Hybrid unstructured mesh generation method and flow analysis for turbomachinery

This paper proposes a hybrid unstructured mesh generation method for turbomachinery simulations, aiming to overcome the limitations of conventional approaches in geometric adaptability, size control, viscous boundary-layer resolution, and automation. First, a hybrid surface representation framework is constructed, in which the discrete surface representation serves as the background mesh for size control, while the continuous surface representation defines the geometric boundary for mesh generation. Subsequently, a unified topological data structure is established for the discrete representation, continuous representation, and mesh model. For the complex geometric configurations of turbomachinery, feature recognition and local mesh refinement techniques are developed, and the size function is defined on the optimized background mesh. In addition, an efficient size-function smoothing strategy is proposed to ensure a smooth transition between regions with different mesh densities. Finally, numerical simulations are carried out for several representative turbomachinery cases, and the predicted results are compared with the experimental data as well as those obtained using the commercial software packages CFD-ICEM and Pointwise. The results indicate that the proposed method significantly outperforms CFD-ICEM in terms of mesh generation efficiency, provides higher mesh quality than Pointwise, and shows good agreement with experimental data.