Accession Number : ADD009791

Title :   Airfoil Vibration Test Apparatus.

Descriptive Note : Patent,

Corporate Author : DEPARTMENT OF THE AIR FORCE WASHINGTON DC

Personal Author(s) : Jones,Carmen B

Report Date : 21 Sep 1982

Pagination or Media Count : 7

Abstract : This report describes an apparatus for inducing high frequency out-of-phase, vibrations in adjacent span-wise panel portions of a plate type structure, such as an airfoil blade of a gas turbine engine. The apparatus includes a novel bifurcated duct for conducting and directing two out-of-phase streams of gaseous flow, and a uniquely structured air chopper which generates the two out-of-phase gaseous streams. The duct has an upstream end with which the output of the air chopper is in communication, and a stepped-down downstream end at which the airfoil blade(or other plate type structure specimen that is to be tested) is held, supported, and positioned in a chord-wise direction, such that the two out-of-phase gaseous streams impinge upon, and induce the same high frequency vibration in, two preselected, adjacent, span-wise panel portions of the specimen, thereby the panel portions vibrate out-of-phase. (Author)

Descriptors :   *Patents, *Vibrators(Mechanical), *Blade airfoils, *Test equipment, *Fatigue tests(Mechanics), *Gas turbines, Compressor blades, Bending stress, Impingement, Gas flow, Vibration, Strain rate, Failure(Mechanics)

Subject Categories : Test Facilities, Equipment and Methods
      Mechanics
      Jet and Gas Turbine Engines

Distribution Statement : APPROVED FOR PUBLIC RELEASE