Résumé
The proposed communication deals with hybrid RANS-LES modeling. The target application is the study of flows around rotating machines like helicopters and drones. In fine, the simulations should provide accurate estimates concerning the noise emission. Each of these flows can involve mean and high Reynolds turbulent regions with detached eddies and with thin laminar and turbulent boundary layers. A hybrid model, like DDES, is then mandatory, with possibly an improved resolution of LES regions, which are mainly turbulent wakes. It is then interesting to apply there a more sophisticated LES model than the LES part of DDES. In our study, we use there the Dynamic variational multiscale model (DVMS). In the other regions, a DDES or simply a RANS modeling is applied. In both cases a two-equation closure is chosen. After a discussion of the modeling ingredients, we shall present a comparison of the RANS, LES, and hybrid models for two series of flows. Although computed by many researchers, flows around cylinders remain difficult to predict. The comparison will continue with a flow around a cross shaped mixing device rotating inside a cylinde.