Numerical analysis on the dynamic behavior of the water-lubricated bearing of the energy recovery turbocharger during start-up

The dynamic behavior of the water-lubricated bearing of the energy recovery turbocharger during start-up is investigated. Rough surfaces of the bearing are characterized by using the Weierstrass-Mandelbrot function. The hydrodynamic pressure is obtained by solving the average Reynolds equation with the finite difference method. Moreover, the asperity contact force is calculated by the Greenwood-Tripp contact model. The results show that the hydrodynamic force increases suddenly and the asperity contact force decreases sharply during the initial stage of the start-up process. The reduction in acceleration time leads to a decrease in the asperity contact force and time. Meanwhile, the increase in radius clearance leads to a sharp increase in the hydrodynamic force and a sharp decrease in the asperity contact force.