Efficient Modeling of an Axial Compressor with Swirl Distortion

This paper presents a satisfactory numerical strategy to reliably evaluate the three-dimensional large-scale flow feature of multistage axial compressors in response to complex swirl distortion with acceptable computational cost. Under the theoretical framework of the body force method, the guide vanes of a swirl distortion generator and the multiple blade rows of a two-stage low-speed axial compressor are described by distributed source terms instead of a complex body-fitted grid approach. The key flow structure of the paired swirl generated by the swirl generator and the main distributions of flow angle at the rotor outlet of the first stage captured by the model agree well with experimental results, demonstrating the effectiveness of the numerical strategy. Additionally, the interaction process between the steady-state paired swirl and the compressor is clearly revealed by the study. The intensity of the swirl distortion can be greatly reduced after passing through the axial compressor. However, the swirl has a significant impact on the local blade loading of the first stage, which induces the mass flux nonuniformity as well as total pressure and total temperature distortion. The combined total pressure and total temperature distortion is significantly attenuated near tip and slightly enhanced near hub as it moves through the second stage.