Sixth International Symposium on Turbulence and Shear Flow Phenomena
DOI: 10.1615/TSFP6
FRICTION DRAG REDUCTION THROUGH DAMPING OF THE NEAR-WALL SPANWISE VELOCITY FLUCTUATION
pages 749-754
DOI: 10.1615/TSFP6.1200
RESUMO
Direct numerical simulation (DNS) of a turbulent channel flow is performed in order to explore the possibility of reducing wall friction drag and saving energy through damping of the spanwise velocity fluctuation. Starting from an idealized feedback control, we extend the idea to a practically realizable control in which wall information is used as sensor input and actuators of finite size are employed. A novel control loop is proposed based on the upstream streamwise wall shear stress. This control scheme enables drag reduction of up to 20% while energy input for the control scheme remains two orders of magnitude smaller than the pumping power for the uncontrolled flow.