[nmangione]

Hello. I tried searching for similar problems, but I don't think I can describe this well enough. I am relatively new to CFD, and this is my first OpenFOAM simulation.

I am attempting to simulate supersonic, pressure-driven flow through a curved de Laval nozzle, as is used for isotope separation. Solving with CentralFoam, supersonic flow develops, and then crashes. Looking at the results, there is an area with an impossible set of temperature values, very high and very low right next to each other (see attached picture). There is no shock here, the velocity and pressure fields are smooth and continuous.

Has anyone found this issue before? Otherwise, am I making any obvious errors? (Boundary conditions, choice of solver, etc.)

Thank you for whatever help you can give me!


Pressure, p

;
    }
    LightOut
    {
        type            zeroGradient;
    }
    HeavyOut
    {
        type            zeroGradient;
    }
    walls
    {
        type            slip;
    }
}

Temperature, T

;

boundaryField
{
    Inlet
    {
        type            fixedValue;
        value           uniform 300;
    }
    LightOut
    {
        type            zeroGradient;
    }
    HeavyOut
    {
        type            zeroGradient;
    }
    walls
    {
        type            slip;
    }
}

velocity, U

boundaryField
{
    Inlet
    {
        type            zeroGradient;
    }
    LightOut
    {
        type            zeroGradient;
    }
    HeavyOut
    {
        type            zeroGradient;
    }
    walls
    {
        type            slip;
    }
}