Sfdflexs Computational Analyses of Squeeze Film Dampers
The TAMU Turbomachinery Research Consortium funded the development of computational analysis programs for squeeze film dampers (SFDs)
calculates fluid film forces and damping force coefficients (Ctt,Crt) in finite length squeeze film dampers executing circular centered motions (1986)
calculates instantaneous fluid film forces for arbitrary journal motions and circular centered orbits in multiple-(flexure) pad integral squeeze film dampers (1996).
Analysis: The fluid flow
in the squeeze film lands is described by Reynolds equation for generation of
the hydrodynamic squeeze film pressure due to arbitrary motions of the damper
journal center.Flow relations for end seals, i.e., local
seal: end seal without large axial groove. global
seal: end seal with large axial plenum.
Flow model: Laminar and isothermal flow
Governing Equations: Reynolds equation
Numerical method of solution: finite elements
Limitations and Restrictions: Isothermal squeeze film dampers without fluid inertia
Cavitation model: Gumbel condition (chop negative pressures) or Reynolds condition (dP/dx=0) at cavitation inception zone
Input- MS Excel®
Graphical User Interface - worksheet
Output - MS Excel® Graphical User Interface - worksheet - Field data files for plotting pressure and film thickness as Z=Z(X,Y) surfaces.
Language: FORTRAN77 Source code provided.
Availability: Supplied to industrial members of TAMU Turbomachinery Research Consortium free of charge
Other software based on approximate solutions to analytical models:
calculates the damping and inertia force coefficients for finite length squeeze film dampers (SFDs) executing circular centered motions within the bearing clearance. The model includes dampers with open ends and (locally) sealed ends with asymmetric discharge coefficients.
calculates the linearized damping and inertia force coefficients for finite length open ends squeeze film dampers (SFDs) executing small amplitude motions about an equilibrium position within the bearing clearance.
approximate solution to flow equations including fluid inertia. Accurate Correction
factors to long SFD model are given in closed form. Fully Developed, laminar
isothermal-isoviscous flow model
Governing Equations: Continuity and averaged-inertia momentum equations for squeeze film flow. Flow relations for end seals (local type).
Cavitation model: cut negative pressures
Limitations and Restrictions: Isothermal SFDs with squeeze film Reynolds numbers (Res) < 20. Full film or pi-film cavitation models
Input- MS Excel® Graphical User Interface - worksheet
Output - MS Excel® Graphical User Interface – worksheet: Table of force coefficients vs. journal orbit radius or journal static center.