Numerical Investigation Of Spontaneous Tip Injection Coupled With Squealer On Tip Leakage In Axial Turbine

As a kind of power mechanical equipment,gas turbine plays an important role in the fields of energy generation and ship application in China.There is leakage flow in the tip clearance of the rotor,which has an important effect on blade circumferential load and oil consumption.Therefore,the suppression of gap leakage flow has always been a hot issue in the research of turbine.However,the potential of using methods of single inhibition and conventional design to inhibit tip leakage is close to the limit.In this paper,theoretical analysis and numerical simulation are combined to focus on the research of the suppression of turbine blade tip leakage flow by fluid coupling of spontaneous tip injection and tip squealer.At first,without considering the influence of leakage flow on the mainstream of the channel and using the low-speed plane cascade as the research object,the paper investigate the number of single row holes and the arrangement of several row Inhibit are to suppress the effect of tip leakage.Then,on the basis of the analysis.Spontaneous tip injection near pressure surface coupled with tip squealer is numerically studied using orthogonal experiment method to optimize jet parameters firstly and the matched composite passive coupling scheme were screened.Finally,obtain the result of the effect of leakage suppression better than that of the single control method.In addition,adding trench in the the former’s groove is proposed to obtain the effects of four different trench types and sizes on the clearance leakage.two typical blade profile of spontaneous tip injection coupled with one squealer and three typical blade profile of spontaneous tip injection coupled with double Squealer are using the method of three-dimensional numerical simulation studied the effect of tip leakage.Compared respectively with the corresponding pure pure spontaneous tip injection,pure squealer and pure blade model,we screen and obtain their gap leakage flow,mach number contours and streamline distribution and the leakage flow suppression effect and the blade load distribution,which lays the foundation for the design of better fluid coupling characteristics of blade profile and also has a deeper understanding of the fluidcoupling mechanism between the two passive suppression methods of Spontaneous tip injection and squealer.In the end,the actual conditions may affect the fluid coupling.Therefore,by using the method of three-dimensional numerical simulation,several typical factors of real operating condition,such as inlet temperature,incidence angle,and casing wall relative motion have been studied with the emphasis on gap leakage flow,mach number contours and streamline distribution and the leakage flow suppression effect and the blade load distribution.Finally,in a word the use of self emission fluid coupled model of flow and leaf top groove of the turbine tip leakage flow to suppress this idea has certain research value and potential,and to determine the research direction in the future research.