Research On Heat Transfer Characteristics Of High Pressure Turbine Blade

Film cooling is a common thermal protection method of aero engines,and it is also an important factor affecting engine performance.In order to verify the effectiveness of the film cooling structure,it is necessary to measure the blade heat transfer coefficient and film cooling effectiveness through experiments.This paper designed and built an experiment section for turbine blade heat transfer characteristics based on the cascade wind tunnel experiment platform,used infrared thermal imager and thermocouple to measure the temperature of blade surface.The transient response method was used to calculate the heat flow on blade surface.Finally,the heat transfer coefficient and film cooling efficiency of the blade at typical conditions were obtained,and the effective of mainstream Reynolds number and blowing ratio on heat transfer coefficient and film cooling effectiveness were analyzed.The experimental results showed that the heat transfer coefficient raised with the increase of mainstream Reynolds number,and the larger the Reynolds number was,the greater the increase of heat transfer coefficient was.At lowing ratio 1,the spanwise average adiabatic film cooling effectiveness on one suction side was 14-112%and 22-80%higher than that of the blowing ratio of 1.5 and 2.When the blowing ratio was 2,it could be observed that the film of suction side detached.At blowing ratio 2,the spanwise average adiabatic film cooling effectiveness on pressure side was slightly higher than that at blowing ratio 1 and 1.5.Numerical simulation was used to simulate the experimental conditions,and the reasons for the change of heat transfer coefficient and adiabatic film cooling effectiveness distribution were analyzed.The simulation results showed that with the raised of blowing ratio,the momentum of cold air jet from film cooling hole on suction side increased in the perpendicular direction to blade wall.When the blowing ratio reached 1.5,the cold air jet separates from the blade wall,resulting in the decrease of adiabatic film effectiveness near the film cooling hole outlet.Downstream far away from the outlet of the film cooling hole,the cold air reattached to the blade wall,which improved the adiabatic film effectiveness.The adiabatic film cooling effectiveness near the outlet of film cooling hole was high and the film separation was difficult to observe.