Boundary Condition for pressure and velocity

mecman · May 3, 2014, 02:20

Hi everybody
I have question about boundary condition setup in my test case. I am dealing with a case which is totally surrounded by walls all over the boundaries. I am using buoyant pressure and zero gradient boundary conditions for pressure equation. Furthermore, no-slip boundary condition is applied on the walls. Setting the case up in this manner, leads to an unexpected increase in the velocity of one corner which is the result of wrong pressure distribution at the same time. However, if I set zero pressure at one of the boundaries this problem does not occur.
I have also tested the exact same case with interFoam solver using buoyant pressure and zero gradient boundary conditions for pressure equation (Original OpenFOAM solver without any modification). In this case, everything is O.K.
I am guessing that the source terms in the pressure equation are responsible for this error. Would you please kindly provide your comments about this problem?
Best wishes

Artur · May 7, 2014, 17:51

Hi,

I'm afraid a bit more detail is required for anyone to be able to help you.

Please have a look at this thread in order to get an idea of what may be required:

http://www.cfd-online.com/Forums/ope...-get-help.html

Peace,

A

May 3, 2014, 02:20	Boundary Condition for pressure and velocity	#1
mecman Member Mohammad Bahreini Join Date: Dec 2012 Posts: 36 Rep Power: 14	Hi everybody I have question about boundary condition setup in my test case. I am dealing with a case which is totally surrounded by walls all over the boundaries. I am using buoyant pressure and zero gradient boundary conditions for pressure equation. Furthermore, no-slip boundary condition is applied on the walls. Setting the case up in this manner, leads to an unexpected increase in the velocity of one corner which is the result of wrong pressure distribution at the same time. However, if I set zero pressure at one of the boundaries this problem does not occur. I have also tested the exact same case with interFoam solver using buoyant pressure and zero gradient boundary conditions for pressure equation (Original OpenFOAM solver without any modification). In this case, everything is O.K. I am guessing that the source terms in the pressure equation are responsible for this error. Would you please kindly provide your comments about this problem? Best wishes

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May 7, 2014, 17:51		#2
Artur Senior Member Artur Join Date: May 2013 Location: Southampton, UK Posts: 372 Rep Power: 20	Hi, I'm afraid a bit more detail is required for anyone to be able to help you. Please have a look at this thread in order to get an idea of what may be required: http://www.cfd-online.com/Forums/ope...-get-help.html Peace, A