New Mathematical Models for Coefficients of Hydrodynamic Resistance to Rotation and Friction of Sliding Bearings of Ship Propulsion System for non Newtonian Lubricants

The boundary value problem for the Reynolds differential equations for the lubricating layer in the sliding bearings of ship power plants and auxiliary ship equipment is solved by the boundary variation method. As a result, analytical representations for hydrodynamic pressure, shear stresses, and integral characteristics of the lubricating layer were obtained, as well as their refinement, which considers the presence of a lubricating layer outside the working zone of the sliding pair. This made it possible to build new, easy-to-use mathematical models for the coefficients of rotational resistance and hydrodynamic friction of sliding bearings of the ship's propulsion system, considering the non-Newtonian properties of lubricants, that is, in the case of the dependence of dynamic viscosity on pressure and temperature. The obtained mathematical models consider the geometric parameters of bearings, operational parameters: relative radial clearance and relative eccentricity, angular velocity, as well as viscous characteristics of lubricants, in particular, dynamic viscosity and piezo coefficient of viscosity of lubricants. A criterion for the applicability of non-Newtonian lubricants for given operating modes of the sliding bearing has been developed, which uses the viscosity characteristics of the lubricants. The research results are illustrated in the form of tables and graphs.