Numerical investigation on conjugate heat transfer of impingement/effusion double-wall cooling with different crossflow schemes

摘要

A numerical study is conducted on the conjugate heat transfer of the impingement/effusion double-wall cooling with different crossflow schemes. A small jet-to-plate spacing of 1.5 times jet diameter is used. Three crossflow schemes (zero, maximum, blocked maximum) are considered for the impingement/effusion cooling, and the impingement cooling with maximum crossflow is numerically simulated for the performance comparisons. The SST k-omega turbulence model and the polyhedral mesh are used in the computations. Over the Reynolds numbers from 10,000 to 30,000, the impingement/effusion cooling shows higher overall cooling effectiveness by up to 28.0% than the pure impingement cooling due to the external cooling film and the enhanced internal heat transfer. For the impingement/effusion cooling, the cooling performance is related to the crossflow scheme, and the blocked maximum crossflow scheme shows more advantages. Compared to the impingement/effusion cooling with maximum crossflow, the blocked maximum crossflow case prevents the hot gas from invading into the internal cooling channel and shows better cooling performance for the Reynolds number of 10,000; compared to the zero crossflow case, it shows similar overall cooling performance with less discharged flow. Moreover, the detailed flow structure in the impingement/effusion cooling system is obtained to reveal the heat transfer mechanism.