Some commonly used turbulence models include k-epsilon, k-omega and shear stress transport (SST) models. The k-epsilon model is a best candidate for flow away from the wall (e.g. free surface flow region), while the k-omega model is best suited for near the wall flow region (e.g. adverse pressure gradient flow region). The choice of most appropriate turbulence model for any turbulent flow problem may be extremely difficult for young computational fluid dynamists, hence the need for this germane question.
The most suitable turbulence model depends on the level of accuracy and the flow region or quantity of interest for the computation. If mesh size is a constraint, the k-epsilon model with wall functions/the realizable k-epsilon model might be the way to go. This is because you can get away with much higher y-plus values. The k-omega and the k-omega SST models require near wall grid resolutions resulting in y-plus under 1 but the k-omega SST model may be the way to go if grid sizing is not a constraint. For rocket nozzles, if resolving the near wall behavior is necessary, then this should be the choice. If much greater accuracy is desired, one may even look into hybrid RANS/LES and even LES.
@ Siddhant Desai Thanks for your time and insightful response. It is well appreciated.
The SST k-ω model is a hybrid of the best of k-ω and k-ε. This model uses the k-ω model near walls, and transitions to k-ε model in the open flow field. It’s popular in aerospace and turbo-machinery applications.
So SST is the most effective model for young computational fluid dynamists.
@Andrii Rogovyi Thanks for your insightful comment. It is noted and well appreciated.
Based on own experience I would also recommend using curvature correction option as well as Kato-Launder turbulence production limiter coupled with the SST model. This is strongly recommended when complex turbulent flows are under investigation.
@ Oleg Evdokimov Thanks for your invaluable contribution. It is well appreciated.
Academic resources on turbulent flows are provided on the project references:
SINGLE PHASE AND MULTIPHASE TURBULENT FLOWS (SMTF) IN NATURE AND ENGINEERING APPLICATIONS | Jamel Chahed | 3 publications | Research Project (researchgate.net)
Jamel Chahed Thanks for the academic resource materials. It is well appreciated.
SST k-ω model is a possible response to your simulation needs. Also you need to check the documentation related to your simulation needs
First-order turbulence models determine two turbulence scales; they are therefore more or less equivalent. I will choose for my part k-epsilon model being the simplest and the best parameterized. I will rather focus on the conditions of implementation and on the boundary conditions. To simulate flow from a nozzle, I would start the mesh inside upstream of the outlet with appropriate boundaries conditions
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