Accession Number : ADP001030

Title :   A New Flight Instability Affecting Spinning Projectiles Having Non-Rigid Payloads,

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

Personal Author(s) : Miller,Miles C.

Report Date : FEB 1983

Pagination or Media Count : 12

Abstract : Severe flight instabilities were experienced by an Army spin stabilized projectile which had a partial solid/partial liquid payload. Characteristic of this flight instability was a sharp increase in projectile yaw angle accompanied by an abrupt loss in projectile spin rate. Although it was known that this instability was due to movement on the non-rigid payload, the exact mechanism causing the effect was not understood. A special laboratory test fixture was used to force a full-scale projectile payload to simulate the combined spin and simple coning motion of the projectile in flight. The fixture was used to determine critical factors influencing the payload induced despin moment, and from this the associated flight stability was inferred. Candidate payload configurations intended to eliminate the instability were evaluated on the fixture culminating in a payload design which provided the desired functional and flight performance. Subsequent fixture tests with homogeneous, viscous liquid fills produced similar despin characteristics to those obtained with the partial solid/partial liquid payloads.

Descriptors :   *Flight simulation, *Liquid filled projectiles, *Aerodynamic stability, *Payload, Test fixtures, Spinning(Motion), Army research, Canisters, Configurations, Smoke screens, Yaw, Angles, Liquids, Viscosity, Experimental data

Distribution Statement : APPROVED FOR PUBLIC RELEASE