Turbulence Model in axisymmetric nozzle simulation
 

Hi

I am simulating an axisymmetric nozzle. I have an issue with which turbulence model to use. Currently I am using standard K-epsilon and i am not getting any shock wave inside the nozzle. When I switch to SST K omega i get shock wave in the flow.

I would like to ask which is the recommended turbulence model for these type of flow

By intuition, std k-eps model is diffusive and hence may smear out the sharp gradients responsible for shocks. Have you tried realizable model? It is deemed to be good in modelling jets.

OJ

Yes, Just tried realizable.. it also shows a shock wave

Hi, could i ask you what do you mean by diffusive?

K-epsilon does not behave well in large pressure gradient, one like shocks, I'd suggest to stick with SST. By diffusive he means the behavior of the solver, like for eg:- Picks the information from the succeeding nodes and moves forward

I see that the SST k-omega model is more suitable for compressible flow into a nozzle for its good behaviour in adverse pressure gradients (shock) and separating flow. Thank you for your help!