How to set the outlet boundary condition which has two direction.

kawinsa · July 4, 2019, 06:01

Hi OpenFoamers,
I am new in openFoam and when I try to make a model myself, I found that the boundary conditions can not satisfy the continious situation.
4.PNG
In this simple model, the inlet is v=0.1m/s p=zerogradient.
But when it comes to outlet, I tried to use freestream conditions but the flux changes every time and I am not able to calculate it.
I just do not want to calculate the outlet BC.
How should I set the boundary condition of outlet.....

Thanks in advance for any possible advices!

Chen

yambanshee · July 9, 2019, 03:47

Without knowing the details of what you are trying to simulate, or the solver you are using, it's hard to give advice on boundary conditions.
For a simple inlet-outlet simulation, p is generally set as a fixed value (0 in incompressible solver, and 101325 in a compressible solver) and U set as zero gradient.

July 4, 2019, 06:01	How to set the outlet boundary condition which has two direction.	#1
kawinsa New Member Yu Chen Join Date: Feb 2019 Posts: 3 Rep Power: 7	Hi OpenFoamers, I am new in openFoam and when I try to make a model myself, I found that the boundary conditions can not satisfy the continious situation. 4.PNG In this simple model, the inlet is v=0.1m/s p=zerogradient. But when it comes to outlet, I tried to use freestream conditions but the flux changes every time and I am not able to calculate it. I just do not want to calculate the outlet BC. How should I set the boundary condition of outlet..... Thanks in advance for any possible advices! Chen

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July 9, 2019, 03:47		#2
yambanshee Senior Member Zander Meiring Join Date: Jul 2018 Posts: 125 Rep Power: 7	Without knowing the details of what you are trying to simulate, or the solver you are using, it's hard to give advice on boundary conditions. For a simple inlet-outlet simulation, p is generally set as a fixed value (0 in incompressible solver, and 101325 in a compressible solver) and U set as zero gradient.