Simulation of unsteady turbulent flows with the effect of fluctuating external velocity by using quasi-steady models

摘要

Simulation of unsteady turbulent boundary layer flow with the effect of fluctuating external velocity by quasi-steady models is analysed. The problem of oscillating turbulent flows with fluctuating external velocity and radial frequency is very often encountered in practice in a variety of applications. Three-D representation shows that Vpar decreases and Vper increases. In the case of η, velocity fair saturated after some specified value. “In-plane” and “out-of-plane” velocity components show that parts of velocity fluctuate in-phase and at a phase of 90° with respect to the outer-flow velocity. Amplitude of velocity oscillation increases and becomes constant at certain values of ω. By the influence of EV, eddy viscosity reaches a maximum and then becomes constant.