Drag reduction in a turbulent boundary layer using periodic blowing through one array of streamwise slits etc15 Tracking Number 255Presentation: Session: Control 2 Room: Room D Session start: 15:00 Tue 25 Aug 2015 Yinzhe Li bluelee333633@hotmail.com Affifliation: Institute for Turbulence-Noise-Vibration Interaction and Control, Shenzhen Graduate School, Harbin Institute of Technology, Shenzhen, China Yu Zhou zhouyu@hitsz.edu.cn Affifliation: Institute for Turbulence-Noise-Vibration Interaction and Control, Shenzhen Graduate School, Harbin Institute of Technology, Shenzhen, China Topics: - Control of turbulent flows, - Wall bounded flows Abstract: Active drag reduction of a turbulent boundary layer has been experimentally investigated using periodic blowing through one array of streamwise slits. Local skin-friction drag exhibits a strong dependence on control parameters, including the blowing amplitude A+ and frequency f +. A maximum drag reduction of almost 70% has been achieved at x+=33 downstream of the actuators. The near-wall structure under control are measured using smoke-wire flow visualization, hot-wire and PIV techniques. All the results point to a pronounced change in the structure of the boundary layer and a significant increase of the mean energy dissipation rate. |