hi just wanna know if a dilatation dissipation term is included as a source#sink term in the epsilon or other equation, in any turbulence model?? this kind of terms allow to take into account interaction between turbulence and compressibility and especially model the reduced (and observed) spreading rate of a mixing layer for compressible flows

thanks

Hi Yann,

I have noticed this term is indeed missing, and this observation was confirmed by CHAM:

"I can confirm that the dilation term is omitted in the generation term that is used in both the turbulence modelling and the mechanical dissipation term of the static enthalpy equation. This means the generation term is formally valid only in flows with uniform density. The dilation term has never been present in any release of PHOENICS.

Best regards, Dr Michael Malin"

hi Michael,

thanks for your confirmation, but your also mean that the viscous dissipation is not included in the energy disspation or it is just the divergence term (of the dissipation term) which is not included... it is very stricking for this kind of code( at this price)that such terms are not included...cause modeling of some turbulence-compressibility interaction (shock damping in a jet, spreadind rate)will be quantitatively wrong..

thanks for your reply

yann bartosiewicz, Phd

Hi Yann,

There is a slight misunderstanding here. In may last posting I only CITED Dr. Malin's reply to me in response to a question similar to yours.

If you need further details, I suggest that you contact Dr. Malin at CHAM support directly.

Rami