Numerical analysis of film cooling from micro-hole

The performance of the coolant for film cooling from micro-hole was numerically computed over a flat plate and compared with the performance of the coolant from macro-hole. The comparison between the prediction from two equation standard and realizable k-ε turbulence models with two-layer near wall treatment was used to validate the suitability of the turbulence model in predicting the performance. The results showed that the realizable k-ε turbulence model predicted the performance closer to the experimental results at high blowing ratio (M = 1). However, at low blowing ratio (M = 0.5) there was not much variation in prediction between the turbulence models. The centerline effectiveness of the coolant from micro-hole was found to be higher in the vicinity region than from the macro-hole. It was also predicted that the coolant from micro-hole spreads broadly in the lateral direction than the coolant from macro-hole. The use of multiple (two stream-wise located) micro-holes was found to increase the lateral spreading of coolant.