Numerical Study of the Blowing Angle Effecton Effusi on Cooling Effectiveness

The influences of the coolant flow blowing angle α on the effusion cooling effectiveness of a porous plate were investigated.Nine cases were studied,which cover three blowing angles of α=30°,60°,90° and for each angle three blowing ratios of M=0.5,1.0,2.0.The results show that with the increase of α the cooling effectiveness reduces for all the calculated cases.For cases of α=30° and 60° the distribution of cooling effectiveness η along the whole plate are very similar for any given blowing ratio.While for the cases of α=90°,the distributions of cooling effectiveness are quite different.Although the cooling effectiveness of the cases with α=90° for any given blowing ratio is the worst among the three angles stated,its absolute value is still quite high compared with the conventional film cooling.