Accession Number : ADA207532

Title :   KC-135R Rumble Investigation.

Descriptive Note : Final rept. Oct 86-Jan 88,

Corporate Author : DAYTON UNIV OH RESEARCH INST

Personal Author(s) : Drake, Michael L ; Davis, Dennis G

PDF Url : ADA207532

Report Date : 27 Feb 1989

Pagination or Media Count : 242

Abstract : The KC-135R is a modified KC-135A which has had, among other things, the engines changed from the J-57 to the new F-108-CF-100 engines. Shortly after the KC-135R began SAC flight operations, a noise problem perceived as a rumbling sound in the cabin area was found in various aircraft; i.e., Rumble. The Air Force, the aircraft manufacturer and the engine manufacturer studied the problem briefly developing a better definition of the general problem. The forcing function was determined to be the F-108 engine; however, the precise source of the noise and vibration, and the transmission path from the engine to the cabin were unknown. Keywords: Aircraft engine vibration; Low frequency vibration; Flight test; Acoustic intensity; Modal analysis; Engine vibration; Engine/airframe; Resonant coupling; Jet engines. (kt)

Descriptors :   *TANKER AIRCRAFT, *AIRCRAFT NOISE, *AIRCRAFT ENGINE NOISE, ACOUSTIC SIGNALS, AIR FORCE, AIRCRAFT, AIRCRAFT CABINS, AIRCRAFT ENGINES, AIRCRAFT INDUSTRY, AIRFRAMES, COUPLING(INTERACTION), FLIGHT, FLIGHT TESTING, INTENSITY, JET ENGINES, LOW FREQUENCY, LOW LEVEL, NOISE, PATHS, PRECISION, RESONANCE, SOURCES, TRANSMITTANCE, VIBRATION

Subject Categories : Transport Aircraft
      Jet and Gas Turbine Engines
      Acoustics

Distribution Statement : APPROVED FOR PUBLIC RELEASE