Investigation On The Characteristics Of The Flow And Heat Transfer Of Turbine Blade

As the aircraft’s heart, aero-engine plays a decisive role in improving the performance of the aircraft. And the improvement of aero-engine in performance depends largely on the rise of the total temperature before turbine. In recent years, the outlet temperature of the combustion chamber increases year by year, making the turbine blade working environment become more and more severe, what’s more, resulting in the blade working temperature also much higher than the temperature which is allowed by the metal. Therefore, we must take the way of effective cooling to protect the turbine blade, so as to ensure the reliability of the engine working and to extend the life of the aero-engine.The first stage vane of the turbine directly faces the thermal shock from gases exiting the combustion chamber, and the flow and heat transfer of the leading edge and margin plate region are very complex, so these regions more easily get erosion by high temperature gases. Therefore, this paper studies the characteristics of the flow and heat transfer on the leading edge and margin plate region respectively. The main contents are :For the flow and heat transfer of the turbine blade leading edge, this paper establishes 12 different blade leading edge structure models. By using the method of numerical calculation, to study the effect of Reynolds number of the secondary flow, blowing ratio, and the shape of film hole on the discharge coefficient and the surface average adiabatic cooling effectiveness. The research results show that,(1) In the same shape of film hole, the discharge coefficient of film hole increases with the increase of Reynolds number of the secondary flow, and at low Reynolds number of the secondary flow, the discharge coefficient increases obviously.(2) Under the same Reynolds number of the secondary flow, the discharge coefficient of compound film hole is higher than cylindrical hole.(3) With regard to the models which have holes in the suction surface of the blade, the average adiabatic cooling effectiveness increases with the increase of the blowing ratio first and then decreased, while it increases with the blowing ratio in the reattachment region of the cooling film. However, for the models which have holes in the pressure surface of the blade, the average adiabatic cooling effectiveness decreases with the increase of the blowing ratio near the exit of the film hole, and it decreases gradually along the blade surface.For the flow and heat transfer of the turbine blade margin plate region, this paper establishes several different margin plate gap models to investigate the temperature distribution under different margin plate gaps by using Fluent software. Research shows that, with the margin plate gap become larger, high margin plate value gradual advances and high temperature region gradually expands.