The damper stiffness and damping may be used to size the dimensions for a suitable damper design. After the damper is sized, then a full nonlinear analysis must be performed to determine its suitability.
For the steady state response, the following table summarizes the equivalent stiffness and damping for the cases of circular synchronous motion about the origin and pure radial motion with no precession for the conditions of cavitation (pi film) and no cavitation (2pi film).
Note that for the circular synchronous motion, the equivalent stiffness term is a highly nonlinear function of eccentricity and may lead to a nonlinear jump phenomenon under high rotor unbalance. Caution must be taken while designing the damper, since it can significantly either improve or degrade the dynamic characteristics of the rotor system.
See also Squeeze film damper.
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