# Pressure boundary condition

 Register Blogs Members List Search Today's Posts Mark Forums Read

 January 20, 2006, 12:01 Pressure boundary condition #1 B. R. Guirguis Guest   Posts: n/a how can i impose a pressure boundary condition when i'm using onservation variables

 January 20, 2006, 12:49 Re: Pressure boundary condition #2 hurricane Guest   Posts: n/a What do u mean by conservation variables? And what kind of flows are u trying to simulate : incompressible or compressible....

 January 20, 2006, 22:52 Re: Pressure boundary condition #3 versi Guest   Posts: n/a Conservative variables are rho, rho*U, rho*V, and \rho E, which are often used as dependent variables to be solved for compressible flows and imply quantity per unit volume. The boundary contidions state their own, irrespetive of conservative or not. Therefore you can use pressure or temperature or velocity or other BC conditions, which may appear in a BC specification.

 January 21, 2006, 02:58 Re: Pressure boundary condition #4 B. R. Guirguis Guest   Posts: n/a yes your definition of the conservation variables are true, sir, but i still don't know how to impose this boundary condition. NOTE: I'm using Finite Element techniques!!!

 January 21, 2006, 06:44 Re: Pressure boundary condition #5 Alan Guest   Posts: n/a Hi Guirguis, the theory of setting boundary conditions is a complex subject and therefore I cannot give any recipe out of my head. Anyway, I assume you know that prescribing pressure is the correct physical boundary condition. In Hirsch "Numerical Computation of Internal and External Flows" Vol. 2 you can find in Chapter 19 a in-depth discussion on how to set boundary conditions. In particular, Hirsch discribes how to transform boundary conditions given in one set of variables (e.g. primitive vars) into another set of variables (e.g. conservative). The only drawback of the sited reference is that it deals with Euler equations. An extension to Navier-Stokes is given in T. Poinsot and S. Lele. "Boundary conditions for direct simulations of compressible viscous flows." Journal of Computational Physics, vol.101(1):104-129 Hope that helps. Have fun, Alan

 January 25, 2006, 10:00 Re: Pressure boundary condition #6 B. R. Guirguis Guest   Posts: n/a Thank you Alan for your help. I solved my problem with home made technique. BUT it was very useful when I went to the library and took a look on Hirsch. It is an excellent book for finite difference techniques. Also I recommend Chung, T. J. "Computational Fluid Dynamics". This book is ann excellent one too. It covers finite difference, finite element, and finite volume all with semi equal depth. I hope everyone have fun with CFD. BYE

 Thread Tools Display Modes Linear Mode

 Posting Rules You may not post new threads You may not post replies You may not post attachments You may not edit your posts BB code is On Smilies are On [IMG] code is On HTML code is OffTrackbacks are On Pingbacks are On Refbacks are On Forum Rules

 Similar Threads Thread Thread Starter Forum Replies Last Post Saturn CFX 48 October 25, 2017 06:07 peob OpenFOAM Running, Solving & CFD 3 February 3, 2017 11:54 C-H Kuo Main CFD Forum 18 September 16, 2016 03:19 Attesz CFX 7 January 5, 2013 04:32 abishek FLUENT 1 July 28, 2008 08:14

All times are GMT -4. The time now is 20:37.