Analysis on discharge coefficients in FEM modeling of hybrid air journal bearings and experimental validation

Solving the Reynolds equation is an efficient method to simulate the performance of the hybrid air journal bearings, and the accuracy of the method is determined by discharge coefficients (Cd). The discharge coefficients in hybrid air journal bearings are different with those in flat and static air bearings due to the varied film thickness in the circumference and working condition in high speeds. Taking account of these effects, a new formulation on computing discharge coefficients is proposed on the basis of the previous research. Furthermore, the variations in the bearing load performance are investigated using the modified Cd and the associated FEM method, supported by well-designed experiments.