Article
Engineering, Mechanical
Sai Vishal, Ashwad Raaj, Chandan Bose, J. Venkatramani, Grigorios Dimitriadis
Summary: The present study investigates the bifurcation characteristics of a pitch-plunge aeroelastic system with coupled non-smooth nonlinearities in both structural and aerodynamic aspects. The study shows that the freeplay gap plays a key role in combining the effects of structural and aerodynamic nonlinearities. Interesting discontinuity-induced bifurcation scenarios arise at high values of the freeplay gap, which can significantly impact the safety of the aeroelastic system.
NONLINEAR DYNAMICS
(2022)
Article
Engineering, Electrical & Electronic
Aykut Tamer
Summary: The study explores the response of aircraft wings to external store separation, presenting the use of flexible multibody dynamics for simulation and demonstrating its features and benefits.
Article
Engineering, Aerospace
Marta Colella, Francesco Saltari, Marco Pizzoli, Franco Mastroddi
Summary: This paper introduces the sloshing effects on aeroelastic stability and response of flying wing configurations. A reduced order model based on computational fluid dynamics data is used to account for both rigid and elastic behavior of flexible aircraft. The study compares stability and response analyses with a frozen fluid case to demonstrate the impact of fluid movement on overall aircraft behavior.
AEROSPACE SCIENCE AND TECHNOLOGY
(2021)
Article
Mechanics
Omar Yousef Al-Thehabey
Summary: This research developed computational algorithms to address aeroelastic effects on aircraft wings, achieving good match with lab observations but showing discrepancies under severe external conditions. Validation was performed with multiple methods, and close results were obtained in terms of pressure coefficients, dynamics, and instability calculations.
Article
Engineering, Aerospace
Mohammadreza Amoozgar, Michael Friswell, Seyed Ahmad Fazelzadeh, Hamed Haddad Khodaparast, Abbas Mazidi, Jonathan E. Cooper
Summary: This paper investigates the aeroelastic stability of an electric aircraft wing with distributed electric propulsion. The study shows that the tip propulsor's thrust, mass, and angular momentum have the most significant impact on the wing's stability.
Review
Engineering, Aerospace
Jeet Panchal, Haym Benaroya
Summary: In recent decades, there has been growing interest in the field of nonlinear aeroelasticity, particularly in revisiting the control surface freeplay problem with improved computing capabilities. Modern theoretical and experimental analyses have led to various modeling approaches, but differing numerical predictions persist in the study of aeroelastic dynamical behavior and properties related to freeplay.
PROGRESS IN AEROSPACE SCIENCES
(2021)
Article
Engineering, Mechanical
Y. M. Chen, W. L. Li, B. F. Yan, J. K. Liu
Summary: Freeplay in the aeroelastic system of an airfoil with a control surface can significantly influence aeroelastic behavior, reducing the flow velocity at which a limit cycle may arise. A method based on eigenvalue analysis of a generalized Jacobian matrix has been proposed to easily calculate the lowest velocity and detect multiple subcritical LCs. The method can also determine the occurrence of subcritical LCs and distinguish between subcritical and supercritical LCs using the distribution of positive real parts.
NONLINEAR DYNAMICS
(2021)
Article
Acoustics
Ali Esmaeili, Hugo Emanuel da Costa Delgado, Joao Manuel Melo Sousa
Summary: This study explores the possibility of scavenging energy from aeroelastic vibrations to improve the aerodynamic performance of fixed-wing micro aerial vehicles. The passive component of the system generates intense vortices, resulting in vortex-induced vibrations. By installing a piezoelectric energy harvesting device and tuning it for resonant response, the extracted power from structural vibrations can be used to power the active component of the stall control system.
JOURNAL OF VIBRATION AND CONTROL
(2023)
Article
Computer Science, Information Systems
Jovani Ortega Ventura, Daniel Benitez Morales, Jesus P. Ordaz Oliver, Eduardo S. Espinoza Quesada
Summary: This paper presents the design of a robust controller to stabilize the mechanical dynamics of an Unmanned Aerial Vehicle by considering the actuator bandwidth. It attenuates both matched and unmatched uncertain dynamics as well as external disturbances. The performance of a sliding mode controller is improved by combining it with the attractive ellipsoid method. It is ensured that the system trajectory reaches a minimal size invariant set in finite time. Numerical simulations using a multirotor aircraft validate the effectiveness of the proposed controllers.
Article
Engineering, Aerospace
Chang-ho Ji, Chong-sup Kim, Byoung-Soo Kim
Summary: This paper proposes a hybrid control method to minimize transient response during store launch and reduce unexpected roll motion during longitudinal flight maneuvers in highly maneuverable fighter aircrafts, effectively improving flying qualities and mission efficiency.
Article
Mechanics
J. -J. Sinou
Summary: This paper investigates the stability of a two-dimensional controlled airfoil system with time delay and proposes a hybrid approach to predict the critical time delay and flutter instability angular frequency. The study reveals that time delay can affect the effectiveness of control design, and discusses the effectiveness and drawbacks of two proposed controllers through numerical simulations.
EUROPEAN JOURNAL OF MECHANICS A-SOLIDS
(2022)
Article
Engineering, Aerospace
Lennart Lobitz, Hendrik Traub, Mats Overbeck, Maximilian Bien, Sebastian Heimbs, Christian Huehne, Jens Friedrichs, Peter Horst
Summary: This study examines the impact of different suction panel configurations on wing mass and load transfer for an all-electric short-range aircraft. The results show that suction panels made from Ti6Al4V offer the most robust design and significantly increase wing mass, while panels made from Nylon11CF or PU1000 do not significantly increase wing mass. However, the use of these materials raises questions about their robustness under operational conditions.
Article
Engineering, Mechanical
N. Menga, F. Bottiglione, G. Carbone
Summary: We studied the dynamic behavior of a lattice of bristle-like elastic elements at the interface between a rigid still substrate and a rigid sliding slab. Complex bristles dynamics occur due to interactions with the moving slab, potentially altering the overall frictional response. Three main mechanisms of friction control were identified: modulation of local friction force based on relative velocity; misalignment between local relative velocity and slab velocity due to transverse vibration; and local friction coefficient variation due to normal load on the bristle. Results show that a significant reduction in friction force opposing slab motion can be achieved, depending on interface properties and involving self-excited bristle vibration. This research suggests possible mechanisms of friction control in different practical applications.
NONLINEAR DYNAMICS
(2023)
Article
Automation & Control Systems
Liam Vile, Halim Alwi, Christopher Edwards
Summary: This paper introduces a novel control allocation method designed for fault tolerant control of over-actuated systems, which allows some actuators to remain inactive under nominal fault-free conditions. An adaption process is used to compensate for inactive actuators when active actuators fail, and a gradient descent algorithm is proposed for this adaptation to prevent actuator saturation and maintain system performance. The paper also presents rigorous conditions for sliding to occur in a finite time and ensure stable motion, demonstrating the effectiveness of the control scheme on a high-fidelity blended wing body aircraft model.
IET CONTROL THEORY AND APPLICATIONS
(2021)
Article
Engineering, Mechanical
Mengshi Song, Panfeng Huang
Summary: This paper accurately establishes a system model of the tethered aircraft system composed of a multi-link tether model and the 6-degree-of-freedom dynamics of the aircraft by introducing the elasticity and length variation of the tether. An extended state observer-based adaptive dynamic surface control approach is proposed to solve the difficulty of anti-disturbance control in the system.
NONLINEAR DYNAMICS
(2022)
