Experimental investigation of the effectiveness of jet impingement cooling system on the pressure side of the turbine blade

The effectiveness of the jet impingement system on the turbine blade pressure side has been experimentally investigated. The effects of height-to-diameter ratio and air velocity on the effectiveness of jet impingement were studied. Experiments was performed under varying height-to-diameter ratios (H/D = 5, 10, 15, 20) where the distance from the nozzle to the pressure side surface ranged from 20, 40, 60 and 80 mm with a constant nozzle diameter of 4 mm. The Nusselt number is calculated to determine the cooling effect of the pressure side model surface. Experiments were also performed at varying air velocity at 6.4 m/s and 12.6 m/s. The findings revealed that there was no direct relationship between Nusselt number and H/D ratio where the optimum cooling impact at a velocity of 6.4 m/s was found to be at H/D=15, whereas at a velocity of 12.6 m/s it was found to be at H/D=5. The findings also reveal that the amount of Nusselts rises as the air velocity increases