Passive scalar statistics in a turbulent channel with local time-periodic blowing/suction at walls

Direct Numerical Simulations (DNS) of an incompressible turbulent channel flow with local forcing at the walls are performed. Time-periodic blowing/suction is applied by means of narrow spanwise slots located at the lower and upper walls in x/Lx=0 (where Lx is the channel length). The normal perturbing velocity is varied sinusoidailly in time at several perturbing frequencies between 0.16