Numerical Simulation Of Film Cooling On Gas Turbine Blade

Improve the inlet temperature of the gas turbine is the key to improve theefficiency and the rise of the inlet temperature largely depends on the heat-resistingmaterial of gas turbine blade. Now, heat-resisting material cannot meet therequirements of high temperature gas, so turbine blade cooling technology hasbecome the key of the gas turbine. Blade adopts a lot of cooling ways and the filmcooling is very important for all of them. This article used the method of numericalsimulation to analysis the film cooling. Through the research of film cooling in singlespan slab model to analysis the film cooling in leading edge of gas turbine blade. Inthis paper, the effects of various parameters on the film cooling were compared.Through numerical simulation of film cooling in single span flat, we canintuitively understand the flow in the hole and surface. Compared the differentcovering conditionings of cold air on the surface of the flat in different blowing ratio(cooling jet from the mainstream of the ratio of the mass flow rate). Results show thatthe high blow ratio leads to the cold air away from the surface and makes poorcooling effect. And when the other conditions are same, although reduce the aperturecan save rate of flow, the cooling effect is not ideal.To the blade leading edge film cooling, the influence of different blowing ratio,density ratio, free stream turbulence,the jet Angle and the cooling structure wasstudied. Too low blow ratio will lead to the mainstream flows into the jet hole of thehead, and high blow ratio will lead the jet out of blade. High-density jet is more easilykept at the surface than low density jet. Therefore, the film cooling at high density ismore effective than in low density and the cooling efficiency increases with thedensity increasing. The cooling efficiency at high turbulence is low than at lowturbulence, the influence of turbulence to low blow ratio is bigger than to the highblow ratio and to pressure surface is bigger than to the suction surface. Change the jetAngle can improve the cooling effect of much of the head, But makes the coolingeffect of the bottom area become very poor. Increase the film holes in the suction andpressure side can improve the cooling efficiency where the downstream of frontal areacovering less, so as to improve the cooling efficiency of the blade.