Linearized Rigid-Body Static and Dynamic Stability of an Aircraft with a Bio-Inspired Rotating Empennage

Abstract

This work explores the effects of a Bio-Inspired Rotating Empennage (BIRE) on the static and dynamic stability and handling qualities of a fighter aircraft. The BIRE-modified aircraft does not have a vertical tail, and is instead capable of rotating the horizontal tail about the body x-axis for maneuvering. The dynamic characteristics of the BIRE-modified aircraft are compared to a baseline unmodified aircraft, similar to the F16, with a traditional vertical tail in the linear aerodynamic range below stall. Linearized aerodynamic models for each aircraft, based on previous work, are used alongside a set of coupled dynamic equations of motion for asymmetric aircraft, derived in this work, to estimate the dynamic response of each aircraft to disturbances from steady level and banked trim conditions. The static stability analysis suggests that modifying the baseline with a BIRE decreases the aircraft’s static pitch, roll and yaw stability. The dynamic stability analysis suggests that modifying the baseline aircraft with a BIRE; 1) slightly decreases the aircraft’s short period damping and slightly increases the aircraft’s short period frequency, 2) decreases the aircraft’s phugoid damping and slightly increases the aircraft’s phugoid frequency, 3) slightly increases the aircraft’s roll damping, 4) decreases the aircraft’s spiral damping for steady level flight and increases the aircraft’s spiral damping sensitivity to center of gravity location when banked, and 5) produces a non-traditional dutch roll mode. The handling quality analysis suggests that modifying the baseline aircraft with a BIRE has a negligible effect on the aircraft’s short period, phugoid, roll, and spiral handling quality levels, but decreases the aircraft’s dutch roll handling quality levels.