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本文针对1+1对转涡轮1.5级不同时序位置进行了非定常数值计算,结果表明,通过改变低压级导叶时序位置,1+1对转涡轮1.5级在较差时序位置仍可获得较高时均效率.在分析涡轮内部流场时,首先,发现1+1对转涡轮高压级动叶的尾迹在低压级导叶内的演变规律与常规涡轮(拉伸、剪切、扭转最后聚集成一团)有所不同,尾迹一般呈现由细渐粗的线状分布特征,该特征有利于涡轮时均效率的提高;其次,发现尾迹与二次流两类低能流体迁移规律的不同导致时均效率随时序位置变化出现双峰值现象;最后,发现改变时序位置时,低能流体对下游导叶前25％轴向弦长叶表非定常力有所影响,且低能流体越强非定常力变化越大,后75％轴向弦长叶表非定常力基本不受时序位置影响.“,”This paper presents unsteady research on different clocking positions of 1+1 counterrotating turbine 1.5-stage.The results show 1+1 counter-rotating turbine 1.5-stage can still have better time-averaged efficiency in the bad clocking position.When we focus on the specific flow field of turbine,as the special space distribution of low pressure stage vane,evolution principle of wake induced by high pressure stage rotor appears linear distribution from thick to thin in the low pressure stage vane's passage,differing from traditional turbine's evolution characteristics which are tensile,shear and torsion finally gathered into a ball,while the linear distribution characteristics are beneficial to the promotion of time-averaged efficiency.Additionally,different flow principles between wake and secondary flow are found,which causes the double-peak phenomenon.Finally,when clocking positions are changed,downstream vane blade loading of forward 25％ axial chord is influenced by low-momentum fluid and the blade loading fluctuates more fiercely as the low-momentum fluid accumulates increasingly,while blade loading of afterward 75％ axial chord is almost unchanged with the clocking positions varied.