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alex September 30, 2001 08:52

fixed pressure
does anyone know how to set fixed pressure boundary conditions on a cube [Nx, Ny, Nz]. The pressure should be 1e+05. How to solve for the pressure inside the cube? Please help, Alex

Kike October 1, 2001 11:20

Re: fixed pressure
Dear Alex

Could you comment what have you understood from ther visit you should did to POILS information system (

Here I give you some hints (a) Encyclopaedia (b) COVAL (c) Solution Procedure or SOLUTN.



alex October 3, 2001 09:18

Re: fixed pressure
kike, kind thanks for your useful hints. alex

David Glynn October 4, 2001 13:01

Re: fixed pressure
Do you mean that you want to solve inside the cube, with fixed pressure boundaries on all the faces? If so, simply define an OUTLET object for each face in VR. (Remember, OUTLET really means fixed pressure, the flow can be inflow or outflow). But you should set the pressure value to zero (i.e. it is a relative pressure), and the reference pressure to 1E5.

alex October 5, 2001 11:53

Re: fixed pressure
dear david, thank you for you answer and your help. I was thinking to do so but wans't completely sure. i set press0 to be 1e5 and used different patch names for each side of the cube. do the patch names have to be OUTLET or you can speacify any name and after that just use east, west etc. If you can answer this question, i would be very greateful to you. Thank you again. Alex

David Glynn October 5, 2001 12:38

Re: fixed pressure
The patch names have to be different, any names will do.

If you have not already done so, I suggest you read the lecture on "boundary conditions" in "general lectures for version 2" under "How to Learn" in Polis. This tells you all the details.

Alternatively - and much simpler!!! - just use VR, define a zero-thickness object on each of the boundary faces, and define each one as an OUTLET object.

Hope this is helpful.


alex October 6, 2001 11:29

Re: fixed pressure
thank you davis, i think i think it is working now. best regards from me. alex

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