International Journal of Heat and Mass Transfer, Vol.39, No.11, 2283-2292, 1996
Bulk Flow Pulsations and Film-Cooling .2. Flow Structure and Film Effectiveness
Experimental results are presented which describe the effects of bulk flow pulsations on film cooling from a single row of simple angle film cooling holes. The pulsations are in the form of sinusoidal variations of static pressure and streamwise velocity. Distributions of time-averaged Reynolds shear stress are presented for quasi-steady film conditions at x/d of 4.5, 9.8, 16.4 and 24.1, where x is streamwise distance from the downstream edge of the holes and d is hole diameter. Distributions of streamwise mean velocity are also presented for the same locations. Important changes from the imposed bulk flow pulsations are evident in all measured quantities, especially just downstream of the holes at x/d = 4.5. Important changes to local and spanwise-averaged film effectiveness also occur as the coolant Strouhal number becomes greater than 1-2 and the film moves from quasi-steady to non-quasi-steady behavior.