Evaluation of Aircraft Model Upset Behaviour Using Wind Tunnel Manoeuvre Rig

Abstract

This paper discusses the development of a novel multi-degree-of-freedom dynamic manoeuvre rig aimed at investigation of aircraft upset/LOC-related behaviour in the wind tunnel. The motivation behind the development and characteristics of the rig are first described, along with example behaviour of an aircraft model exhibiting nonlinear timedependent aerodynamics in an open-jet low-speed wind tunnel. Test objectives for assessment of upset onset scenarios -both for parameter estimation purposes and to 'physically simulate' the behaviour -are then described, as is the design of the upgraded instrumentation system to facilitate experimental investigastion. Finally, examples of relevant behaviour involving real-time control of the rig to explore nonlinear conditions leading to upset are presented; these are evaluated in terms of prospects for such testing in aircraft development and analysis projects.

Numerical Investigations of Subscale Flexible High Aspect Ratio Aircraft on a Dynamic Wind Tunnel Rig

“…The rear of the rig has an aerodynamic compensator, which can be used to create forced rig motions or attempt to compensate rig effects on the aircraft model response. The manoeuvre rig has previously been used to study nonlinear and time-dependent aerodynamic effects such as LCOs and hysteresis in rigid body aircraft pitch, as well as for the development of mathematical models via parameter estimation and aerodynamic characterization of model aircraft [17][18][19][20][21].…”

Capturing nonlinear time-dependent aircraft dynamics using a wind tunnel manoeuvre rig

“…the compensation of roll motion using the aerodynamic compensator (Figure 1a) [3], investigating aerodynamic hysteresis utilising a feedback control law to track the aircraft's equilibria [15] and studying the effects of geometric constraints on the coupled rig/aircraft dynamics by feedback of load cell reaction force measurements to the compensator control surfaces [27].…”

“…More recently, experimental exploration of the LCO behaviour using an updated version of the manoeuvre rig was carried out [3]. These experiments were conducted to further explore the lateral-directional interaction between the different degrees of freedom as nonlinear phenomena appear (first observed by Pattinson et al [31], despite the absence of direct measurements of the model aileron δ m ail , elevator δ m ele and rudder δ m rdd or rotation rates p m , q m , r m ) and to explore roll motion compensation using the aerodynamic compensator control surfaces.…”

Wind Tunnel Manoeuvre Rig: A Multi-DOF Test Platform for Model Aircraft

“…6 The principal enhancements are new instrumentation, an improved data acquisition and command electronics system, a new real-time data acquisition software system based on Python, the interfacing with Matlab Simulink and the replacement of the 2-DOF gimbal at the interface between the model and the front of the rig arm with a newly-designed 3-DOF gimbal, which requires the development of a new mathematical model. Additional modifications to the rig included a new IMU module, changes to the arm-roll measurement system, together with improvements to the compensator servos.…”