Steady state characteristics of an adjustable hybrid gas bearing - Computational fluid dynamics, modified Reynolds equation and experimental validation

To include the effect of external pressurization in hybrid gas bearings an extra term is added to Reynolds Equation to accommodate the gas jet. Two cases are considered: cylindrical and annular flow profiles. Validation of theoretical results obtained using the modified version of Reynolds equation for compressible fluid against computational fluid dynamics (CFD) model is presented in terms of pressure and flow rate considering pressurization levels, journal eccentricities and angular velocities. Correction factors for the jet discharge coefficients are necessary and calculated added by CFD model. By introducing such coefficients into the modified Reynolds equation, good agreement with experiments is achieved in terms of journal equilibrium position and resulting aerodynamic forces.