부산대학교 도서관

A double-wall cooling configuration including impingement holes and film holes with conformal pins is studied by CFD numerical simulation in this paper. The influences of three different injection directions of film holes at six blowing ratios ranging from 0.4 to 2.5 on conjugate heat transfer characteristic are investigated. Impingement-only arrangements with corresponding pin directions are adopted to illustrate the film cooling gains and the impingement cooling contribution. The results indicate that the effect of different pin directions on overall cooling effectiveness is non-significant. At low blowing ratio, the forward injection arrangement has higher overall cooling effectiveness since greater gain of film cooling, and is transcended by reverse injection arrangement as coolant supplement increases. Moreover, although the cooling effectiveness for normal injection case is the lowest within the whole range of mass flow rate, it possesses the most uniform distribution of cooling effectiveness in downstream region at high blowing ratio.