涡轮叶片双排气膜冷却效率叠加计算准确性研究

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 calculation result 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.