Time-varying turbulent flows over bluff bodies predicted by finite volume integration of Reynolds equations

Abstract

Dynamic flows over bluff bodies are simulated with standard models based upon Reynolds equations (k,ϵ)- turbulence closure and equilibrium boundary conditions. The equations are integrated by finite volume techniques. The model is applied to time varying, transverse flow over a cylinder at a plane boundary and the flow around a truncated cylinder in longitudinal oscillations. Well-behaved, plausible predictions are obtained. Accelerating flow tends to be attached even around sharp corners. Decellerated flow is associated with detachment. Laboratory scale force data are predicted reasonably realistically, without model adjustments. However, the lift force associated with a return wall jet over the transverse cylinder and the tiny damping force on the truncated cylinder are inaccurately predicted. Numerical diffusion is probably a main cause for these inaccuracies.