Evaluation of the unsteady RANS capabilities for separated flows control

E. Garnier (1) , P.Y. Pamart (2) , J. Dandois (3) , P. Sagaut (4)

1 LIENSs - LIttoral ENvironnement et Sociétés
2 SNECMA Villaroche [Moissy-Cramayel]
3 ONERA - The French Aerospace Lab [Meudon]
4 DALEMBERT - Institut Jean Le Rond d'Alembert

Nowadays, unsteady RANS methods are the only techniques usable in the industry to design a control device based on a periodic excitation of the flow. This paper aims at evaluating the potential of such methods by comparing their performances with respect to LES computations taken as a reference. The chosen test case is a rounded backward facing step proposed by Dandois et al. [1]. The frequency response of this flow to the periodic excitation of a synthetic jet is computed both with LES and with four different URANS models. It is demonstrated that the optimal frequency identified by best URANS models is close to the one of LES. Nevertheless, the amplitude of separated bubble surface reduction is underestimated by URANS models.

Mots clés: Flow control; Synthetic jet; LES; URANS

Domaines: Mécanique des fluides [physics.class-ph]

E. Garnier, P.Y. Pamart, J. Dandois, P. Sagaut. Evaluation of the unsteady RANS capabilities for separated flows control. Computers and Fluids, 2012, 61, pp.39-45. ⟨10.1016/j.compfluid.2011.08.016⟩. ⟨hal-01298918⟩