Resumen de The effect of jet angle and velocity ratio on turbine blade film cooling
This work is concerned with the thermal effect of the turbine blade by film cooling. The jet flow penetration and flow structure was simulated and solved numerically. This investigation presents a tool to obtain qualitative information about the penetration area and flow structure of the mixing flow at different jet angle configurations. Two models of airfoil (NACA 0021) with hole diameters d=0.1 and 0.2 cm were studied. The simulation was carried out using the commercial code (FLUENT 6.3). Several cases were considered; including three-velocity ratio, VR=0.3, 0.7, 1, 1.5, 2 and two jet suction angles, B of 37.5º and 90º, and four different angles of attack, a=0º, 5º, 10º, and 15º. The cooling films build up on the blade surface was simulated. The work gives a clear picture of the penetration area for the normal and angled-injection cases. The results at different sections, x/s=0.5 and 0.9 for the first and second model provided the optimum holes rows spacing and the low suction angle for maximum film cooling effectiveness.
