关键词: 流热耦合；辐射换热；隔热屏；气膜冷却；离散坐标法

Abstract: In order to investigate the effects of heat conduction，convection and radiation heat transfer on film cooling performance of flat plate under three different total temperature ratio([Rt])of the primary fluid to the secondary fluid conditions，discrete ordinates radiation model and three-dimensional numerical simulation of fluid-heat coupling were conducted under two conditions of coupling calculation(without considering the effect of radiation heat transfer)and radiation heat transfer calculation(considering the effect of radiation heat transfer)，and contrastive studies were carried out with the results of the adiabatic condition. Change laws of film cooling effect，flow field，coolant heat load per unit area and discharge coefficient have been obtained. The results show that the film cooling effect decreases in the streamwise direction and decreases with the increase of Rt. The value of film cooling effect in the film covered area is larger than the value of both sides at the same spanwise location. The maximum value(94.5%)of film cooling effect gradient in the spanwise direction happens under the adiabatic condition and the result of radiation heat transfer and conjugate calculation is 13.5% and 9.8% respectively. Compared with the results of conjugate condition，the influence of radiation heat transfer on the film cooling effect become larger in the streamwise direction，the spanwise temperature gradient increases near the film cooling hole and the coolant heat load increases by 92.8%，but the difference of discharge coefficient is slightly，of 1.1%，between the two cases. The discharge coefficient considering the effect of radiation heat transfer is lower 13.1% than the value of adiabatic condition and has a small decline，of 1.1%，with the increase of total temperature ratio.

Key words: Conjugate heat transfer; Radiation heat transfer; Heat shield; Film cooling; Discrete ordinates method