Effects of Near-Wall Control on the Structure and Dynamics of Wall- Bounded Turbulent Flows

摘要

Improved understanding of unsteady flow physics has led to a wealth of flow control applications in which fluid perturbations are deliberately introduced into a large-scale flow with the goal of affecting its global characteristics. Research into these methods has included separation control, enhanced mixing, and reduction of turbulent skin friction. Interest in turbulence control has grown due to numerical computations at low Reynolds number flow 3, 4, 5, which indicate that the turbulence and drag can be reduced by a variety of fluidic actuations. The difficulty with these methods is that even though computationally they provide promising results, implementing them in a physical experiment proves very difficult. Other actuation methods that have been studied experimentally include localized heating, piezo-electric flaps, oscillatory blowing, synthetic jets, surface motion, and plasma discharge.