Accession Number : ADA018747

Title :   The Impact Pressure Distribution of a Hypervelocity Raindrop.

Descriptive Note : Technical rept.,

Corporate Author : ARMY MISSILE RESEARCH DEVELOPMENT AND ENGINEERING LAB REDSTONE ARSENAL ALA GROUND EQUIPMENT/MATERIALS DIRECTORATE

Personal Author(s) : Mullinix,B. R. ; Ranson,W. F. ; Swinson,W. F.

Report Date : 22 SEP 1975

Pagination or Media Count : 51

Abstract : The theory relating the impact pressure on the surface of a solid to the optical holographic fringe patterns is presented. The experimental system used to obtain the fringe patterns is presented and discussed. A water jet gun was used to obtain the hypervelocity water drop impacts, and a discussion of its validity as a simulation technique is discussed. The impact velocity of the jet was measured by breaking two laser beams a known distance apart, and was found to be 4900 ft/sec. The impact pressure distribution was determined and the maximum pressure was found to be at the center of impact. A ruby laser was used to illuminate the jet, and the 10 photographs taken at 10-microsecond intervals are presented. The variation in the size of the pressure zone as a function of time is shown. The impact pressure as a function of time is presented graphically.

Descriptors :   *Hypervelocity impact, *Water impingement, *Rain erosion, Raindrops, Impact, Radomes, Guided missiles, Ceramic materials, Holography, Ruby lasers, Windows

Subject Categories : Electrical and Electronic Equipment
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE