Extending the Validity of Existing Squeezed-Film Damper Models with Elongations of Surface Dimensions
T. Veijola, A. Pursula and P. Raback
Helsinki University of Technology, FI
Keywords: compact model, gas damping, Reynolds equation, squeezed-film damper
Border flow effects in squeezed-film dampers having a gap separation comparable with the surface dimensions are studied with 2D and 3D FEM simulations and with analytic models derived from the linearized Reynolds equation for small squeeze-numbers. Surface elongations are extracted with 2D FEM simulations for 1D squeezed-film dampers for variable surface topologies for both linear and torsional modes of motion. To model 2D squeezed-film dampers, these elongations are used directly in the compact models, and the results are verified with 3D FEM simulations. FEM simulations show that a simple surface-elongation model gives excellent results, and extend the validity range of existing compact models. To improve the model, drag forces acting on the upper surface and the sidewalls are approximated with simple equations based on FEM simulations.
Nanotech 2004 Conference Technical Program Abstract