Accuracy analysis of unsteady numerical simulation methods for axial flow compressor

Taking Stage 35 single-stage axial compressor as model, the predictions obtained using the nonlinear harmonic, phase lag and domain scaling method were compared respectively with the results obtained using a conventional half annulus unsteady simulation and experiment. The purpose was to analyze the numerical accuracy and computational efficiency of the three methods. Numerical results indicated that the three methods can all achieve same accuracy level as the half annulus unsteady simulation in terms of time-averaged parameters of flow field, but the spectrum characteristics obtained by domain scaling method revealed significant differences due to the geometry scaling, especially the amplitude in fundamental harmonic. The precision of the phase lag method was higher than domain scaling method in the prediction of amplitude in fundamental harmonic, however, it was usually contrary in other harmonics. Furthermore, the unsteadiness predicted by nonlinear harmonic method can not achieve the same accuracy as the phase lag and domain scaling method.