Accession Number : AD0749389

Title :   Reflections of Weak Shock Waves from Acoustic Materials,

Corporate Author : DEFENCE RESEARCH ESTABLISHMENT VALCARTIER QUEBEC

Personal Author(s) : Cloutier,M. ; Devereux,F. ; Doyon,P. ; Fitchett,A. ; Heckman,D.

Report Date : 25 FEB 1971

Pagination or Media Count : 5

Abstract : A number of materials having good acoustic absorption properties have been tested in order to determine their relative effectiveness in attenuating weak high-frequency shock waves propagating in atmospheric air. Weak shock waves with an N-wave configuration of about 110-microsec duration were generated by rifle bullets flying 2400 ft/sec over samples of acoustic material supported on a metal plate, and the details of the reflection of these waves at the surface of the various materials were monitored by using shadowgraph-schlieren photographic techniques and pressure transducers. The urethane materials available gave a high amount of surface reflection compared to fiberglass materials of similar density. The least surface reflection was obtained with very low density (less than 1.0 lb/cu.ft fiberglass). (Author)

Descriptors :   (*HYPERSONIC TEST VEHICLES, SHOCK WAVES), REENTRY VEHICLES, HYPERSONIC CHARACTERISTICS, ACOUSTIC IMPEDANCE, TEST METHODS

Subject Categories : Guided Missile Reentry Vehicles
      Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE