When the K-E be turned off, the model would be stable after 15 second.

Hi Sam,
I've tested slip and no slip on the pier. (all used no slip on the bottom)
and Both are blowing up around 9 second.

I'll try to modify the diffusion, viscosity and a higher resolution next.

Liu

 Revision history for this message Samuel Parkinson (s-parkinson11) said on 2014-01-06: #4

Hello Liu,

Can you confirm a few things:

1. When you have no-slip around the pier, you have low-re boundary
conditions on the k and epsilon fields around the pier.
2. When you have free-slip around the pier, you do not have low-re boundary
conditions on the k and epsilon fields around the pier.
2. It is still blowing up around the pier. If so is the source of the
instability at the pier boundary? Can you send some pictures of the
timesteps leading up to the instability for both the no-slip and free-slip
cases?

Thanks,

Sam

On Mon, Jan 6, 2014 at 3:31 AM, liu chin chi <

> Question #241254 on Fluidity changed:
>
>
> liu chin chi is still having a problem:
> Hi Jon,
> When the K-E be turned off, the model would be stable after 15 second.
>
> Hi Sam,
> I've tested slip and no slip on the pier. (all used no slip on the bottom)
> and Both are blowing up around 9 second.
>
> I'll try to modify the diffusion, viscosity and a higher resolution
> next.
>
>
> Liu
>
> --
> You received this question notification because you are a member of
> Fluidity Core Team, which is an answer contact for Fluidity.
>

 Revision history for this message liu chin chi (caite8001) said on 2014-01-08: #5

Hi SamHi Sam,

I make a mistake of using a drag boundary instead of no slip bounary.
I'm re-running the case now and would post the result letter.
Sorry to be confusing.

Liu

 Revision history for this message liu chin chi (caite8001) said on 2014-01-14: #6

Hello Sam,

The model gets stable now.