A COMPARATIVE STUDY BETWEEN A REYNOLDS EQUATION (WITH DISCRETE MASS INJECTION) AND 3D NAVIER-STOKES EQUATIONS WITH APPLICATION TO ACTIVELY LUBRICATED HYBRID FLUID FILM BEARINGS
Active lubrication of hybrid fluid film bearings through external pressurization is an enabling mechatronics related technology providing a means of controling and enhancing bearing performance. The prediction of static and dynamic forces developed in such bearings has been accomplished previously through solution of a modified Reynolds equation (MRE) wherein lubricant injection ports were modeled as mass sources with parabolic velocity profiles imposed at the injector/thin film interface. In this paper, the simplifying assumptions of the MRE are explored through a comparative study of MRE results and higher-fidelity numerical solutions of the 3D Navier-Stokes equations (NSE). The results examined are pertinent to mechatronic applications, namely static forces and linearized dynamic coefficients. Pressure and velocity fields are also compared to evaluate the propriety and effect of MRE assumptions, that may account for discrepancies between MRE and NSE.