[Alpha001]

Hello,

Here are my details about my system:
Kubuntu 18.04LTS
OpenFoam v7

Case set up:
I am trying to run a LES-VOF simulation for waterjet in an AWJC Nozzle, where the water jet velocity is 300m/s.
The phases are air and water.
I have successfully run a simulation with interFoam (incompressible case).

I want to run a compressible simulation for the same case set up.
I took the thermophysicalProperties, thermophysicalProperties.air and thermophysicalProperties.water from sloshing tank tutorial case.
I replicated p_rgh to p and added a T file sine there was none in the interFoam case.

The T file is as follows:

FoamFile
{
    version     2.0;
    format      ascii;
    class       volScalarField;
    object      T;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [0 0 0 1 0 0 0];

internalField   uniform 300;

boundaryField
{
    wall
    {
        type             fixedValue;
        value            uniform 300;
    }

    inlet
    {
        type             fixedValue;
        value            uniform 300;
    }
    
    inlet2
    {
        type             fixedValue;
        value            uniform 300;
    }
    
    inlet3
    {
        type             fixedValue;
        value            uniform 300;
    }
    
    outlet
    {
        type             fixedValue;
        value            uniform 300;
    }
}

By reading a similar case , I think the issue is with the boundary condition set-up of the Temperature field, since I don't have any experience with any compressible cases.

Here is the error:

/*---------------------------------------------------------------------------*\
  =========                 |
  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   \\    /   O peration     | Website:  https://openfoam.org
    \\  /    A nd           | Version:  7
     \\/     M anipulation  |
\*---------------------------------------------------------------------------*/
Build  : 7-1ff648926f77
Exec   : compressibleInterFoam
Date   : Aug 26 2020
Time   : 11:35:03
Host   : "XDEM-laptop"
PID    : 17318
I/O    : uncollated
Case   : /home/prasad/01_PhD/3_Tutorials/3_trials/0_Nozzle_OF/Turb_1_300ms-1_compressibleInterFoam
nProcs : 1
sigFpe : Enabling floating point exception trapping (FOAM_SIGFPE).
fileModificationChecking : Monitoring run-time modified files using timeStampMaster (fileModificationSkew 10)
allowSystemOperations : Allowing user-supplied system call operations

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
Create time

Create mesh for time = 0

Selecting dynamicFvMesh staticFvMesh

PIMPLE: No convergence criteria found


PIMPLE: Operating solver in transient mode with 1 outer corrector
PIMPLE: Operating solver in PISO mode


Reading field p_rgh

Reading field U

Reading/calculating face flux field phi

Constructing twoPhaseMixtureThermo

Selecting thermodynamics package 
{
    type            heRhoThermo;
    mixture         pureMixture;
    transport       const;
    thermo          eConst;
    equationOfState perfectFluid;
    specie          specie;
    energy          sensibleInternalEnergy;
}

Selecting thermodynamics package 
{
    type            heRhoThermo;
    mixture         pureMixture;
    transport       const;
    thermo          hConst;
    equationOfState perfectGas;
    specie          specie;
    energy          sensibleInternalEnergy;
}

#0  Foam::error::printStack(Foam::Ostream&) at ??:?
#1  Foam::sigFpe::sigHandler(int) at ??:?
#2  ? in "/lib/x86_64-linux-gnu/libc.so.6"
#3  Foam::heThermo<Foam::rhoThermo, Foam::pureMixture<Foam::constTransport<Foam::species::thermo<Foam::hConstThermo<Foam::perfectGas<Foam::specie> >, Foam::sensibleInternalEnergy> > > >::heThermo(Foam::fvMesh const&, Foam::word const&) at ??:?
#4  Foam::rhoThermo::addfvMeshConstructorToTable<Foam::heRhoThermo<Foam::rhoThermo, Foam::pureMixture<Foam::constTransport<Foam::species::thermo<Foam::hConstThermo<Foam::perfectGas<Foam::specie> >, Foam::sensibleInternalEnergy> > > > >::New(Foam::fvMesh const&, Foam::word const&) at ??:?
#5  Foam::autoPtr<Foam::rhoThermo> Foam::basicThermo::New<Foam::rhoThermo>(Foam::fvMesh const&, Foam::word const&) at ??:?
#6  Foam::rhoThermo::New(Foam::fvMesh const&, Foam::word const&) at ??:?
#7  Foam::twoPhaseMixtureThermo::twoPhaseMixtureThermo(Foam::GeometricField<Foam::Vector<double>, Foam::fvPatchField, Foam::volMesh> const&, Foam::GeometricField<double, Foam::fvsPatchField, Foam::surfaceMesh> const&) at ??:?
#8  ? in "/opt/openfoam7/platforms/linux64GccDPInt32Opt/bin/compressibleInterFoam"
#9  __libc_start_main in "/lib/x86_64-linux-gnu/libc.so.6"
#10  ? in "/opt/openfoam7/platforms/linux64GccDPInt32Opt/bin/compressibleInterFoam"
Floating point exception (core dumped)

I need suggestions. Please let me know if I should share anything else.

Thank you in advance.

[snak]

Hi,


Is your p file physically correct?



incompressible solvers use relative pressure.
compressible solvers use absolute pressure because the state of fluid is based on the pressure etc.


I am not sure what your picture means... It shows negative pressure, isn't it?

[Bloerb]

Try this:

     outlet
    {
    type             zeroGradient;
    value            uniform 300;
    }

Prescribing the temperatue at the outlet seems unnecessary for your objective and increases numerical instability since with inflow and outflow temperature prescribed there is no room for numerical error.