为进一步了解涡轮叶片上多排气膜间的流动及换热规律,选取对气膜冷却效率有影响的3种典型因素(叶片型面、吹风比、孔排方式)进行了实验及数值计算研究,验证了涡轮叶片气膜冷却效率叠加计算的适用性.结果表明:由于叶片型面曲率的存在,叶片吸力面为凸面气膜更容易吹脱,气膜孔后冷却效率叠加计算误差约为5％;叶片压力面为凹面气膜被压向壁面,前后排气膜间影响较大,叠加计算值比实验值约高13％.孔排排布方式对叠加计算结果同样有影响,叉排结构中气膜间呈现“块状叠加”现象,叠加计算值与实验值相比误差在5％以内.顺排结构中气膜呈现“层状叠加”现象,计算结果偏高,误差在10％左右.吹风比对冷却效率叠加计算准确性有较大影响,低吹风比时叠加计算较准确,随着吹风比增加叠加误差逐渐增大.针对叠加计算误差较大的工况,本文提出了相应的计算修正公式.%Experimental and numerical simulations were conducted on turbine blade to figure out influences of three typical factors (vane curvature,blowing ratio and hole arrangement) on superposition prediction of film cooling efficiency.Results show that because of the convex blade surface on the suction side,jet is easy to be blown off and the computational error of superposition of film cooling efficiency is about 5％.On the pressure side,jet is easy to be pressed onto the wall and the prediction becomes inaccurate,hence the superposition calculatio nresult is about 13％ higher than experimental value.Another significant influence results from hole arrangement,the superposition prediction on staggered hole arrangement is nearly the same as the measured value,while it is much higher for in-line arrangement.Blowing ratio also has an obvious influence on the accuracy of superposition prediction for film cooling holes on both pressure side and suction side.At low blowing ratio,results obtained by Sellers method agree well with the experimental ones,while as blowing ratio increases,the accuracy of superposition prediction is decreased.At last,modification of Sellers method is suggested to improve the prediction accuracy.
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