基于拟压缩方法的叶片扩压器低速流场数值研究

摘要 发展了基于拟压缩方法的求解叶轮机械低马赫数流场的方法，研制了了时间推进方法对叶轮机械全流速范围流场的求解的计算程序，且对拟压缩因子的取值进行了讨论。通过对离心压缩机叶片扩压器的数值计算表明，本文发展的基于拟压缩方法能能够快速正确的预测叶轮机械内的低速流场；引入拟压缩方法是对时间推进方法的一个很好补充，使时间推进方法的应用范围得到了拓展。

Numerical Investigation of Low-Mach Number Flowfield Inside of Vaned Diffuser Based on the Pseudo Co

Abstract: Aim. To our knowledge, owing to the type of the flow governing equation system, the low efficiency of standard time-marching algorithm in solving the low Math number flows. We now explore a time marching code to solve the incompressible internal flow field of turbomachinery based on the pseudo compressibility method. In the full paper, we explain our exploration in some detail; in this abstract, we just add some pertinent remarks to listing the three topics of explanation. In the first topic, a universal N-S equation system is derived which can govern both high subsonic and low Mach number flow by a pseudo compressibility factor developed by Chorin. In the second topic, we mention that four step Runge-Kutta time-marching method with the central difference scheme is employed to resolve the N-S equations. Also in the second topic, we point out that how the optimal pseudo compressibility factor is determined. In the last topic, we give some numerical results and their analysis for a vane diffuser of a tested centrifugal compressor. The analysis of these results shows preliminarily that: (1) for the low Mach number flowfield, both efficiency and accuracy of the time marching algorithm based on the pseudo compressibility method is higher than that of the traditional time-marching algorithm; (2) the pseudo compressibility method is a compensator for the time-marching algorithm, and the application of the time-marching algorithm is extended by introducing the pseudo compressibility method.