热辐射对气膜冷却叶片冷却性能影响

针对一种带有气膜冷却结构的涡轮一级导向叶片进行气-固-热耦合数值模拟，通过比较考虑/不考虑热辐射的温比和综合冷却效率，分析了多种辐射因素对叶片表面温度和冷却性能的影响。结果表明:入口黑体辐射温度在1200~1900K之间，叶片表面发射率在0.3~0.7之间时，考虑热辐射作用均会使叶片表面温度明显上升。入口黑体辐射温度1600K，叶片表面发射率为0.5时，叶片压力面温度整体上升约100K，叶片表面最高温度点（1350K）温度上升约50K；气体辐射对叶片吸力面和尾缘区域造成5%左右的温升；考虑辐射作用使得叶片综合冷却效率下降，叶片前缘和压力面尽管布置密集的气膜孔仍然难以满足冷却需求，综合冷却效率下降至0.3以下。 

Effect of thermal radiation on the heat transfer performance of a film cooling vane

For a film-cooled first stage turbine vane, gas-solid-thermal coupled simulation was used to analyze the effect of radiation factors on the temperature distribution and cooling efficiency by comparing the temperature ratio and cooling efficiency with consideration/without consideration of the radiation heat flux over the vane. It showed that when the inlet blackbody temperature changed from 1200K to 1900K and the emissivity of vane surface changed from 0.3 to 0.7, the vane surface temperature increased obviously while considering the effect of radiation factors. When the inlet blackbody temperature was 1600K and the surface emissivity of the blade was 0.5, the temperature rise of the pressure surface was about 100K, and the maximum temperature（1350K） of the blade surface increased about 50K. The gas radiation caused about 5% temperature rise on the surface of suction side and trailing edge. The cooling efficiency decreased while considering the thermal radiation, the vane leading edge and pressure surface were not able to meet the cooling requirements even though the gas film holes were close together, the overall cooling efficiency reduced to 0.3 or less.