离心压气机错排叶栅扩压器性能研究

Research on Centrifugal Compressor Staggered Arrangement Cascade Diffusers

依据叶片设计的基本理论,在原设计单列圆弧叶栅扩压器的基础上,根据相似准则设计了一种新型的双列错排叶栅扩压器;同时利用NACA叶型又设计了另一种双列错排叶栅扩压器。随后重点对三种扩压器与离心叶轮相连后的结构性能进行了详细的三维粘性数值模拟研究,并对流场中的压力、速度、极限流线和熵分布情况进行了全面的分析。研究结果表明:基于NACA叶型的双列错排叶栅扩压器可以更好地利用叶轮出口的动能,从而提高叶轮-扩压器结构的效率;但若叶栅的叶型设计不合理,则会使总压比降低,效率反而降低,即叶型对错排叶栅扩压器的性能影响较大。

According to the blade design theory and similarity criterion, two new types of staggered arrangement double row cascade diffuser were designed. One is based on the original design of single arc blade profile of vaned diffuser, another is on the basis of NACA blade profile. By using 3D viscous numerical simulation, the research was focused on the structure performance of three kinds of different diffuser connected with the same centrifugal impeller, The characteristics of the flow field pattern were analyzed according to the distribution of pressure, speed, limited stream line and entropy. The numerical results show, for the staggered arrangement double row cascade diffusers based on NACA blade profile, it can more effectively utilize the kinetic energy of the impeller outlet, and enhance the structural efficiency. But if the blade profile is designed unreasonable, it will reduce the total pressure ratio, and decrease instead of increase the efficiency. Therefore, the blade profile has a great influence on the performance of the staggered arrangement cascade diffuser.