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[momentumPredictor] Frozen velocity field

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Old   October 10, 2023, 08:39
Post [momentumPredictor] Frozen velocity field
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Dasha
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Hello everyone,

Can someone tell me how to turn off the equations for the momentum for "foamMultiRun"?


I calculated the pre-initiated field of velocities and pressures. Now I want to calculate my case with only heat transfer. I turned off the flow equations in fvSolution. When I start running the case, the velocity are not calculated in residuals, but the velocity field still changes.

Please someone tell me what could be the problem?

fvSolution:
Code:
PIMPLE
{
    flow off;
    momentumPredictor off;
    nOuterCorrectors 30;
    nCorrectors     1;
    nNonOrthogonalCorrectors 0; 
...
physicalProperties:
Code:
thermoType
{
    type            heRhoThermo;
    mixture         pureMixture;
    transport       const;
    thermo          eConst;
    equationOfState rPolynomial;
    specie          specie;
    energy          sensibleInternalEnergy;
}

mixture
{
    specie
    {
        molWeight       18.015;
    }
    equationOfState
    {
        rho0            1000;
        T0              278;
        //beta            2e-04;
        C (0.001278 -2.1055e-06 3.9689e-09 4.3772e-13 -2.0225e-16);
    }
from log file:
Code:
wedge0_rotated diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
wedge0_rotated DILUPBiCGStab:  Solving for e, Initial residual = 0.000680102566017, Final residual = 5.34837357105e-05, No Iterations 1
wedge0_rotated DICPCG:  Solving for p_rgh, Initial residual = 0.00296039703522, Final residual = 9.69628888453e-09, No Iterations 595
wedge0_rotated diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
wedge0_rotated time step continuity errors : sum local = 1.40253056235e-10, global = -7.49192173107e-13, cumulative = -8.68144446708e-09
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Old   November 6, 2023, 08:26
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Hi, make a minIter 0 for fluid in fvSolution, except for pressure (but I'm not sure)
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Old   November 15, 2023, 05:56
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Dasha
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After testing different configurations, I would like to share my observations and conclusions:

The problem was in the equations of state. I considered a compressible fluid in my case, which is why the velocity field could not remain the same as in the case of an incompressible fluid.

So I came to the conclusion that we cannot simultaneously consider a compressible fluid and an unchanging field of velocities and pressures.

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