[shurikStP85]

Hello everyone,
I'm trying to calculate the mixing between NaCl-solution and pure water. The concentration of NaCl should be modeled by a modified bouyantPimpleFoam-Solver. The fluid properties vary strongly with the concentration comparable to the temperature dependent fluid properties of water. The idea is to substitute the temperature dependent properties (polynoms) with concentration dependent properties (polynoms). But for the concentration transport the enthalpy equation should be used.

Modified enthalpy equation.
fvm::ddt(rho,he)+fvm::div(phi,he)-fvm::laplacian(turbulence->alphaEff(),he)==fvOptions(rho,he)

Thermal properties: cp(T),rho(T),k(T),mu(T) (as polynoms).

If I interpreted it right, alphaEff() = k(T)/c_p(T)+mu_t/Pr_t and h=cp*(T-Tref) when (cp=1).
Than from a mathematical point of view k(T)/c_p(T) can be substituted by rho(T)*D (D=constant diffusion coefficient).

The fluid properties are fitted over the mass weight in %+Tref -> Coefficients.

So the thermophysical-file looks like
Thermotype
{ type heRhoThermo; mixture pureMixture; transport polynomial; thermo hPolynomial; equationOfState icoPolynomial, specie specie; energy sensibleEnthalpy;}
Dpdt off;
Mixture {
{ specie {nMoles 1; molWeight 1}
EquationOfState {rhoCoeffs<8> (1267 -8.742 0.02631 0 0 0 0 0);}
Thermodynamics {Hf=0; Sf=0; CpCoeffs<8> (1 0 0 0 0 0 0 0);}
Transport {muCoeffs<8> (0.09565 -0.0006425 1.09e-06 0 0 0 0 0); kappaCoeffs<8> (1267e-9 -8.742e-9 0.02631e-9 0 0 0 0 0);
So the modified solver is running and the fluid properties look plausible but I’m not sure about the turbulence.

I would be grateful to read some opinions.
Thanks