Turbulence and Shear Flow Phenomena -1 First International Symposium

ISBN Print: 1-56700-135-1

ACTIVE CONTROL OF FULLY DEVELOPED TURBULENT CHANNEL FLOWS

Abstract

Active feedback control strategies are performed with the aim of reducing skin-friction drag and the ultimate goal of inducing relaminarization by blowing and suction on the boundary walls of turbulent channel flows. Direct numerical simulation enabled us to detect the wall normal velocity at various distances from the wall and impose blowing and suction with various values of the amplitude and phase. Some strategies were successful to achieve up to 30% drag reduction with suitable combinations of sensing location, amplitude and phase. In this study, we also investigated the effect of control scheme on the passive scalar field, induced by a constant temperature difference between the walls.