Abstract: To explore the influence of high-pressure turbine with variable geometry on the entire turbine performance，a spherical end-wall VGT is used on the HPT of a two stage turbine，and a full three-dimensional numerical simulation is carried out on the two stage turbine. It turns out that the rotating of HP guide vane can adjust the specific enthalpy-drop and power of the LPT by modifying its inlet total temperature and mass flow. Rotation of HPT guide vane will make a big difference on the power of the LPT. The efficiency of LPT will decrease with HPT guide vane closing. Different rotating angles of HPT guide vane lead to different inlet angles of LPT，thus different fluid field and loss of LPT guide vane. The flow field in the downstream blade row will be less affected as its axial location further away from the adjustable guide vane of HPT.

Key words: Variable geometry turbine；Spherical end wall；Variable cycle engine；HPT&LPT matching；Adjustable guide vane

摘要： 为了研究高压涡轮变几何对涡轮整体性能的影响，对涡轮高压级进行球面端壁变几何改型，并对该涡轮的高、低压级流动进行了全三维数值模拟研究。结果显示:高压可调导叶旋转通过改变低压涡轮进口总温、质量流量来实现对低压涡轮比焓降和功率的调节，低压涡轮功率随可调导叶旋转将出现大范围的变化，低压涡轮效率随可调导叶的关闭会有所下降；高压导叶可调会改变低压涡轮进气角，进而影响低压导叶的流场结构和损失；随着轴向位置远离可调导叶，下游叶排内流场受可调导叶旋转的影响将减小。

关键词: 变几何涡轮；球面端壁；变循环发动机；高低压涡轮匹配；可调导叶