[kooki_13]

Dear fomers


While implementing LES of turbulent jet flow, I have come across with:


fvm::ddt(alpha, rho, k_)
+ fvm::div(alphaRhoPhi, k_)
- fvm::laplacian(alpha*rho*DkEff(), k_)
==
alpha*rho*G
- fvm::SuSp((2.0/3.0)*alpha*rho*divU, k_)
- fvm::Sp(Ce(D, KK)*alpha*rho*sqrt(k_)/this->delta(), k_)
+ kSource()
+ fvModels.source(alpha, rho, k_)


and I cannot fully understand that.


Could anyone kindly explain:
1- What is alpha and alphaRhoPhi?
2- What does the term alpha*rho*G calculate? is it production?
3- Does KK represent ksgs?


I have read the related reference https://arc.aiaa.org/doi/10.2514/6.1995-356; but unfortunately I could not follow the code.


Kind Regards
Koukab

[LuckyTran]

alpha is the phase fraction for multi-phase scenarios
G is production
k_ is the sgs k. KK comes from the dynamic procedure for Ce

[kooki_13]

Originally Posted by LuckyTran

alpha is the phase fraction for multi-phase scenarios
G is production
k_ is the sgs k. KK comes from the dynamic procedure for Ce

Thank you Lucky!
But I cannot understand that how does it (G) appear when in the Ref. paper it was not considered?
Still alphaRhoPhi remained unclear...

[LuckyTran]

The production term is the tau *u term. I don't have the paper in front of me but there's no way it isn't in there.

alphaRhoPhi is the convective mass flux for a multi-phase mixture. Phi is the convective flux for simple mixtures. Get used to seeing it.... It's everywhere.

[kooki_13]

Originally Posted by LuckyTran

The production term is the tau *u term. I don't have the paper in front of me but there's no way it isn't in there.

alphaRhoPhi is the convective mass flux for a multi-phase mixture. Phi is the convective flux for simple mixtures. Get used to seeing it.... It's everywhere.

Thank you.