The pod propulsion systems are extensively used in polar ice-class ships to enhance manoeuvrability and propulsion efficiency. This study investigates the thermal-fluid-solid coupled dynamic performance of non-contact end-face seals under polar low-temperature conditions. Steady and dynamic fluid film models considering temperature-dependent seawater viscosity and density were developed based on the compressible Reynolds equation, and thermal-mechanical deformation of the seal structure was analyzed using the finite element method. Results show that low-temperature-induced thermal deformation reduces the fluid film thickness by approximately 13%, significantly affecting stiffness and damping. With decreasing temperature, the increasing seawater viscosity leads to enhanced principal stiffness coefficients but slightly reduces the damping coefficient, improving seal rigidity while weakening energy dissipation. Higher rotational speeds markedly improve both stiffness and damping, while greater pressure difference enhance damping—especially axial damping—thereby stabilizing the fluid film. Overall, the seal demonstrates superior dynamic stiffness and stability under low temperatures, high speeds, and moderate-to-high pressure differences. This work provides theoretical insights into optimizing structure and enhancing operational adaptability of end-face seals in polar pod propulsion systems.
Chen et al. (Sun,) studied this question.