Study on mixed thermal-visco-hyerelastic hydrodynamic lubrication performance of water-lubricated rubber bearings in deep-sea environment

The deep-sea environment is characterized by high-pressure and low-temperature conditions, presenting significant challenges for equipment operating in deep-sea. To investigate the mixed thermal-visco-hyperelastic lubrication performance of water-lubricated rubber bearings (WLRBs) in deep-sea environment, this paper develops a mixed thermal-visco-hyperelastic hydrodynamic lubrication model (MTVHHLM). This model incorporates the effects of both the deep-sea high-pressure and low-temperature conditions, as well as localized temperature increases within the bearing, on the rubber material properties. In this study, the central fluid pressure distribution and temperature distribution predicted by the present model are validated by published experimental results, thereby confirming their accuracy. Furthermore, under the current simulation conditions, as specific pressure increases, the influence of seawater depth on the mixed thermal-visco-hyperelastic lubrication performance of WLRBs becomes more pronounced. As seawater depth increases, the rise in seawater pressure reduces fluid shear stress. However, this effect is partially offset by the decrease in ambient temperature. Consequently, the variations in friction coefficient and heat-flux caused by fluid shear with increasing seawater depth are relatively minor. The variation in viscoelastic dissipation and actual contact shear is the primary factor influencing the total friction coefficient and heat-flux as seawater depth increases. Furthermore, in deeper seawater environments, WLRBs can achieve a state closely resembling elastohydrodynamic lubrication at relatively low speeds. This study offers a valuable reference for the application of WLRBs in deep-sea environments.