Investigation of the unsteady flow of a transonic compressor using the nonlinear harmonic method

In this paper, the nonlinear harmonic method implemented in Fine/Turbo CFD code has been used to analyze the unsteady flow field in a transonic compressor. The numerical accuracy and computational efficiency of this method have been demonstrated by comparing its predictions with experimental data and conventional time-domain unsteady simulation for the test case. The rotor-stator interactions are studied in detail to improve the understanding of the flow physics involved. The deterministic stresses in the nonlinear harmonic method have also been compared to the time-domain unsteady postprocessing results to analyze distinct sources of unsteadiness. For the present case, the nonlinear harmonic method can not only capture the unsteady results satisfactorily, but also gain a significant computational advantage over conventional unsteady method.