Accession Number:

ADB000431

Title:

Wind Tunnel Study of Base Drag Reduction by Combustion of Pyrotechnics

Descriptive Note:

Corporate Author:

ARMY BALLISTIC RESEARCH LAB ABERDEEN PROVING GROUND MD

Report Date:

1974-10-01

Pagination or Media Count:

91.0

Abstract:

It is well known that tracer rounds have longer ranges than comparable nontracer ammunition, and the ballistician seeks ways to degrade the tracers ballistics to match the conventional round. Presumably the tracer reduces base drag by addition of heat and mass into the near wake of the projectile. Wind tunnel experiments conducted with well-defined gases at metered rates of injection showed that a hot, low-molecular weight gas would be the better drag reducer. It was also suggested that combustion in the near-wake could be advantageous. Fuel-rich mixtures of magnesium and inorganic oxidizers were investigated in this report as such gas generators designated fumers. The excess magnesium in such mixtures is to be the hot, low-molecular weight gas. Wind tunnel tests were performed at the Naval Ordnance Laboratory to see if fuel-rich magnesium propellants reduced base drag. These tests showed reductions on the order of fifty percent in combination with oxidizers that burn slowly enough to be used in small arms applications. The base drag reduction was also proportional to the quantity of excess fuel in the mixtures. Ignition of mixtures containing over forty percent by weight magnesium was impossible for all oxidizers tested.

Subject Categories:

  • Pyrotechnics
  • Ballistics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE