Global Magnetic Field Distribution and Open Water Hydrodynamic Performance of a Flux-Modulated Rim-Driven Thruster

In order to improve the compression resistance and torque density of rim-driven thruster (RDT) to cope with complex and harsh deep-sea conditi ons, a flux-modulated RDT (FM-RDT) is proposed. This RDT uses a flux-modulated machine (FMM) as the driving machine, which utilizes a modulation ring to realize pressure protection in the deep sea and realizes the high-torque drive through the magnetic field modulation effect. The subdomain model is established in the air-gap and permanent magnet regions, and the permeance network (PN) model is established in the ferromagnetic regions. The nonlinear hybrid analytical model (HAM) of global magnetic field of FM-RDT is developed by combining the two models with boundary magnetic flux. The calculation results of HAM are compared with the finite element method (FEM), and the torque and magnetic saturation performance of the structure are analyzed. In addition, the open water hydrodynamic performance of FM-RDT is simulated and analyzed by using the computational fluid dynamics (CFD) method. The results show that the FM-RDT has a wider operating range and speed regulation range, and it is more suitable as the thruster for low-speed and heavy-duty deep-sea underwater vehicles.