Backward Facing Step

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

 May 30, 2012, 09:40 Backward Facing Step #1 New Member   L.M. Yang Join Date: Oct 2011 Posts: 9 Rep Power: 8 Hi, guys I am simulating the laminar backward facing step with a 2D incompressible CFD code. Could any of you direct me how to set the inlet and outlet boundary conditions? The velocity profile of inlet boundary have been obtained. However, how do I set the pressure of inlet boundary and pressure and velocity of outlet boundary? With kind regards, Laman Yang

 May 30, 2012, 14:39 #2 Member   Peter Galimutti Join Date: May 2012 Posts: 37 Rep Power: 7 Since you already have a velocity profile, you do not need to set any inlet pressure. Pressure is implicit calculation based on velocity. At the outlet 1 atm pressure can be given! BTW, you said you are using code, so giving boundary conditions is specific to that code and check the manual on how to define b.cs

May 30, 2012, 21:03
#3
New Member

L.M. Yang
Join Date: Oct 2011
Posts: 9
Rep Power: 8
Quote:
 Originally Posted by p.galimutti Since you already have a velocity profile, you do not need to set any inlet pressure. Pressure is implicit calculation based on velocity. At the outlet 1 atm pressure can be given! BTW, you said you are using code, so giving boundary conditions is specific to that code and check the manual on how to define b.cs
Hi, Peter
Thanks for you comments. Actually, the code is developed by myself. In this code, the conventional Navier-Stokes equation is solved rather than its incompressible forms (e.g. governing equation for artificial compressibility method and pre-conditioning method). So, in the inlet boundary there are three characteristics enter and one leaves the physical domain, i.e., the pressure in b.c need to extrapolate from the interior of the physical domain. My confusion is how to calculate the pressure. Similarly, the velocities in outlet b.c need to extrapolate from the interior of the physical domain. How could I evaluate the velocities in outlet b.c.

regards

 May 31, 2012, 08:35 #4 Senior Member   Andrew Join Date: Mar 2009 Location: Washington, DC Posts: 195 Rep Power: 10 have you thought about transforming your equations to the streamline-vorticity equations? that way your pressure term drops out, and the bc's are pretty straight forward.

 May 31, 2012, 10:29 #5 New Member   L.M. Yang Join Date: Oct 2011 Posts: 9 Rep Power: 8 Thanks for your advice. However, the flux solver in my code is developed by lattice Boltzmann method and the governing equation is the conventional Navier-Stokes equation. It is harder to transform the governing equation.

 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 xiuying OpenFOAM Running, Solving & CFD 8 August 27, 2013 15:33 Fluids Main CFD Forum 7 December 4, 2012 12:28 bookie56 OpenFOAM Installation 8 August 13, 2011 04:03 msrinath80 OpenFOAM Running, Solving & CFD 9 July 22, 2007 02:58 liugx212 OpenFOAM Running, Solving & CFD 3 January 4, 2006 19:07

All times are GMT -4. The time now is 01:47.