Aeroservoelastic analysis and robust controller synthesis for flutter suppression of air vehicle control actuation systems

Akmeşe, Alper
Flutter is one of the most important phenomena in which aerodynamic surfaces become unstable in certain flight conditions. Since the 1930’s many studies were conducted in the areas of flutter prediction in design stage, research of design methods for flutter prevention, derivation and confirmation of flutter flight envelopes via tests, and in similar subjects for aircraft wings. With the use of controllers in 1960’s, studies on the active flutter suppression began. First the classical controllers were used. Then, with the improvement of the controller synthesis methods, optimal controllers and later robust controllers started to be used. However, there are not many studies in the literature about fully movable control surfaces, commonly referred to as fins. Fins are used as missile control surfaces, and they can also be used as a horizontal stabilizer or as a canard in aircraft. In the scope of this thesis, controllers satisfying the performance and flutter suppression requirements of a fin are synthesized and compared. For this purpose, H2, Hinf, and mu controllers are used. A new flutter suppression method is proposed and used. In order to assess the performance of this method, results obtained are compared with the results of another flutter suppression method given in the literature. or the purpose of implementation of the controllers developed, aeroelastic model equations are derived by using the typical section wing model with thin airfoil assumption. The controller synthesis method is tested for aeroelastic models that are veloped for various flow regimes; namely, steady incompressible subsonic, unsteady incompressible subsonic, nsteady compressible subsonic, and unsteady compressible supersonic.


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Balevi, Taner Birtan; Kayran, Altan; Department of Aerospace Engineering (2012)
Flutter is a dynamic instability which can result in catastrophic failures of an air vehicle. Preventing flutter can be an important factor in the aircraft design, affecting the structural design. Thus, the weight and performance of the aircraft is also being affected. Understanding the role of each design factor of a wing on the onset of flutter can help designers on the flutter clearance of the aircraft. Analysis to predict flutter, ground vibration tests and flight flutter tests, which are performed to v...
Aeroservoelastic Modelling and Analysis of a Missile Control Surface with a Nonlinear Electromechanical Actuator
Mehmet Ozan, Nalcı; Kayran, Altan (null; 2014-06-16)
In this study, aeroservoelastic modeling and analysis of a missile control surface which is operated and controlled by a power limited, nonlinear electromechanical actuator is performed. Linear models of the control fin structure and aerodynamics together with the nonlinear servo-actuation system are built and integrated. The resulting aeroservoelastic system is analyzed both in time and frequency domain. Structural model of the control fin is based on the finite element model of the fin. Aerodynamic model ...
Numerical and experimantal analysis of flapping motion
Sarıgöl, Ebru; Alemdaroğlu, Hüseyin Nafiz; Department of Aerospace Engineering (2007)
The aerodynamics of two-dimensional and three-dimensional flapping motion in hover is analyzed in incompressible, laminar flow at low Reynolds number regime. The aim of this study is to understand the physics and the underlying mechanisms of the flapping motion using both numerical tools (Direct Numerical Simulation) and experimental tools (Particle Image Velocimetry PIV technique). Numerical analyses cover both two-dimensional and three-dimensional configurations for different parameters using two differen...
Flutter analysis of fixed and rotary wings
Çiçek, Orhun; Kayran, Altan; Department of Aerospace Engineering (2019)
Flutter is a critical stability problem that needs to be considered for the design of fixed and rotary wings. Although flutter susceptibility is addressed during the test phases of the most of the aircraft, an analytical model is required for the determination of flutter boundaries and most importantly for supplying feedback to the design procedure in order to have a structure that is free from flutter. In this thesis, several flutter analysis methodologies are investigated for both fixed and rotary wing st...
Aeroelastic Modelling and Testing of a Thin Laminated Composite Missile Fin/Wing
Aslan, Göktuğ; Kırımlıoğlu, Serdar; Kurtuluş, Dilek Funda (null; 2017-06-09)
Missile fins or wings exposed to different coupled aerodynamic loads during the mission or flight at subsonic and supersonic velocity profile. Aerodynamic loads varying with the angle of attack and the velocity profile may cause some structural fatigue and failure problems. In order to achieve such problems, high strength materials such as composites are required. In this work, a laminated composite missile fin was investigated in terms of the strength varying with the aerodynamic profile. The fiber orienta...
Citation Formats
A. Akmeşe, “Aeroservoelastic analysis and robust controller synthesis for flutter suppression of air vehicle control actuation systems,” Ph.D. - Doctoral Program, Middle East Technical University, 2006.