中文摘要：

为了有效减少当前航空发动机轴流涡轮导向器的叶片排数，对多级无导叶对转涡轮的气动设计方法展开了研究。给出了该类型涡轮的基本结构和命名方法，介绍了使用该涡轮的发动机热力循环模拟和性能计算流程，提出了能够改善动叶进口预旋、提高级载荷和效率的设计方法。完成了一个由4排锥形动叶构成的高负荷多级无导叶对转涡轮气动设计，设计点总压比和总效率的数值模拟结果分别为10．4和91．2％，验证了设计方法的有效性。

英文摘要：

The aerodynamic design method of multistage vaneless counter-rotating turbines is investigated to effectively and efficiently eliminate vanes between rotors. The turbine configuration and naming convention are provided, as well as a general process of determining the thermodynamic parameters of each stage. The aerodynamic design method that includes improving the inlet swirl, stage loading and efficiency for vaneless turbine stages is illustrated and applied to a multistage vaneless counter-rotating turbine consisting of 4 tapered rotor blades. The 3D viscous numerical results show that the total pressure ratio of 10.4 and isentropic total-to-total etficiency of 91.2% are obtained, achieving the initial design objective well.