can i solve a coupled system for velocity and temperature.

Asked by venkatesh

I have 2 equations namely

1. (d^2 - k^2)(d^2-k^2) w = Ra*k^2*t

2. (d^2 - k^2) t = -w

this is the benard problem for fluid heated from below.

or I hv a 6th order equation for velocity alone

1. (d^2 - k^2)^3 w = -Ra*k^2 w

How do I go about it in FENICS..
please help me.. I know Finite Elements but I just read ur example problem but
could u give me a sample coupled code, just for helping me out.

This work will be extended and will be published in one of the major journals. We are looking for a suitable platform to solve.

Kindly help.

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Revision history for this message
Jan Blechta (blechta) said :
#1

On Fri, 19 Apr 2013 11:51:16 -0000
venkatesh <email address hidden> wrote:
> New question #227046 on FEniCS Project:
> https://answers.launchpad.net/fenics/+question/227046
>
> I have 2 equations namely
>
> 1. (d^2 - k^2)(d^2-k^2) w = Ra*k^2*t
>
> 2. (d^2 - k^2) t = -w
>
> this is the benard problem for fluid heated from below.
>
> or I hv a 6th order equation for velocity alone
>
> 1. (d^2 - k^2)^3 w = -Ra*k^2 w
>
> How do I go about it in FENICS..
> please help me.. I know Finite Elements but I just read ur example
> problem but could u give me a sample coupled code, just for helping
> me out.

Yes, you can solve coupled problem in FEniCS. There are plenty of
them in demo dir, e.g. (Navier-)Stokes, Cahn-Hilliard problem

Check biharmonic demo how to solve higher order problems.

Jan

>
> This work will be extended and will be published in one of the major
> journals. We are looking for a suitable platform to solve.
>
> Kindly help.
>
>

Revision history for this message
venkatesh (venkateshgk-j) said :
#2

Hi thanks

I will try it out and let you know if i come across any problem..

by the way, is it possible to use higher order polynomials ?

thank you,
venkatesh

Revision history for this message
Jan Blechta (blechta) said :
#3

On Fri, 19 Apr 2013 19:16:18 -0000
venkatesh <email address hidden> wrote:
> Question #227046 on FEniCS Project changed:
> https://answers.launchpad.net/fenics/+question/227046
>
> Status: Answered => Open
>
> venkatesh is still having a problem:
> Hi thanks
>
> I will try it out and let you know if i come across any problem..
>
> by the way, is it possible to use higher order polynomials ?

Yes. FEniCS supports continuous Galerkin (Lagrange) elements of
arbitrary order. Moreover many other elements are supported.

Jan

>
> thank you,
> venkatesh
>

Revision history for this message
venkatesh (venkateshgk-j) said :
#4

thank you.