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.