Wind-tunnel tests of an 81 mm mortar projectile augmented with a single pair of relatively high-aspect-ratio canards have verified that such an airframe is statically unstable in the canard plane with significant nonlinear aerodynamic characteristics with respect to angle of attack. It is shown here that an open-loop control scheme may be used effectively under a free-rolling arrangement, provided that the noncanard plane contains sufficient static stability and that the “roll-averaged” aerodynamic considerations are addressed adequately. These considerations include establishing a condition for the level of static stability required in a roll-averaged sense and ensuring that an adequate roll rate is present during maneuvers. Six-degree-of-freedom simulation results based on a wind-tunnel derived aerodynamic model that accounts for the nonlinear angle of attack dependencies, along with postflight analysis from a controlled flight experiment, have aided in the verification of the open-loop control concept for a rolling airframe that contains an unstable pitch plane.
Aerodynamic Considerations for Open-Loop Control of a Statically Unstable Mortar Projectile
Journal of Spacecraft and Rockets ; 51 , 5 ; 1576-1586
2014-09-01
Article (Journal)
Electronic Resource
English
High L/D projectile aerodynamic considerations
AIAA | 1996
|Approach to control of statically unstable manned flight vehicles
Engineering Index Backfile | 1961
|Statically unstable flying wing layout aircraft stability augmentation control method
European Patent Office | 2020
|Stabilization of statically unstable systems by parametric excitation
Online Contents | 2009
|