Research on the propulsion motor cooling by the coupled flow field of unmanned underwater vehicles

Abstract

The unmanned underwater vehicle (UUV) plays a crucial role in ocean exploration and development. Enhancing the hydrodynamic performance of UUVs relies heavily on high-power density propulsion motors. The cooling technology employed for UUV propulsion motors is of utmost importance in further improving their power density and hydrodynamic performance. This study proposes a cooling system with an internal and external coupled flow field, inspired by the bionic shark fin structure, with an aim to replace the conventional cooling system that introduces external low-temperature seawater into the cooling water channel with a pump. To evaluate the effectiveness of our proposed cooling system, we establish an electromagnetic-fluid-thermal coupled model of the cooling system based on the internal and external coupled flow field model of the UUV and the electromagnetic model of the propulsion motor. Coupled simulation model shows that the proposed cooling system can effectively cool the propulsion motor, while the coupled flow field structure does not significantly increase the UUV resistance. Subsequently, we developed a prototype of the UUV propulsion motor and conducted testing to assess the performance of the coupled flow field cooling system. The results indicate that, although the speed-up of the UUV will rapidly increase the propulsion motor power, the proposed cooling system can adaptively and efficiently cool the propulsion motor at any velocities.