多级离心压缩机级间静止部件气动特性与旋涡结构的数值研究

通过CFD技术对某型多级离心压缩机内的流动进行了数值模拟,重点研究了多级离心压缩机级间装置如回流器、两类弯道内气动特点及其旋涡结构的特征,旨在揭示气流经弯道与回流器后气动参数的变化规律.结果表明,不同位置的弯道对流动的影响是截然不同的.由于这些静止部件对流体的扰动,使次级动叶的进口来流工况点偏离设计值,易于造成整机气动性能的下降.因此,多级压缩机的动叶设计应对来流的不均匀性加以充分考虑.

Numerical investigation for aerodynamic performance of the stationary components and vortex structure inside a multistage centrifugal compressor

The numerical flow analysis in a multistage centrifugal compressor is presented.More importance is attached to the aerodynamic performance of the stationary components inside the compressor,such as deswirl cascade and two types of crossovers.The vortex structure inside the deswirl cascade is also studied to disclose its influence on the aerodynamic performance.Jameson central scheme with BaldwinLomax turbulence enclosure is applied to Reynold's timeaveraged NS equations.The numerical investigation indicates: the flow through those stationary components may be distorted,resulting in the deviation of operating condition for the downstream rotating impeller and in decrease of the total aerodynamic performance of the whole machine.The design of rotating impeller of multistage centrifugal compressor should fully take into account the upstream flow distortion.