Accession Number : ADA117311

Title :   Flight Instabilities of Spinning Projectiles Having Non-Rigid Payloads.

Descriptive Note : Conference paper,

Corporate Author : ARMY ARMAMENT RESEARCH AND DEVELOPMENT COMMAND ABERDEEN PROVING GROUND MD CHEMICAL SYSTEMS LAB

Personal Author(s) : Miller,Miles C.

Report Date : 18 JUN 1982

Pagination or Media Count : 15

Abstract : A laboratory test fixture was designed and fabricated which allowed full-scale 155mm non-rigid payload assemblies to undergo the combined spinning and simple coning motion of the projectile in flight. The resulting despin moment produced by the non-rigid payload was used to evaluate the potential flight stability of a projectile carrying the non-rigid payload. Test fixture evaluation of the partial solid/partial liquid payload indicates that the payload induced despin moment increases non-linearly with both coning frequency and coning angle. The despin moment is independent of canister spin rate providing a minimum spin rate of about 1,000 rpm is present. Below this spin rate, the despin moment is markedly decreased. Modifying the shaping and composition of the solid elements of the payload to restrict their movement reduced the despin moment and the associated flight instability potential. Fixture tests with homogeneous, viscuos liquid fills produced similar despin characteristics to those obtained with the partial solid/partial liquid payloads. The similarity in the instability characteristics due to both the simple homogeneous, viscous liquids and the more complex partial solid/partial liquid non-rigid payloads could aid in the development of a general theory describing the source of the instability and establishing design criteria for future projectile applications.

Descriptors :   *Smoke projectiles, *Spinning(Motion), *Stability, Projectile trajectories, Payload, Liquids, Solids, Canisters, Conical bodies, Rates, Test methods, Test and evaluation

Subject Categories : Pyrotechnics
      Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE