A computational method for complex-shaped hydraulic turbomachinery flow based on the immersed boundary method

Traditional numerical simulation techniques, such as sliding mesh, dynamic mesh, and others, have many limitations in dealing with flow simulation with the large-scale movement of solid boundaries, which is the case for simulating the flow of complex-shaped hydraulic turbomachinery such as propellers, pumps, and turbines. The immersed boundary (IB) method provides a new approach to solve the above-mentioned limitations. Therefore, this study proposes a sharp-interface IB method based on the level-set function that is suitable for simulating the flow through turbomachinery with complex geometries. This method is applied to actual three-dimensional numerical simulations of high-Reynolds number propellers using an in-house computational fluid dynamics solver. The results show that the proposed method can provide comparatively accurate predictions of unsteady load coefficients within the propeller flow passage and capture the correct propeller wake characteristics as well as the interaction between the propeller wake and free surface. This study is aimed at providing a theoretical basis and engineering reference for the application of the IB method in engineering numerical simulations.