【摘要】 论文以实际应用中出现破裂的向心涡轮为研究对象,研究导流叶片尾缘激波、导流叶片叶尖间隙泄漏流动以及导流叶片尾迹对转子叶片表面压力波动的干涉作用,定性确定这三种因素在转子叶片表面压力波动中所占比重大小,发现激波和导流叶片叶尖间隙泄漏流动所诱导的转子叶片压力波动位置。结果表明,激波和导流叶片叶尖间隙泄漏流动是导致转子叶片表面压力波动的主要因素;受向心涡轮叶轮进口形状的影响,激波只是和转子叶片前缘附近的吸力面发生作用,导流叶片开度减小,激波强度增大,转子叶片压力波动幅值明显增大;导流叶片叶尖和叶根间隙泄漏流动会导致转子叶片吸力面叶尖和叶根的压力波动明显增大,是转子叶片前缘叶尖发生高周疲劳的主要原因.更多还原

【Abstract】 A three dimension numerical simulation of the flow field in variable geometry turbine,suffered high cycle fatigue,was performed to research the aerodynamic interaction between the nozzle and rotor,which includes the clearance leakage from the nozzle,wake and the shock wave stood on the surface of the nozzle vane.And then the attention was focused on understanding the special locations affected respectively by three kinds of factors on the surface of the rotor.The results show that the shock wave and clearance leakage are the main reasons for rotor blade surface pressure fluctuation.The shock wave only affects the leading edge of the rotor blades because of the special blade shape.For close condition,the shock wave and the amplitude of the pressure fluctuations on the surface of the rotor is increased compared to that for open condition.In the regions near the tip and hub side on the suction surface of the rotor blade,the size of the pressure fluctuation is increased significantly by the influence of the clearance leakage.This may be one of the main reasons for the high cycle fatigue.更多还原