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.