A Novel Viscous Throughflow Model for Compressor Analysis and Its Application

Throughflow calculations are still an inevitable step in the aerodynamic design of compressors. The viscous throughflow model derived from Navier-Stokes equations can be more capable in predicting choked flow and capturing shock waves compared to the traditional methods. In this paper, authors further developed the inviscid model for a previously developed throughflow analysis method. To obtain the governing equations, three-dimensional Navier-Stokes equations combined with the Spalart-Allmaras turbulence model were circumferentially averaged with the assumption that the flow was circumferentially uniform. A viscous blade force and an inviscid blade force had been calculated. The Miller's correlations of deviation angle and loss were incorporated to model these forces. The governing equations are discretized by an explicit four-step Runge-Kutta scheme and solved by a time-marching finite volume method. Current model was verified through predicting the performances of a 1.5 stage fan. The agreements between the experiments and calculations are reasonably good. This throughflow model can predict quite similar flow patterns and radial profiles of some parameters compared to a CFD software, which shows the potential of this model. There are still some notable deviations between the results from throughflow analysis and that from CFD calculation. Future work is to improve the prediction of deviation angle and loss near the endwall regions.