Film Cooling Effectiveness Superposition Calculation of Double-Row Injection Holes on Turbine Vane

Film cooling effectiveness superposition of double-row injection holes on the turbine vane was studied by infrared temperature measurement experiment. The Sellers superposition method and a modified Sellers method were adopted for dustpan-shaped hole and cylindrical hole. Numerical simulations were implemented to analyze the film superposition mechanism. It is found that the Sellers method is more accurate on the suction side than the pressure side. Injection film of the two types of holes exhibits different superposition modes. Cylindrical hole are “blocky-like” superposition. Dustpan-shaped hole are “sheet-like” superposition. The counter-rotating vortex pairs and separation of the film are the main factors affecting the accuracy of Sellers film superposition method. The modified method can significantly improve the superposition prediction accuracy for almost all situations. The modified method reduces superposition errors from 28% to 3% for the cylindrical hole, and from 42% to 13% for the dustpan-shaped hole on the suction side. It reduces superposition errors from 30% to 8% for the cylindrical hole, and from 23% to 15% for the dustpan-shaped hole on the pressure side.