CFD Online Discussion Forums - dsmcFoam unanswered questions...

Hello together,

I'm making on DSMC with the dsmcFoam solver of OpenFOAM. Trying to understand the DSMC-method and the conditions to do simulations with this method(to simulate geometries in rarefied gases in high altitude to get drag, lift and moment coefficients) there are still some questions in my mind which are not answered yet:

1. mesh: is there a need of solving the boundary layer with y+=1? Are boundary layers needed at all or is the blockMesh around my Geometrie enough?

2. forceCoefficients: how do I get the forceCoefficients with the dsmcFoam-solver? In "normal" cfd with OpenFOAM I get the values with my pressure p, velocity U and reference area/length and so on like e.g in the motorBike tutorial? But how to do this with dsmcFoam? I don't have this values, do I?

3.Is there the possibility to do the simulations with a near-/farfield (a sphere with center in the geometriecenter and a fixed radius instead of an inlet,outlet,walls="windtunnel")? Can I definde the farfield as "flow" like in the dsmcFoam-tutorials?

4. Segmentation fault: after some simulations with dsmcFoam in an modified wedge15Ma5-tutorial I want to reconstruct the case (cause I'm doing parallel simulations) I get the following error message:

Code:

Create time

 

Reconstructing fields for mesh region0

Time = 1e-05

#0  Foam::error::printStack(Foam::Ostream&) in "/opt/OpenFOAM/OpenFOAM-2.2.1/platforms/linux64Gcc48DPOpt/lib/libOpenFOAM.so"

#1  Foam::sigSegv::sigHandler(int) in "/opt/OpenFOAM/OpenFOAM-2.2.1/platforms/linux64Gcc48DPOpt/lib/libOpenFOAM.so"

#2  ?? in "/lib64/libc.so.6"

#3  Foam::objectRegistry::checkOut(Foam::regIOobject&) const in "/opt/OpenFOAM/OpenFOAM-2.2.1/platforms/linux64Gcc48DPOpt/lib/libOpenFOAM.so"

#4  Foam::regIOobject::~regIOobject() in "/opt/OpenFOAM/OpenFOAM-2.2.1/platforms/linux64Gcc48DPOpt/lib/libOpenFOAM.so"

#5  Foam::IOList<int>::~IOList() in "/opt/OpenFOAM/OpenFOAM-2.2.1/platforms/linux64Gcc48DPOpt/lib/libfiniteVolume.so"

#6  Foam::processorMeshes::read() in "/opt/OpenFOAM/OpenFOAM-2.2.1/platforms/linux64Gcc48DPOpt/lib/libreconstruct.so"

#7  Foam::processorMeshes::readUpdate() in "/opt/OpenFOAM/OpenFOAM-2.2.1/platforms/linux64Gcc48DPOpt/lib/libreconstruct.so"

#8  main in "/opt/OpenFOAM/OpenFOAM-2.2.1/platforms/linux64Gcc48DPOpt/bin/reconstructPar"

#9  __libc_start_main in "/lib64/libc.so.6"

#10  Foam::regIOobject::writeObject(Foam::IOstream::streamFormat, Foam::IOstream::versionNumber, Foam::IOstream::compressionType) const in "/opt/OpenFOAM/OpenFOAM-2.2.1/platforms/linux64Gcc48DPOpt/bin/reconstructPar"

Does anybody know whats going wrong and how to avoid this?

I hope there are a few peole who can help me doing my simulations.
Best regards

CFDNewbie147