A Design Methodology for the Prediction of Squeeze Film Stiffness and Damping Characteristics in Hybrid Journal Bearings under Pulsatile Load Conditions

A theoretical investigation into the prediction and measurement of squeeze film stiffness and damping for double hole entry hybrid journal bearings has been undertaken together with a review of previous work to identify critical bearing parameters. The analysis used a partial differentiation of the Poiseuille and Hagen-Poiseuille flow equations to develop a mathematical model for the bearing squeeze film. A novel transfer function between bearing displacement and load enabled bearing stiffness and damping coefficients to be obtained from the subsequent frequency response characteristics. Parameter maps were developed from the model for both stiffness and damping and show that the squeeze film stiffness is a function of bearing clearance and squeeze film pressure and is independent of fluid viscosity with damping being a function of viscosity and clearance.