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Boussinesq equation of state combined with polynomial viscosity

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Old   April 19, 2018, 06:02
Default Boussinesq equation of state combined with polynomial viscosity
  #1
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Tomas Denk
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Hi,

I'd like to solve a case where fluid density and viscosity depend on temperature. There are also some walls so I use chtMultiRegionSimpleFoam application.

When I set up thermophysical properties of the fluid like this:
Code:
thermoType
{
    type            heRhoThermo;
    mixture         pureMixture;
    transport       polynomial;
    thermo          hPolynomial;
    equationOfState Boussinesq;
    specie          specie;
    energy          sensibleEnthalpy;
}
I get FOAM FATAL ERROR: Unknown rhoTherm type, followed by listing of valid combinations. I can either use combination sutherland-janaf-Boussineq or polynomial-hPolynomial-icoPolynomial (for transport-thermo-equasionOfState respectively), however, I'd prefer not to.

Naive attempt to add another valid combination by adding
Code:
makeThermos
(
    rhoThermo,
    heRhoThermo,
    pureMixture,
    polynomialTransport,
    sensibleEnthalpy,
    hPolynomialThermo,
    Boussinesq,
    specie
);
to $FOAM_SRC/thermophysicalModels/basic/rhoThermo/rhoThermos.C did not help. Can someone explain why?

Is there a way to use combination of polynomial mu and Cp along with Boussinesq approximation?
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Old   October 29, 2020, 08:41
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Hi.

Did you find a proper solution to your problem?
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Old   October 29, 2020, 15:25
Default Re: polynomial
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Charles
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You can use polynomial.
Code:
thermoType
{
    type            heRhoThermo;
    mixture         pureMixture;
    transport       polynomial;
    thermo          hPolynomial;
    equationOfState icoPolynomial;
    specie          specie;
    energy          sensibleInternalEnergy;
}
For the equation of state, Boussinesq equation can be approximated by a polynomial. See Peric's book on page 15,
\rho = (\rho_0 + \rho_0 \beta T_0) - \rho_0 \beta T
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Old   October 30, 2020, 04:16
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Tomas Denk
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Interesting, thanks for this tip, I haven't thought of that.
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