Patents Assigned to 501 Nordam
  • Jet engine noise reduction system
    Patent number: 5060471
    Abstract: A noise reduction system for a jet engine including a tubular exhaust shroud affixed to the engine through which engine exhaust gases pass, porous acoustical lining affixed to a substantial portion of the internal circumferential surface of the shroud, a chamber in contact with the acoustical lining outer surface and a controllable source of air pressure affixed to the chamber to control the passage of air through the acoustical lining to thereby vary the acoustical absorption properties of the lining.
    Type: Grant
    Filed: February 2, 1990
    Date of Patent: October 29, 1991
    Assignee: 501 Nordam
    Inventor: Delbert W. Torkelson