Accession Number:

AD0827935

Title:

MOIRE PATTERN TECHNIQUE FOR THE DETECTION OF SHOCKWAVES,

Descriptive Note:

Corporate Author:

NAVAL ORDNANCE LAB WHITE OAK MD

Personal Author(s):

Report Date:

1968-01-05

Pagination or Media Count:

25.0

Abstract:

An optical means of detecting and recording the structure of shockwaves formed in air is presented. The system is based upon the use of a special case of moire fringes and approaches the sensitivity usually associated with Schlieren type optical instruments. It has, in addition to a high sensitivity, a ruggedness and ease of use which makes it suitable for field-type applications. The moire pattern technique presented here is, for a specific piece of equipment, theoretically capable of sensing a 0.01 density change in air at atmospheric pressure and corresponds to a pressure differential of the order of 0.003 psi about 0.2 millibar. Pictures showing a pressure differential of the order of 0.08 psi 5.4 millibars have been made. No special attempts were made to record smaller pressures. Author

Subject Categories:

  • Explosions

Distribution Statement:

APPROVED FOR PUBLIC RELEASE