Effects of pressure gradient on film cooling effectiveness from two rows of simple and compound angle holes in combination

This paper describes the results of an experimental investigation into the effect of pressure gradient on the film cooling effectiveness from compound angle holes at both injection rows or the combination of one row of simple angle holes and one row of compound angle holes. Two pressure gradients were used in the range from -1.11 x 10(-6) to +1.11 x 10(-6). The presence of a favorable pressure gradient tends to increase the dilution of the injected coolant jets, which results in a reduction of the film cooling protection over the surface. The presence of an adverse pressure gradient at high blowing rate tends to dilute the film coolant even at a higher rate than that when zero or favorable pressure gradients are present. (C) 2003 Elsevier Ltd. All rights reserved.