冷却流量对涂层叶片冷却性能影响的数值研究

采用气热耦合数值方法研究冷却流量对热障涂层气冷涡轮叶片冷却性能的影响。分析表明：叶片的冷却效率随冷却流量的增加而增大,但增幅则逐渐下降。吸力面上,附加热障涂层的效果更好。基准工况下,温度的降幅为72.6K,冷却效率的增幅为6.5%。尾部部分区域内部冷却不足,热障涂层阻碍热量从金属表面向流体传递,金属表面温度升高,综合冷却性能下降,因此,只有配合高效的内冷技术,才能达到理想的冷却效果。

Numerical study on the effects of thermal barrier coating and cooling flow rate on cooling performance of cooled turbine blades

The effect of cooling flow rate on the cooling performance of a coated turbine vane with internal cooling is studied by using the conjugate heat transfer method. The analysis shows that: Cooling efficiency increases with the increase of cooling flow. However, the influence declines with the increasing of the cooling flow. Thermal barrier coating on the suction side is more effective than that of the pressure side. In the base case, the decrease in temperature is about 72.6 K which leads increase of cooling efficiency about 6.5 %. In the trailing edge, thermal barrier coating prevents the heat transfer from the metal surface to the mainstream on the regions with insufficient internal cooling which increase the metal surface temperature, and thus decline the overall cooling efficiency of the vane. Thus, sufficient internal cooling is the promise of improving the overall cooling performance for a coated turbine vane.