Project Title:

Acousto-Fluidic Noise Generators for Aircraft

02.12-3077
Acousto-Fluidic Noise Generators for Aircraft
Component Structure Testing
Defense Research Technologies, Inc.
354 Hungerford Drive
Rockville
MD
20850
Allen B.
Holmes
(301-762-3077)
LaRC

Abstract:

Current noise generators now in use by the NASA-LaRC Acoustic Research Facility are
electro-mechanical devices which operate at low temperatures (70 F) and produce noise
evels up to 168 db. Since testing of advanced aircraft structures and materials to
noise levels up to 190 db at elevated temperatures is required, this project is examining
the technical feasibility of using fluidic oscillators to generate both narrow-band
(constant frequency) and broad-band noise using high temperature (1800 F) propellant
gas flows to generate noise in the 190 db power range. In the present state-of-the-art,
however, fluidic sound generators are miniature devices which have been operated
at low pressures and flow rates to produce sound pressure levels of approximately
130 db.
The Phase I effort will survey fluidic devices for use as hot-gas noise generators
in the Acoustic Research Facility. The results will be used to assess the feasibility
of scaling up oscillator designs to generate the desired noise power levels.

Potential Commercial Application:

Potential Commercial Applications:  The applications could be in testing advanced
structures and materials for supersonic aircraft.