[WillemvdM]

Hei

Currently I am trying to solve a problem consisting of a compressible gas flow through an orifice. I am using rhoSimpleFoam for this simulation and has been struggling with this solver for weeks now.

My problem definitely does not lie with the relaxation factors as discussed in quite a few threads in this forum because adjusting this only varies when the solution blows up.

I have also tested the simulation with different solvers like rhoPisoFoam etc with no success.

After a thorough scan a my most recent blow-up a realised that it is temperature related. As soon as it reaches 0C it blows up because the thermophysical values can not be computed. The weird thing for me is that the temperature is not suppose to vary to much, but in my simulation is varies consideribly where the velocities are the highest. For all my simulations I have used the following thermoType:

hPsiThermo<pureMixture<constTransport<specieThermo <hConstThermo<perfectGas>

I used this thermophysical model because it was the only one that seemed to work without errors. When I try the ePsiThermo model as follows it gives the error as displayed below:

ePsiThermo<pureMixture<constTransport<specieThermo <eConstThermo<perfectGas>>>>>;

------------------------------------------------------------------------------------------
Not implemented#0 Foam::error:rintStack(Foam::Ostream&) in "/home/bernarde/OpenFOAM/OpenFOAM-1.6/lib/linux64GccDPOpt/libOpenFOAM.so"
#1 Foam::error::abort() in "/home/bernarde/OpenFOAM/OpenFOAM-1.6/lib/linux64GccDPOpt/libOpenFOAM.so"
#2 Foam::basicThermo::h() in "/home/bernarde/OpenFOAM/OpenFOAM-1.6/lib/linux64GccDPOpt/libbasicThermophysicalModels.so"
#3 main in "/home/bernarde/OpenFOAM/OpenFOAM-1.6/applications/bin/linux64GccDPOpt/rhoSimpleFoam"
#4 __libc_start_main in "/lib64/libc.so.6"
#5 _start at /usr/src/packages/BUILD/glibc-2.9/csu/../sysdeps/x86_64/elf/start.S:116


From function basicThermo::h()
in file basicThermo/basicThermo.C at line 260.


At this point I am really stuck and would appreciate any advice and help with this problem

Thanks
Willem
OpenFoam 1.6
OpenSuse 11.1

[WillemvdM]

It seems like changing my inlet conditions to 'n pressureInletVelocity helped with stability. It still have to nurture my relaxation factors.