Investigation On Heat Transfer Characteristics And Cascade Arerodynamic Performance Of Squealer Tip With Fins

In order to increase the thrust of the aero engine, turbine inlet temperature raised continuously, resulting in the enhanced heat load of the turbine. The effectively cooling method must be used to guarantee its appropriate operating temperature. The heat transfer on turbine blade tip is very strong because of the leakage flow and the corresponding heat transfer research is a hot issue on the design of the blade cooling structure. Heat transfer and the flow field in the blade tip gap were studied in detail by commercial software. The novel tip structure with fins, which can improve the spreading of coolant in film cooling by the surrounding flowing in the region of fins, were used to raise the usage of the coolant, resulting in the approach of synchronous control of the temperature and the flow.The concrete contents are as follows:(1) studying the impact of the attack angle on the heat transfer characteristics on the squealer tip.(2) studying influence of the relative move between the blade tip and endwall on heat transfer and clearance flow by the endwall slippage.(3) Studying the distribution of the film cooling effectiveness on both squealer tip and aquealer tip with fins for the slipping of endwall or not cases at the blowing ratios of 0.5, 1.0 and 1.5.The results show that:(1) increasing the attack angle caused the reduced the average heat transfer coefficient of the aquealer tip and the endwall slippage strengthened vortex flow resulting in changed distribution of heat transfer coefficients and the high averaged heat transfer coefficient.(2) the maximum value of the film cooling effectiveness appeared near the film cooling holes at blowing ratio of 0.5 and the maximum value appears near the suction surface area at the blowing ratio of 1.5.(3) the fin optimized the distribution of the cooling effectiveness of blade tip, resulting in the high averaged value. This effect was most significant at blowing ratio of 0.5. Endwall slip inhibited coolant lift off the tip surface and it was in favor of improving the cooling effectiveness. Finned tip increases the total pressure loss of the turbine cascade.