Variable Mass Flow Rate And Temperature On The Performance Of The Cascade Effects Of Experimental Research And Numerical Simulation

With the increase of the turbine inlet temperature, the technique of high efficiency film cooling to decrease the blade surface temperature has become a hot topic of the turbine design. In this research, using a turbine cascade which has a single row of discrete film cooling holes on blade's leading surface and a single row of discrete film cooling holes on blade's suction side, a series of film cooled turbine cascade experiments are carried out in the high speed wind tunnel of China Gas Turbine Establishment. The test data at different cooling flux,different ejecting position,different cooling temperature was recorded. The experimental results showed that cooling flux has bigger influence on energy loss and smaller influence on exit flowing angle. Cooling temperature has small influence on both energy loss and exit flowing angle. The cooling jet's effect is limited in boundary layer when ejected from leading edge. When cooling jet ejects from suction side, it will introduce bigger mixing loss and results the separation of boundary layer.The numerical simulation of the experimental results mentioned above has carried out using the CFD software. The influence of vary grid number(fifty thousand,one hundred and twenty thousand,two hundred thousand,three hundred and fifty thousand,five hundred thousand),vary grid configuration(the length between grid outlet and blade trailing edge:0.5t,1.0t,1.5t),vary turbulence model(k-εmodel,k-εRNG model,k-ωSST model),vary boundary disposal method and vary discrete difference on 3-D numerical modeling precision has been researched. The numerical simulation method of cooled turbine has been calibrated and improved in terms of experimental results. A 3-D flowfield analysis tool which can deal the problem of cooling jet mixing has been developed.