Accession Number:

ADA199695

Title:

An Examination of Controlled Vortex Drag Using Stepped Afterbodies from M = 0.5 to 3.0

Descriptive Note:

Final rept. Feb 1986-Sep 1988

Corporate Author:

AIR FORCE ARMAMENT LAB EGLIN AFB FL

Report Date:

1988-09-01

Pagination or Media Count:

7.0

Abstract:

A comparison of the zero lift drag coefficients of a stepped base projectile to flat base and truncated boattail base projectiles is presented. Three model configurations were investigated during the test program. These included an experimental 20mm round with a 7 12 deg., truncated boattail base, a round modified with a flat base, and a round modified with a stepped base. All of the projectiles were tested at sea level conditions in an indoor ballistic free-flight facility. This paper discusses the aerodynamic experiment and the data obtained. Results show that the zero lift drag coefficient of the stepped base projectile was less than that of the flat base round for the subsonic Mach number range and approximately the same for the transonic and supersonic ranges. However, the stepped base projectile produced zero lift drag greater than that of the boattail round at each Mach number. Keywords Base drag Separated flow projectile afterbody Ballistic testing.

Subject Categories:

  • Guided Missile Dynamics, Configurations and Control Surfaces
  • Fluid Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE