Flutter Analysis of an Uninhabited Aerial Vehicle
PI Claudia Moreno
The aerodynamic advantages of high aspect ratio flexible wings, such as improved performance and lower fuel consumption, are being exploited to develop autonomous aircraft for intelligence, surveillance and reconnaissance missions. These light-weight, high-altitude, long-endurance vehicles with large wing span exhibit high flexibility and significant deformation in flight leading to increased interaction between the aerodynamics and structural dynamics. This phenomenon, called flutter, occurs as the aircraft wing torsion mode decreases with airspeed and interacts with the wing bending mode. The interaction can lead to poor handling qualities and may result in dynamic instability. Hence, a detailed study of these dangerous interactions is required to guarantee the structural safety of the aircraft.
| Flutter modeling includes the interaction of the aircraft flexible structure, steady and unsteady aerodynamic forces resulting from the aircraft motion, and the flight control system. This project proposes the use of a modeling approach based on the rigid-body dynamics augmented with linear structural modeling. Here, the coupled nonlinear equations are simplified by the mean axes assumptions, resulting in independent equations for the rigid body dynamics and elastic deformations. These decoupled equations can be then linearized to obtain a linear, parameter-varying (LPV) system where the scheduling parameters are typically airspeed and altitude. |
Methodology:
1. Rigid body simulation. This includes identification of mass properties, modeling of aerodynamic forces, system identification and model updating from flight data. 2. Structural model. This consists of identification of the stiffness of the different components of the UAV. System identification from ground vibration tests. Finite element modeling. 3.Integration of structural model to the rigid body simulation. 4. Flutter analysis. Stability analysis of linear models at different velocities. 5. Design of controllers for vibration suppression. |  |
Research Dates
07/10/2016
Categories: Graduate