Large-Scale Control of Wall Turbulence

In the presence of a solid wall, the flow and thus the turbulence is directly influenced. Reduction of wall turbulence is of great significance for energy saving and environmental protection. Numerous drag control strategies have been proposed and explored during recent decades, the vast majority of which concentrate on near-wall coherent structures, which can result in significant drag reductions at low Reynolds numbers. However, whether these drag control methods can continue to be effective at high Reynolds numbers remains unresolved. This question is crucial because the flow physics involved in drag reduction changes at high Reynolds numbers (because the contribution of large-scale structures to the skin friction grows with the Reynolds number). Large-Scale Control of Wall Turbulence synthesizes and interprets research on large scale drag control. In particular it looks at the underlying physical mechanisms of the large-scale control, especially investigation of the coherent structures, and the statistical approach through the momentum flux as well as the energy flux.