无导叶对转涡轮三维流场数值分析

1引言近年来,研究者在1 1/2对转涡轮设计方法、对转涡轮实验台、实验件的设计加工以及对转涡轮的数值模拟方面进行了大量的工作1~8]。在1 1/2对转涡轮中,一方面由于两转子对转使叶排相对转速大幅增大,约为传统涡轮的两倍;另一方面,高压动叶在结构上与传统的渐缩式流道涡轮叶栅

Three-dimensional numerical investigation of vaneless counter-rotating turbine

In order to reveal the flow characteristics in a VCRT, a three-dimentional, viscous, steady CFD analysis was performed for investigating the turbine performance. Results show that the performance of this VCRT basically reaches the original objective, which indicates that a convergent-divergent blade passage in the high pressure rotor and a convergent-divergent meridian plane of the VCRT are suitable for the VCRT. All of these blade rows of the VCRT, especially high pressure rotor, need much more optimization. The efficiency of the VCRT can be improved through some optimized methods, such as blade curving, throat location adjusting, and so on. The results of the numerical simulations also show that the pitch-averaged Mach number of the outflow of the high pressure rotor is about from 1.4 at the hub to 1.6 at the shroud. The strength of oblique shock waves is strongest on the midspan in the trailing edge of the high pressure rotor. However, it is weaker on the hub and the shroud. Meantime, the results also indicate that the performance of the VCRT will decrease with the increase of the outlet pressure. The performance of the high pressure rotor is retained with the change of outlet pressure. However, performance of the low pressure rotor is greatly influenced with the change of outlet pressure.