About RANS (and hybrid RANS-LES) k — νt turbulence models : recent advance based on databases and an analytic theory
Orateur : Pr. Emmanuel Plaut / Université de Lorraine - Mines Nancy / Lemta
Abstract : The classical RANS turbulence models for CFD are, for the ones most used in engineering studies, eddy-
viscosity models like the k − e or k − ω models. However, these models have flaws, not only regarding the
eddy-viscosity assumption. Based on the channel flow DNS database of Lee & Moser 2015, I will confirm for
both models the relevance of the k equation but also the flaws of the highly heuristical e or ω equations, and
display "wall damping problems".
I will also advocate the νt model of Spalart & Allmaras, and the k − νt
models of Menter et al. Interestingly, these latter models, also named ‘Scale - Adaptive’ (SA), are claimed to
be "instability sensitive", in that they may run in hybrid RANS-LES mode.
I will then present briefly the high Reynolds number analytic theory of Stefan Heinz 2019 for some mean
fields of "turbulent wall flows" : zero - pressure gradient boundary layer, channel and pipe flows.
Séminaire en mode mixte à 10h00 :
en présentiel : salle 233-235 Labus de l’Ecole Centrale
en visioconférence Teams