ADIABATIC EFFECTIVENESS AND HEAT-TRANSFER COEFFICIENT ON A FILM-COOLED ROTATING BLADE

A three dimensional Navier-Stokes code has been used to compute the ad iabatic effectiveness and heat transfer coefficient on a rotatingfilm- cooled turbine blade. The blade chosen is the United Technologies Rese arch Center (UTRC) rotor with five film-cooling rows containing 83 hol es, including three rows on the shower head with 49 holes, covering ab out 86% of the blade span. The mainstream is akin to that under real e ngine conditions with stagnation temperature 1900 K and stagnation pre ssure 3 MPa. The blade speed is taken to be 5200 rpm. The adiabatic ef fectiveness is higher for a rotating blade as compared to that for a s tationary blade. Also, the direction of coolant injection from the sho wer-head holes considerably affects the effectiveness and heat transfe r coefficient values on both the pressure and suction surfaces. In all cases the heat transfer coefficient and adiabatic effectiveness me hi ghly three-dimensional in the vicinity of holes but tend to become two -dimensional far downstream.