Effect of different turbulent lubrication models on the lubrication characteristics of water-lubricated rubber bearings at a high Reynolds number

Abstract

To study the lubrication characteristics of water-lubricated rubber bearings under high-Reynolds-number operating conditions, four different turbulent lubrication mathematical models are used. With these models, adopting the finite difference method, initially, the distributions of the Reynolds number, water film thickness, lining deformation, and film pressure are analyzed. Second, for the same models, the variation in the Reynolds number with the eccentricity is investigated. Third, the bearing capacity and maximum film pressure variation with the eccentricity, rotating speed, and clearance ratio for the four turbulent lubrication models are examined. The results show that the lining deformation and maximum film pressure of the above models are larger than those of laminar lubrication models, and according to the importance of descending orders, they are as follows: Aokihiro-Harada Masahiro turbulence model, Ng–Pan model, Constantinescu model, and Hirs model; the type of the lubrication model has a little effect on the Reynolds number. The bearing capacity and film pressure calculated by the turbulent lubrication models are much higher than those by the laminar lubrication model, and the laminar flow assumption is no longer applicable to the actual operating conditions of the water-lubricated rubber bearings at a high Reynolds number. Concurrently, the Aokihiro-Harada Masahiro turbulent lubrication theory is more accurate than the other three lubrication models. With the increase in the eccentricity and rotational speed, the bearing capacity and maximum film pressure increase non-linearly and approximately linearly, respectively. By contrast, with the increase in the clearance ratio, the bearing capacity exhibits a non-linear decrease, whereas the pressure increases approximately linearly.