Abstract
Experimental investigation on a turbulent channel flow over a traveling wave-like streamwise wall deformation is conducted. The wave propagates on a thin elastic rubber sheet. Parameters of the wave are comparable to the ranges for relaminarization performed by recent similar numerical studies for wall deformation or blowing and suction. The drag reduction rate is 40% at a bulk Reynolds number of 3300 and a skin friction approaches to the value of the uncontrolled turbulent flow as increasing the bulk Reynolds number. A two-dimensional PIV measurement clarifies a characteristic flow produced by the wave. A three-component decomposition for the velocities also shows the suppression of the near-wall turbulence.
