Intermittent structure of a transpired turbulent boundary layer

Turbulent structure of the intermittent region of a transpired boundary layer has been investigated for different injection rates using a conditional sampling method. The intermittency function is generated from the time-derivatives of the instantaneous Reynolds shear stress, and the threshold levels determined for the nontranspired case are applied to the transpired one. The results of the conditional averages have shown that the transpiration affects the mean and turbulent quantities in the outer intermittent region as well as those near the wall, and that the fluid motion in the turbulent bulge exhibits, on average, a large-scale clockwise rotation with its mean vorticity being increased by the transpiration.