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

Abstract

Abstract 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 simple angle holes and one row of compound angle holes. The mainstream flow history includes: favorable pressure gradient factors in the range −1.11 × 10 −6 to +1.11 × 10 −6 and turbulence intensity in the range 0.3–4.7%. The presence of favorable pressure gradients in the flow reduces the film cooling protection of the surfaces from both compound angle holes or combination of simple and compound angle holes, while the presence of adverse pressure gradients increases the film cooling effectiveness at low blowing rate and decreases 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.