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-   -   Solid cells on symplane boundaries (http://www.cfd-online.com/Forums/cd-adapco/55403-solid-cells-symplane-boundaries.html)

samu May 27, 2006 10:39

Solid cells on symplane boundaries
 
Hello experts,

I want to run an axi-summetric problem, so i use symmetry boundaries.

On the symmetry boundaries there are fluid, but also solid cells. The latter causes the following problem when i try to write the geom file :

NO CELL FOUND FOR BOUNDARY

The missing cells are the solid cells of the symplane boundary.

Does anybody know what's the problem and propose any solution?

Thanks in advance, samu

TG May 27, 2006 17:08

Re: Solid cells on symplane boundaries
 
Are you sure that you have turned on conjugate heat transfer? If it is not on, then pro-STAR ignores solid cells which would probably trigger that message (it sees a boundary but it doesn't see any connected cell).

samu May 28, 2006 07:36

Re: Solid cells on symplane boundaries
 
Thanks for your answer, by turning Conjugate Heat Transfer on, the problem has been solved.

However, i want to simulate an isothermal problem.

Is enough to just set the same temperature in Initialization (let's say T=573K) of Material 1 (Fluid) and Material 2(Solid), or i have to make more changes as well?

samu

Ralphie May 29, 2006 05:01

Re: Solid cells on symplane boundaries
 
Why do you want to include solid cells in an isothermal simulation? What do you expect Star-CD to calculate?

samu May 29, 2006 05:24

Re: Solid cells on symplane boundaries
 
I just want to use solid cells as an adiabatic and impermeable wall, instead of baffles.

Know the next logical question is : "Why you dont use baffles instead?"

Thats because i want the wall to have thickness.

samu


Ralphie May 29, 2006 05:32

Re: Solid cells on symplane boundaries
 
You don't even have to use baffles...

You can just define the appropriate boundary conditions on your walls (there won't be an option to make them adiabatic if you are running an isothermal case).

Do want the thickness of your walls just for post-processing/displaying your results?

samu May 29, 2006 08:37

Re: Solid cells on symplane boundaries
 
I am simulating a foam catalytic converter, that contains a metalic tube fulled with holes, on which is the catalytic foam supported.

So to make a more realistic simulation (and to take more reliable results about pressure drop and velocities) i considered as a better option to use solid cells for the tube, instead of the baffles i was using until now.

However, i don't have to perform thermal calculations.

If you could propose me a better approach for the simulation of the metalic tube, you 'll be welcome.

Thanks for your interest

samu


Ralphie May 29, 2006 10:07

Re: Solid cells on symplane boundaries
 
The point is that if you perform isothermal calculations, the code will ignore solid cells because they do not have any influence on your fluid flow. All you have to define is the wall boundary condition.


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