Accession Number : ADD016157

Title :   High Damping Limp Propeller.

Descriptive Note : Patent, Filed 30 Sep 92, patented 14 Dec 93,

Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON DC

Personal Author(s) : Maga, Lawrence J

Report Date : 14 Dec 1993

Pagination or Media Count : 17

Abstract : A limp propeller for underwater use with a high mechanical damping ability to absorb so-called broadband vibration noise is comprised of a fabric-like material, preferably made of braided high tensile strength material such as fiberglass or graphite fibers. The fabric is devoid of any stiffening plastic or epoxy matrix material. Rather a flexible matrix material having relatively large hysteretic losses when deformed cyclically in place of the stiffening plastic or epoxy matrix. or no matrix material at all is used in the present invention. The flexible matrix material or the complete absence of any matrix material renders the propeller blade relatively limp to flexure, thereby reducing its acoustic radiation damping or radiation efficiency.

Descriptors :   *PATENTS, *MARINE PROPELLERS, ACOUSTICS, BLADES, BROADBAND, DAMPING, EFFICIENCY, FABRICS, FIBERGLASS, FIBERS, GRAPHITE, INVENTIONS, LOSSES, MATRIX MATERIALS, NOISE, PLASTICS, PROPELLER BLADES, RADIATION, STIFFENING, TENSILE STRENGTH, UNDERWATER, VIBRATION

Subject Categories : Marine Engineering

Distribution Statement : APPROVED FOR PUBLIC RELEASE