Influence of mainstream flow history on film cooling and heat transfer from two rows of simple and compound angle holes in combination

This paper describes the results of an experimental investigation into the effect of the mainstream flow history on the film cooling effectiveness and the heat transfer characteristics from the combination of one row of simpl e angle holes and one row of compound angle holes, The mainstream how histo ry includes: favorable pressure gradient factors in the range -1.11 x 10(-6 ) to +1.11 x 10(-6) and turbulence intensity in the range 0.3-4.7%. The pre sence of favorable pressure gradients in the how reduces the film cooling p rotection of the surfaces from both compound angle holes or combination of simple and compound angle holes, while the presence of adverse pressure gra dients increases the film cooling effectiveness at low blowing rate and dec reases it at high blowing rate. Increasing the turbulence intensity reduces the film cooling effectiveness from compound angle holes or combination of simple and compound angle holes, (C) 1999 Elsevier Science Inc. All rights reserved.