A technique for reducing the vibration and noise from marine propulsors is examined theoretically and demonstrated experimentally. A single layer of elastomer is incorporated into a rotor to form a rotating vibration isolation mount. The mount isolates the rotor hub and shaft from the unsteady forces generated on the blades due to their interaction with circumferentially non-uniform, time-averaged inflow and turbulence. This results in reduced vibration and noise. Nonrotating isolated rotor transmissibility is well predicted with a simple lumped parameter rotor model for frequencies below the first bending mode of the blades. Tests performed under operational (i.e., rotating) conditions have shown that rotor isolation provides a reduction of up to 15 dB in transmissibility compared to an identical rotor without isolation.

Issue Section:
Technical Briefs
Keywords:
vibration isolation, noise abatement, structural acoustics, marine systems, lumped parameter networks
Topics:
Rotors, Vibration, Noise control, Elastomers, Vibration isolation
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Copyright © 2003
 by ASME
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