Aerodynamic Characterizations of Asymmetric and Maneuvering 105-, 120-, and 155-mm Fin-Stabilization Projectiles Derived from Telemetry Experiments

摘要

Accurate knowledge of candidate projectiles aerodynamics is crucial for successful development of tube- and gun-launched precision munitions. This is especially true when control authority is low, as is often the case with rolling projectiles. In these instances, truth models of the projectiles flight characteristics need to be of sufficient quality to enable the guidance, navigation, and control (GNC) system to produce efficient corrective maneuvers. Recently, the U.S. Army conducted instrumented flight experiments to quantify aerodynamics and flight dynamics for three U.S. Army precision munitions programs. These projectiles were of different shapes and calibers (105, 120, and 155 mm), but similar in having supercaliber, roll-inducing tailfins and employing nose-mounted canards as their maneuver control mechanisms. In this effort, for the first time, aerodynamic terms for precision airframes and control mechanisms were estimated from data acquired from projectile onboard instrumentation via elevated gun firings. Observations of these complexities were possible because data were collected for the entire free flights of these projectiles encompassing varying Mach numbers and dynamic conditions not previously examined, thereby complementing the pre-flight analyses and reducing cost by enabling characterization of more aerodynamic parameters with less testing.