RESPONSE OF AN OPEN ENDS SQUEEZE FILM DAMPER TO LARGE AMPLITUDE IMPACT LOADS
This paper presents measurements of the transient response of a test SFD due to an impact load of increasing amplitude. The SFD test rig replicates a damper-squirrel cage configuration in a commercial jet-engine. The test rig consists of an elastically supported bearing with a squeeze film section having a single film land length L=25.4 mm, diameter D=125 mm and a nominal radial clearance c=0.213 mm. The film land has its ends open to ambient conditions. Data was collected for six sets of an impact load of increasing amplitude, 0.5 kN up to 3.2 kN (FMAX/(LD)=1.5 – 10 bar), that produced transient displacements with peak amplitude as large as 93% of the radial clearance. The experiments intend to reproduce operation of a rotor-bearing system while experiencing a hard landing.