LES approach coupled with stochastic forcing of subgrid acceleration in a high-Reynolds-number channel flow

Rémi Zamansky (1) , Ivana Vinkovic (1) , Mikhael Gorokhovski (1)

1 LMFA - Laboratoire de Mecanique des Fluides et d'Acoustique

In this paper, the high Reynolds number channel flow is simulated by numerical approach at coarse resolution, in which the instantaneous acceleration is decomposed into filtered and subgrid parts, and then both components are modeled. The filtered acceleration is modeled in the framework of the LES approach. The model for the subgrid acceleration is based on two stochastic processes. The first is for its norm, and is based on statistical universalities in fragmentation under scaling symmetry, providing correlation of subgrid forcing across the channel. The second is for its orientation, and is based on the Brownian motion on a unit sphere in order to represent a stochastic relaxation towards full isotropy away from the wall. Two main parameters of the stochastic process include the Reynolds number based on the friction velocity, and the channel half-width. In order to assess the capability of the model proposed, the paper illustrates its application versus recent high Reynolds number DNS, including DNS performed in this paper.

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

Rémi Zamansky, Ivana Vinkovic, Mikhael Gorokhovski. LES approach coupled with stochastic forcing of subgrid acceleration in a high-Reynolds-number channel flow. Journal of Turbulence, 2010, 11, pp.1-18. ⟨10.1080/14685248.2010.496787⟩. ⟨hal-00566071⟩