气膜孔堵塞对叶片吸力面换热性能影响

Influence of Blockage Inside Film Cooling Hole on Heat Transfer Performance of Vane Suction Surface

为研究热障涂层喷涂过程造成的气膜孔堵塞对叶片吸力面换热特性的影响,利用数值模拟方法分析了叶片吸力面气膜孔堵塞比为0.2~0.8时传热系数的变化规律。将吹风比作为控制冷热流体流量比例的气动参数,在其变化范围为0.5~2.0情况下,详细分析了气膜孔堵塞对孔下游肾形涡、叶片壁面传热系数二维分布和展向平均传热系数的影响。结果表明:在吹风比相同的情况下,堵塞比越大,传热系数增幅越大;堵塞使肾形涡尺度和强度显著增大,导致壁面传热系数增大,吹风比越大,这种效应越明显;相比于无堵塞情况,堵塞比为0.2时传热系数基本不变,堵塞比为0.5时传热系数增大5%~7.2%,堵塞比为0.8时传热系数增大9%~12%。

In order to study the influence of the film cooling hole blockage caused by the thermal barrier coating process on the heat transfer performance of vane suction surface,the numerical simulation method was used to analyze the change rule of heat transfer coefficient when the film cooling hole blockage ratio of the vane suction surface was from 0.2 to 0.8.The blow ratio was used as the aerodynamic parameter for controlling the cold and hot fluid flow ratios,and the influences of film cooling hole blockage on the downstream kidney-shaped vortex,the 2D distribution of heat transfer coefficient of the vane wall surface and the spanwise average heat transfer coefficient were analyzed in detail when the blowing ratio was from 0.5 to 2.0.The results show that in the case of the same blow ratio,the larger the blockage ratio is,the greater the increase amplitude of the heat transfer coefficient is.The size and intensity of the kidney-shaped vortex increase significantly due to the film hole blockage,leading to the increase of heat transfer coefficient of wall surface.This effect becomes more obvious with the increase of the blowing ratio.Compared with the case without blockage,the heat transfer coefficient has little change at the blockage ratio of 0.2.The heat transfer coefficient is increased by 5%to 7.2%at the blockage ratio of 0.5 and is increased by 9%to 12%at the blockage ratio of 0.8.