Experiments of Reynolds stress manipulation during burst by blow/suction disturbance

The time sequence signals of instantaneous longitudinal,normal and spanwise velocity components at different vertical locations on the turbulent boundary layer over a flat plate were finely measured by constant temperature anemometry and double-sensor hot-wire probe in a wind tunnel.By the criteria of the module-maximum of locally averaged longitudinal velocity structure function,the conditional phase-averaged waveforms of different velocity components and Reynolds stress were detected during the burst.After disturbance,it is found that the friction coefficients and the Reynolds stress are reduced;the phase-differences between the phase-averaged waveforms of longitudinal vertical velocity and the spanwise velocity components are changed.When their phase differences are about odd times of π/2,the Reynolds stress is depressed to about zero.The mechanisms of production,diffusion and transportation of Reynolds stress are changed in wall-bounded turbulent flow and the Reynolds stresses are restrained to a certain degree.