LEADING EDGE FILM-COOLING EFFECTS ON TURBINE BLADE HEAT TRANSFER

Abstract

A three-dimensional Navier-Stokes code has been used to study the effect ofspanwise pitch of shower-head holes and coolant to mainstream mass flow ratio on the adiabatic effectiveness and heat transfer coefficient on a film-cooled turbine vane. The mainstream is akin to that under real engine conditions with stagnation temperature 1900 K and stagnation pressure 3 MPa. It is found that with the ratio of coolant to mainstream mass flow being fixed, reducing the spanwise pitch for shower-head holes (P) from 7.5d to 3.0d, where d is the hole diameter, increases the average effectiveness considerably over the blade surface. However, when P / d = 7.5, increasing the coolant mass flow increases the effectiveness on the pressure surface but reduces it on the suction surface owing to coolant jet lift-off. For P / d = 4.5 or 3.0, such an anomaly does not occur within the range of coolant-to-mainstream-mass-flow ratios analyzed. In all cases, adiabatic effectiveness and heat transfer coefficient are highly three-dimensional,

Address correspondence to Dr. Vijay K. Garg, AYT Corporation, c/o NASA Lewis Research Center, MailStop 5-11, Cleveland, OH 44135-3191, USA.

Notes

Address correspondence to Dr. Vijay K. Garg, AYT Corporation, c/o NASA Lewis Research Center, MailStop 5-11, Cleveland, OH 44135-3191, USA.