Squeeze Film Dampers:
Effect of Central Groove on identified force coefficients
MAJOR APPLICATION: Attenuate vibrations and isolate the rotating components from
the engine structure
Sponsors: Pratt & Whitney Engines,
Objective: To assess the forced dynamic performance
of two parallel SFDs for various geometries and end conditions, and to develop
a SFD predictive code benchmarked against test data
Status: A SFD test rig is designed to sponsor
specifications, manufactured and assembled in the laboratory. The test rig is highly modular in
construction – the geometry, squirrel cage support stiffness, lubricant supply
arrangement and end conditions can be quickly reconfigured. A static loader enables
SFD operation on static off-centered positions. Electromagnetic shakers (500 lbf)
deliver dynamic excitations to the test structure along two orthogonal
directions. A data acquisition and control code controls the shakers and
acquires data from a multiple sensors.
Current Work
Test rig is assembled
and fully operational. Frequency domain parameter identification procedures are
developed. SFD added mass (inertia) and damping coefficients are identified for
two SFD land lengths, multiple support stiffnesses and active lubricant feeding
holes, lubricant flow rates and groove pressures, and open and sealed end
conditions. A computational FORTRAN® code using a finite element
formulation of the Reynolds equation is developed. The predictions of SFD added
mass and damping coefficients are benchmarked against experimental coefficients
TEST FACILITY
TEST RIG STRUCTURE
Updated Jan 21, 2011