The purpose of the Squeeze-Film Damper node is to model the additional damping provided to the bearing through a squeezing action in the fluid film. Damping is modeled in terms of effective damping coefficients based on the analytical solution of the Reynolds equation in the film for a short length approximation. These coefficients are functions of damper dimensions, lubricant properties and the location of the journal in the damper as given below:
Here, μ is the viscosity of the lubricant,
R is the radius of the journal,
L is the length of the journal, and
C is the clearance between the journal and damper when the journal is concentric with the damper. Subscripts
2 and
3 refer to local
y and
z directions, respectively.
u2 and
u3 are the journal displacements in the local
y and
z directions, respectively.
is the eccentricity of the journal in the damper.
ε is the relative eccentricity with respect to the initial clearance between the journal and the damper,
ε =
e/
C.
