Effect of Impingement/Effusion Hole-Area Ratio on Discharge Coefficients of Double Cooling Wall

Abstract

This paper presents the experimental investigations on the discharge coefficients of impingement/effusion double flat wall with the impingement/effusion hole-area ratios of 1, 0.64 and 0.28. The impingement and effusion walls researched have equal numbers of holes per unit surface area in diamond arrays. The impingement holes are normal to the wall surface, the effusion holes are 30 degree to the wall surface in the sreamwise direction of the main flow, and both the impingement and effusion holes are arranged in the staggered mode. The CFD code was also applied to investigate the flow field within the impingement/effusion wall in detail. The experimental results indicated the relationship of the discharge coefficients of the single impingement wall, effusion wall and double wall with the overall pressure parameter of double wall in different impingement/effusion hole-area ratios, and were explained in the CFD results.