# pressure in interFoam

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 August 8, 2015, 14:23 pressure in interFoam #1 Member   Join Date: Aug 2011 Posts: 81 Rep Power: 6 Hello together, I am confused at the moment. iinterFoam writes a p and a p_rgh - file in the time-folder. What is p? Total pressure or static pressure? How can I calculate the total pressure? Thanks for your help Last edited by idefix; August 8, 2015 at 15:55.

 August 8, 2015, 18:14 #2 Senior Member   anonymous Join Date: Aug 2014 Posts: 182 Rep Power: 3 p is the static pressure. In interfoam: In non-multiphase incompressible solvers: Last edited by ssss; August 9, 2015 at 04:45.

 August 9, 2015, 01:13 #3 Member   Join Date: Aug 2011 Posts: 81 Rep Power: 6 Thanks for your explanation. But are you sure that p is divided by the density? The dimension given in the p-file are: dimensions [1 -1 -2 0 0 0 0]

 August 9, 2015, 01:32 #4 Senior Member   anonymous Join Date: Aug 2014 Posts: 182 Rep Power: 3 Yes you are right, I was thinking about simpleFoam and other solvers I will edit my post

 August 9, 2015, 01:52 #5 Senior Member     Khamlaj Join Date: Nov 2010 Location: United States Posts: 138 Rep Power: 6 I have quick question about simpleFoam. I have made a mesh that fits an inviscid case, but the issue how can I use simpleFoam as an inviscid solver. Have you guys used simpleFoam before? Thanks in advance, Tareq

August 9, 2015, 03:23
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Quote:
 Originally Posted by ssss p is the static pressure. p_rgh is p-vec(g) dot (h)
As far as I understood it should be
p_rgh = p-vec(g) dot (h) dot (rho)

Am I right, that I can calculate the total pressure in the following way:

p_tot = p + 0.5 * (mag(U))^2 rho ?

August 9, 2015, 03:25
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Quote:
 Originally Posted by tareqkh I have quick question about simpleFoam. I have made a mesh that fits an inviscid case, but the issue how can I use simpleFoam as an inviscid solver. Have you guys used simpleFoam before? Thanks in advance, Tareq
It would be a kind of "cheating" but setting the viscosity in the transportProperties-file to a very small value?

 August 9, 2015, 03:31 #8 Senior Member     Khamlaj Join Date: Nov 2010 Location: United States Posts: 138 Rep Power: 6 Hello, Thank you for you kind response. I have tried to set up the viscosity almost to zero, but I am not getting a good convergence history. Any idea...? Sorry to bring this question to your question that you are already asked. Best, Tareq

 August 9, 2015, 04:25 #9 Member   Join Date: Aug 2011 Posts: 81 Rep Power: 6 do you have a good convergence when you use viscosity (much greater than zero)?

 August 9, 2015, 04:27 #10 Senior Member     Khamlaj Join Date: Nov 2010 Location: United States Posts: 138 Rep Power: 6 Good question. No, I have not obtained a good convergence history in both cases. Best, Tareq

 August 9, 2015, 04:29 #11 Member   Join Date: Aug 2011 Posts: 81 Rep Power: 6 maybe check your boundary condition first and then turn off the viscosity

 August 9, 2015, 05:22 #12 Senior Member     Khamlaj Join Date: Nov 2010 Location: United States Posts: 138 Rep Power: 6 I am using boundary conditions that I used in one of my old cases since I obtained excellent results. So, I don't think that the problem of is from boundary conditions. Best, Tareq

 August 9, 2015, 07:30 #13 Member   Join Date: Aug 2011 Posts: 81 Rep Power: 6 and where is the difference between the old and new case (if not the boundary conditions)?

August 9, 2015, 22:37
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Khamlaj
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Here are pictures from the mesh and convergence history for the inviscid case. I am guessing this might be the problem.
Attached Images
 Mesh.jpg (98.2 KB, 17 views) History.jpg (35.2 KB, 14 views)

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