Effect of Gun Tube Evacuation on Free Field Blast Pressures and Comparison with Proposed Models

摘要

Since excess muzzle blast overpressures are adversely affecting artillery crew safety and performance, there is interest in developing a detailed understanding of the blast from guns, so that accurate computations may be performed and blast prediction techniques may be developed. The objective of this paper is to examine the influence of the precursor flow upon the propellant gas blast. To investigate the precursor effect, a 20mm cannon is evacuated to eliminate the air column forward of the projectile. Data taken from these rounds are compared with that from firings at ambient conditions. The precursor-propellant gas interaction is demonstrated to influence the blast wave development in the near field forward of the muzzle; however, beyond a distance of 25 calibers from the muzzle, the two cases are indistinguishable.