Geometric evolution of the Reynolds stress tensor

Sergey L. Gavrilyuk (1, 2) , Henri Gouin (1)

1 IUSTI - Institut universitaire des systèmes thermiques industriels
2 SMASH - Simulation, modeling and analysis of heterogeneous systems

The dynamics of the Reynolds stress tensor for turbulent flows is described with an evolution equation coupling both geometric effects and turbulent source terms. The effects of the mean flow geometry are shown up when the source terms are neglected: the Reynolds stress tensor is then expressed as the sum of three tensor products of vector fields which are governed by a distorted gyroscopic equation. Along the mean flow trajectories, the fluctuations of velocity are described by differential equations whose coefficients depend only on the mean flow deformation. If the mean flow vorticity is small enough, an approximate turbulence model is derived, and its application to shear shallow water flows is proposed. Moreover, the approximate turbulence model admits a variational formulation which is similar to the one of capillary fluids.

Mots clés: Reynolds stress tensor; Turbulent flows; Gyroscopic equation; Capillary fluids; Variational principle

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

Sergey L. Gavrilyuk, Henri Gouin. Geometric evolution of the Reynolds stress tensor. International Journal of Engineering Science, 2012, 59, pp.65-73. ⟨10.1016/j.ijengsci.2012.03.008⟩. ⟨hal-00371444v3⟩