Numerical and Experimental Investigations on Film Cooling Performance of Trench Model Embedded with Compound Angle Film Hole Jets

The Trench film cooling is a cooling technique where film cooling holes are embedded within a cut slot made on the surface with the application of thermal barrier coatings. The goal of the present investigation is to compare the cooling effectiveness of trench model embedded with compound angled film hole viz. 45°, 90°, 135° through numerical and experimental investigation at two different blowing ratios. The width and depth of trench are maintained at 2D and 0.7D, respectively, with D as the hole diameter. Results of the study show that trench model embedded with 90° compound angled film hole delivered highest cooling effectiveness for two tested ratios of blowing between coolant and mainstream flows. Experimental results on film cooling effectiveness produced good agreement with computational results.