Experimental Investigation And Fluid-solid Coupling Numerical Calculation Of Heat Transfer Characteristics In Turbine Casing

Turbine casing is the key support of aircraft engine turbine section and the major component to control engine turbine blade tip clearance. It bears the main thermal load, mechanical load and aerodynamic load so that the working environment is very bad. Hot-end components cooling method research has long been the hot spot and difficulty of high temperature gas engines at the present stage. As a typical hot-end component of gas turbine, turbine casing channel structure is usually very irregular due to the layout need. The structure is complicated and usually contains different flow forms which make it differ in heat transfer performance and hard to find uniform computing method. At present, the experimental method and three-dimensional steady state heat transfer numerical method are taken as the most effective ways to study the flow and heat transfer issues.This paper takes a porous array doubling-plate turbine casing structure as study object. A fundamental experimental study was conducted to research the flow and heat transfer characteristic in the casing and the experimental data was compared with the fluid-solid coupling heat transfer calculation results from commercial software ANSYS Fluent. The two methods were in good agreement about flow field and temperature data, the coupling calculation could be considered of certain accuracy and credibility within a certain error range.The turbine casing cooling is actually a combined cooling containing impingement cooling and film cooling. Experiment with fixed heat source instead of the actual hot gas has brought a certain amount of defection. This paper used fluid-solid coupling heat transfer method to study the turbine casing with a combined "impingement cooling + film cooling" structure under its real working condition about the heat transfer characteristics. First, for the initial model, the influence rules of cooling efficiency, temperature distribution and heat flux under aerodynamic parameter of different blow ratio were studied and the film streamwise and spanwise effectiveness were analyzed. Then the influence rules under geometrical parameter of different jet distance H/L and different film hole angle β of the combined cooling about heat transfer characteristics were studied. The results showed that reduce both the jet distance and film hole angle could promote the average cooling efficiency on the impingement plane and the film plane and reduce the film hole angle could also effectively promote film streamwise and spanwise effectiveness.The related research in this paper can provide valuable reference for engineering design.