Comparison among three models for compressor internal flow

In order to simulate the flow of compressor better, mixing plane method, harmonic balance method and phase lag method for CFD of compressor internal flow were implemented into an inhouse finite volume code. Taking NASA Stage 35 compressor model as an example, results of three methods were compared with each other. Result indicates that, phase lag method ranks highest in terms of accuracy and mixing plane method ranks lowest; the result of phase lag method is as accurate as the result of half annulus simulation of the flow with the dual time stepping method, and a factor of 20 speedup could be achieved; compared with mixing plane method, harmonic balance method can simulate unsteady interference between rotor and stator and global parameters variation in inlet and outlet accurately; when the harmonic order is set more than or equal to 5, the result of harmonic method does not vary with the harmonic order and matches well with the result of phase lag method; computational efficiency of mixing plane is much higher than the other two methods, computational efficiency of phase lag method is nearly equal to harmonic balance method with a harmonic order of 5.