Accession Number:

ADA270535

Title:

A Parametric Investigation of Muzzle Blast

Descriptive Note:

Final rept. Oct 1991-Sep 1992

Corporate Author:

ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD

Report Date:

1993-09-01

Pagination or Media Count:

46.0

Abstract:

Weapons that vary greatly in their bore lengths are fired over a wide range of projectile velocities. Pressure transducers are located from 15 to 400 calibers from the muzzle and at 30-degree increments around the gun. The investigation yields a detailed picture of the flow field, as displayed by overpressure traces. Comparisons of the overpressure data with an older established prediction method show better agreement for the measured points nearer to the muzzle. Here, a scaling approach combined with a parametric least squares investigation is used to model the peak overpressure, which asymptotically approaches the far field behavior yet gives the nonlinear behavior nearer the muzzle. Using the shock wave expression, which depends on the fitted peak overpressure results, an expression for the time of arrival is obtained which in turn is fitted to the time of arrival data. The positive phase duration is then obtained by subtracting the time of arrival from the zero pressure point of the wave, which is traveling at the approximate speed of sound. The shape of the positive phase of the wave is then assumed to correspond to a Friedlander wave. Assuming the shape, an expression for the impulse of the positive phase is obtained that depends on the fitted peak overpressure and the value of the positive phase duration. The parameters describing the positive phase duration are then fitted by using the impulse data. In summation, the physics of the blast wave is used to construct the time of arrival, positive phase duration, and impulse models. Fluid dynamics, Impulse noise, Muzzle blast, Noise management, Overpressure.

Subject Categories:

  • Ammunition and Explosives
  • Guns
  • Explosions
  • Acoustics
  • Fluid Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE