Investigations on the applicability of hydrostatic bearing technology in a rotary energy recovery device through CFD simulation and validating experiment

• The hydrostatic bearing was firstly introduced into the RERD
• The hydrostatic bearing favors for the establishment of fluid film lubrication in RERD
• The circular clearance regarded as fluid restrictor was optimized
• Experimental results are in accordance with CFD simulations

Based on the structural characteristics of the rotary energy recovery device, the hydrostatic bearing was established on both sides of the rotor. Effects of the hydrostatic bearing on the resultant force and fluid film thickness were investigated by the methods of computational fluid dynamics simulation and validating experiments. Simulation results indicate that resultant force rises linearly with the increase of both operating pressure and thickness difference between the upper and lower fluid films, indicating that there exists a cooperative function between the upper and lower fluid films which favors for the self-adjustment of film thickness and resuming the rotor to a stable lubrication state when the pressure changes. The circular clearance regarded as fluid restrictor was optimized in order to adjust the fluid film thickness rapidly and the best circular clearance is about 0.03 mm. The experimental results indicate that the practical resistance of the rotor can well be reflected by the changing trend of the experimental rotor speed at operating pressure from 0.1 MPa to 6.0 MPa, and is in good accordance with the theoretical resistance calculated by using the simulation results, verifying that the simulation model was reliable. This study provides an applied structure for improving the frictional state of the rotor and prolonging the working life of the device.