[scott]

Hi there,

I'm running the following command after a simulation to get the total pressure field around my geometry.

postProcess -func "totalPressureIncompressible(p,U)"

The Total pressure in the freestream always appears to be greater than what it should be based on the nu value used, which equates to a density of 1.184. It always seems to result in a density of 1.2.

I've tested with different velocities and the corresponding total pressure in the freestream always comes back to 1.2, once you recalculate density based on the new total pressure value.

I've also tested with random values of nu, and it does not affect the freestream total pressure, again, we always get 1.2, but the total pressure value doesn't change, so it is not actually dependent on nu.

It appears that it is using the following equation fro freestream total pressure 0.5 *density*velocity^2 = 0.5*1.2*U^2. My problem is, I don't want it to use 1.2 as a default, I just can't work out how to change it!

Can anyone confirm that this is the intent? I've tried setting rho an rhoInf to 1.184 in many places so far with no apparent change to the result.

For completeness, I am running this command in OpenFOAM v1706 Windows10.

Once this command is executed, the freestream pressure can be seen in /0/total(p) based on initial conditions. It also is apparent in paraview.

Thanks for your time!

Note: I am using simpleFoam, and I know that the density is not used in the solve calculations, and that to get the correct pressure values I need to multiply by density due to the way OpenFOAM calculates. As part of the type of work we do, we typically use Total Pressure as an output hence I'm trying to work out how to get the correct output. I guess I could scale the field as I know how far out it is, but there has to be somewhere that this 1.2 value is being pulled from, and I'd like to modify it if anyone can help.