A complete rotor-stator coupling method for frequency domain analysis of turbomachinery unsteady flow

摘要

The paper presents a rotor-stator coupling method for analyzing unsteady flow field within multi-blade row turbomachines using a frequency domain method. The coupling method is called time and space mode decomposition and matching method. It is based upon coordinate transformation and Fourier transformation to extract relevant time and space modes represented by frequency of unsteadiness, nodal diameter and Fourier coefficients. Detailed procedures together with relevant formula are established to identify the matching time and space modes across an interface and calculate corresponding mode coefficients. The mode coefficients are then matched across an interface with the use of a one-dimensional non-reflective implementation. To verify the correctness and effectiveness of the proposed interface treatment, a transonic compressor was used as a test case. The unsteady flow field within it was analyzed using a time domain time marching method to obtain the results as a reference. Then various frequency domain solutions with different resolution of unsteady frequencies were performed. Comparison of amplitude of different static pressure harmonics between frequency domain solutions and the reference time domain solution was made and discussed. (C) 2017 Elsevier Masson SAS. All rights reserved.