Aeroelasticity Research Papers - Academia.edu (original) (raw)

Top Papers
Most Cited Papers
Most Downloaded Papers
Newest Papers
People
- by
- •
- Engineering, Viscoelasticity, Vibration, Aeroelasticity

This paper is focused on numerical investigations that analyze the advantages obtained from high-aspect-ratio wings with unconventional roll control strategies based on wing twist morphing. The sailplane G103-B, produced by the GROB Werke company, was chosen as the reference aircraft for the analyses. For confidentiality reasons, the data disclosed by the builder covered only general properties such as the main dimensions, the lifting surface airfoils and attitudes, the characteristic speeds, and a rough mass budget. As a consequence of this, "reverse-engineering" was considered necessary to define a reasonable wing structural layout that enabled the analysis of the elastic-aircraft roll dynamics.Apreliminary sizing of the wing structure was addressed using CS-22 airworthiness requirements and by adopting fast elementary approaches. The estimated structural arrangement, which was verified using a finite element analysis, was then used to generate the aircraft aeroelastic model. The conventional (aileron-based) and the unconventional (wing twist morphing) roll control strategies were compared from the aerodynamic and the aeroelastic standpoints, and the benefits achieved with the unconventional strategy are summarized.

- by Rosario Pecora
- •
- Aerospace Engineering, Aeronautical Engineering, Aerodynamics, Aircraft Design

This work describes advanced numerical aero-hydro-servo-elastic simulations of a floating offshore wind turbine using a multi-body vortex-particle based solver. The floating offshore substructure considered in this study is the spar-buoy as described in Phase IV of the Offshore Code Comparison Collaboration (OC3) project [1]. The wind turbine blades and rotor-wake aerodynamics are modeled using the lifting-line theory and particle-mesh approaches, respectively. The wind turbine structure and foundation are modeled using a finite-element and muti-body system approach. Last, hydrodynamics are modeled using
Airy wave theory. To calculate the forces acting on the structure, Morison’s equation is used for the floating spar-buoy. The developed aero-hydro-servo-elastic tool represents a more advanced approach to traditional tools used in industry based on blade-element momentum (BEM) for simulating floating offshore wind turbine performance.

- by Matias Sessarego
- •
- Hydrodynamics (Physics), Aerodynamics, Aeroelasticity, Wind turbine
- by Efraín Alcorta García
- •
- Aerospace Engineering, Aerodynamics, Aeroelasticity, Air traffic control
- by Joaquim R R A Martins
- •
- Engineering, Aerodynamics, Finite element method, Topology
- by Seyed M. Hashemi
- •
- Engineering, Finite element method, Aeroelasticity, Flutter

SKYCAR is a CS-23 category aircraft designed and produced by OMA SUD to be the actual sole multi-utility/multipurpose aircraft in the General Aviation High Performance Piston marketplace with an opening bonnet on fly. The out-of-standards configuration -characterized by a double vertical tail surmounted by a fully movable horizontal tail and connected to the fuselage by means of two large boomsrepresented the key-reason of a quite challenging proof of compliance to EASA requirements in terms of flutter instability. Due to the inapplicability of consolidated simplified criteria, rational analyses supported by test evidence were considered mandatory, thus demanding for a wide set of numerical and experimental activities to be performed. In this paper a general overview of such activities has been presented by pointing out the used approaches, analysis methods as well as the numerical tools implemented on their base.

- by Rosario Pecora
- •
- Aerospace Engineering, Aeronautical Engineering, Modal Analysis, Aircraft Design
- by Rana Lekh
- •
- Aeroelasticity, Flutter, Theodorsen, Wind Section Analysis
- by Peter Horst
- •
- Engineering, Fluid structure interaction, Aeroelasticity, Fluids
- by Jawad Khawar
- •
- Fluid structure interaction, Aeroelasticity, ANSYS FLUENT, Grid Deformation
- by max platzer
- •
- Methodology, Theory, Aerodynamics, Vibration
- by xiaochen wang
- •
- Aeroelasticity, Titanium alloys, Thermal Power Plants

The wing of aircraft is designed according to the mission or operational purposes. In the design, maintenance and operations of training aircrafts, cost, reliability and safety are some of the most important parameters to consider. Wing performances are not just determined by their aerodynamic characteristics but also their structural characteristics which is the ability to sustain both internal and external loads. In addition to the internal weights of the spars, ribs, stringers, landing gear and tanks, the fuel load and aerodynamic loads are external forces that act on the structure and exert pressure on it. This paper will concentrate on the structural design of the wing of a two-seater trainer aircraft. The report addresses both modeling and simulation in order to evaluate the wing structural performances. The modeling is performed using SolidWorks and the simulation using ANSYS. Also, a MATLAB m-file coding is used to generate the wing external dimensions. The result of the simulation is then analyzed and interpreted. At the end, a construction of V-n diagram for the designed wing is achieved.

- by Rossana Jaca
- •
- Mechanical Engineering, Civil Engineering, Aerospace Engineering, Modeling

A study on the divergence phenomena of airfoils , and improvements.

- by Zeinab El-Sayegh
- •
- Vibrations, Aerodynamics, Aeroelasticity, Aeroelastic Flutter

The integration of advanced distributed propulsion (DP) systems within various aircraft configurations holds the potential to greatly increase aircraft performance, particularly in terms of fuel efficiency, reduction of harmful emissions and reduction of take-off field length requirements. This has been enabled by modern analysis tools, materials technology and control systems which take advantage of the positive interactions between the propulsive configuration and the aerodynamics of the aircraft. In particular, synergies are maximized when the propulsion system uses distributed nozzles, crossflow fans and multiple distributed fans. Recent advances in electric propulsion have encouraged the hybridization of propulsive systems, with airliners having multiple electric fans powered by one or two gas turbine engines. Furthermore, due to recent advances in airframe integration solutions, the propulsive element can become an integral part of the control and stability augmentation capabilities of the aircraft. Thereby, the digital control of advanced DP systems is crucial for the purpose of thrust modulation and intelligent management of engine resources and health. This not only aids in mission optimization but also support the case for airworthiness certification of novel aircraft configurations integrating advanced DP systems. This paper presents a critical review of the existing literature on the subject of DP, identifying the benefits and drawbacks of this technology as well as its proposed practical applications. The review also discusses contemporary advances in hybrid electric technology, aeroelasticity research and the fundamental design steps to integrate advanced DP systems in fixed-wing aircraft. Additionally, an evolutionary outlook is presented on digital control of DP systems with a focus on advancing the techniques for mission optimization and engine health management for enhanced safety and sustainability. Based on the proposed design principles and digital control methodology, conclusions are drawn about the suitability of advanced DP for various applications and recommendations are made for future research and development.

- by Bogdan Neculăescu
- •
- Aeroelasticity, Aeroelastic Flutter
- by Rakesh Kapania
- •
- Engineering, Artificial Intelligence, Genetic Algorithms, Finite element method
- by Michael Hounjet and +1
- •
- Aeroelasticity
- by Rafael Palacios
- •
- Mechanical Engineering, Aerospace Engineering, Aeroelasticity

Aerodynamic and structural dynamic performance analysis of modern wind turbines are routinely carried out in the wind energy field using computational tools known as aero-elastic codes. Most aero-elastic codes use the blade element momentum (BEM) technique to model the rotor aerodynamics and a modal, multi-body, or finite-element approach to model the turbine structural dynamics. A novel aeroelastic code has been developed called MIRAS-FLEX. MIRAS-FLEX is an improvement on standard aero-elastic codes because it uses a more advanced aerodynamic model than BEM. MIRAS-FLEX combines the three-dimensional viscous-inviscid interactive method, MIRAS, with the dynamics model used in the aero-elastic code FLEX5. Following the development of MIRAS-FLEX, a surrogate optimization methodology using MIRAS alone has been developed for the aerodynamic design of wind-turbine rotors. Designing a rotor using a computationally expensive MIRAS instead of an inexpensive BEM code represents a challenge, which is resolved by using the proposed surrogate-based approach. The approach is unique because most aerodynamic wind-turbine rotor design codes use the more common and inexpensive BEM technique. As a verification case, the methodology is applied to design a model wind-turbine rotor and is compared in detail with the one designed with BEM. Results demonstrate the methodology is effective for the aerodynamic design of wind-turbine rotors. To perform more realistic large wind-turbine rotor designs, a structural design code was needed. Such a structural design code has been developed to minimize the cost of energy (COE) of the NREL 5MW wind-turbine blade. Blade stiffness and mass are computed using the NREL PreComp code based on the classical laminate theory, while blade natural frequencies are obtained from the NREL BModes code. The aero-elastic program FLEX5 computes loads based on design load cases from the IEC standards, which are then used to compute the deflections, strains, and buckling constraints. The minimum COE is found by implementing the procedure with a gradient-based optimizer and using the wind turbine design cost and scaling model of NREL. Last, a unique framework to design large wind-turbine rotors has been developed by combining MIRAS-FLEX, the surrogateoptimization code, and the structural design code. The optimization framework was used to design large wind turbine blades using both FLEX5 and MIRAS-FLEX with good results obtained.

- by Matias Sessarego
- •
- Aerodynamics, Aeroelasticity, Wind turbine
- by Daniel Schrage and +1
- •
- Aeronautical Engineering, Composite Materials, Aeroelasticity
- by P. Piperni
- •
- Engineering, Modeling, Engineering Design, Aerodynamics

Morphing Wings Technologies: Large Commercial Aircraft and Civil Helicopters offers a fresh look at current research on morphing aircraft, including industry design, real manufactured prototypes and certification. This is an invaluable reference for students in the aeronautics and aerospace fields who need an introduction to the morphing discipline, as well as senior professionals seeking exposure to morphing potentialities. Practical applications of morphing devices are presented-from the challenge of conceptual design incorporating both structural and aerodynamic studies, to the most promising and potentially flyable solutions aimed at improving the performance of commercial aircraft and UAVs. Morphing aircraft are multi-role aircraft that change their external shape substantially to adapt to a changing mission environment during flight. The book consists of eight sections as well as an appendix which contains both updates on main systems evolution (skin, structure, actuator, sensor, and control systems) and a survey on the most significant achievements of integrated systems for large commercial aircraft. Provides current worldwide status of morphing technologies, the industrial development expectations, and what is already available in terms of flying systems Offers new perspectives on wing structure design and a new approach to general structural design Discusses hot topics such as multifunctional materials and auxetic materials Presents practical applications of morphing devices. © 2018 Elsevier Ltd. All rights reserved.

In this study, the aeroelastic stability and response of an aircraft swept composite wing
in subsonic compressible flow are investigated. The composite wing was modeled as an
anisotropic thin-walled composite beam with the circumferentially asymmetric stiffness
structural configuration to establish proper coupling between bending and torsion. Also,
the structural model consists of a number of nonclassical effects, such as transverse
shear, material anisotropy, warping inhibition, nonuniform torsional model, and rotary
inertia. The finite state form of the unsteady aerodynamic loads have been modeled based
on the indicial aerodynamic theory and strip theory in the subsonic compressible flow.
Novel Mach dependent exponential approximations of the indicial aerodynamic functions
have been developed. The extended Galerkin’s method was used to construct the mass,
stiffness, and damping matrices of the nonconservative aeroelastic system. Eigen analysis
of the system was performed to obtain the aeroelastic instability (divergence and flutter)
boundaries. Also, solving the equations of motion in the time domain leads to the aeroelastic
response of wing in different flight speeds. The obtained results are compared with
the available results in the literature, which reveals an excellent agreement. The numerical
results obtained in this article seek to clarify the effects of geometrical and material
couplings and flight Mach number on the aeroelastic instability and response of composite
wings in subsonic compressible flow

- by touraj farsadi
- •
- Structural Dynamics, Aeroelasticity, Aeroelastic Flutter
- by Josef Trchalik
- •
- Aerospace Engineering, Stability, Aeroelasticity, Rotorcraft
- by Dewey Hodges
- •
- Aerodynamics, Structural Analysis, Aeroelasticity, Finite Element Analysis
- by Gle Dys
- •
- HELICOPTER DESIGN, Aeroelasticity

This presentation introduces the design optimization of ANSYS Workbench analysis using VisualDOC. VisualDOC is a powerful tool for multidisciplinary design process integration, execution and automation. It offers a friendly interface that allows the users to easily define the components and create the work flow for design optimization. ANSYS Workbench is an innovative project platform that guides the users through complex multiphysics analyses via ‘drag-and-drop’ tactic. The project-level parameter management and update mechanism enables external execution of ANSYS without interfering the sub-system level analyses. This presentation demonstrates the implementation of multidisciplinary design optimization for ANSYS analysis using VisualDOC as optimizer. The coupling between VisualDOC and ANSYS is accomplished in an automated manner such that no programming effort is required. A design optimization of a mixing elbow, a multi-objective optimization of an aero-elastic wing, and a response-surface-based optimization for a flapping plate are used to illustrate the proposed functionality.

- by Ahsan Kareem
- •
- Engineering, Aerodynamics, Aeroelasticity, Bridge
- by Michael Hounjet
- •
- Aeroelasticity
- by Matteo Diez
- •
- Engineering, Aeronautical Engineering, Optimization techniques, Aircraft Design

Acoustics is the science concerning the study of sound. The effects of
sound on structures attract overwhelm interests and numerous studies were carried out in
this particular area. Many of the preliminary investigations show that acoustic pressure
produces significant influences on structures such as thin plate, membrane and also highimpedance
medium like water (and other similar fluids). Thus, it is useful to investigate
structural response to acoustics on aircraft, especially on aircraft wings, tails and control
surfaces which are vulnerable to flutter phenomena. The present paper describes the
modelling of structure-acoustic interaction to simulate the external acoustic effect on
binary flutter model. Here, the model is illustrated as a rectangular wing where the
aerodynamic wing model is constructed using strip theory with simplified unsteady
aerodynamics involving the terms for flap and pitch degree of freedom. The external
acoustic excitation, on the other hand, is modelled using a four-node quadrilateral
isoparametric element via finite element approach. Both equations are then carefully
coupled and solved using eigenvalue solution. Next the mentioned approach is
implemented in MATLAB and the outcome of the simulated results are later described,
analyzed and illustrated.

- by Harijono Djojodihardjo and +1
- •
- Aerospace Engineering, Computational Fluid Dynamics, Aeronautical Engineering, Structural Dynamics

"The paper presents the maturation of a full potential flow solver whose primitive form [1] was
developed in the Brite-Euram project HELISHAPE, and aiming at a robust and fast aerodynamic
system, ready for industrial applications.
In particular the modelling of blade boundary layers, the modelling of the vortex wake system, the
inviscid potential flow solver methodology and the grid generator are described.
The resulting system is able to carry out the viscous non-linear aerodynamic analysis of rotorcraft
blade configurations in realistic hover and forward flight conditions.
Calculated results are presented for 2D airfoils, 3D wings and isolated rotors."

- by Michael Hounjet
- •
- System Identification, Aeroelasticity, Reduced order modeling, Controls
- by Luciano Demasi
- •
- Engineering, Modeling, Aerodynamics, Finite element method

This document describes the investigation of the behavior of the flow over a pitching NACA 0012 airfoil at Reynolds number Re=100,000 and Re=2,500,000 of the analysis of a two-dimensional k-ω SST (Shear Stress Transport) simulation. The behavior of the flow wake at the trailing edge is studied by the analysis of streamlines for each incidence angle and results are compared by the study of theoretical concepts and experimental data. The use of standard Unsteady Reynolds-Averaged Navier-Stokes (URANS) simulation has shown accuracy in predicting stall and reattachment incidence angles for upstroke and downstroke. The simulations were also capable of capturing flow information in agreement with experiments despite the over prediction of lift and drag coefficients, due to the two-dimensional simplification. The study has also compared the two-dimensional URANS k-ω SST turbulence model simulation data with previous results from three-dimensional simulation Wall Resolved Large Eddy Simulation (LES) and two-dimensional URANS k-ε Chien turbulence model analysis, showing that the qualitative behavior of the hysteresis loop is close for the computations, although there is a quantitative deviation in the results for upstroke and downstroke in the lift coefficient.

- by Alexandre Medina
- •
- Aeronautical Engineering, Aeroelasticity, CFD Analysis, Unsteady Aerodynamics

Modern wind turbine aero-structural blade design codes generally use a smaller fraction of the full design load base (DLB) or neglect turbulent inflow as defined by the International Electrotechnical Commission standards. The current article describes an automated blade design optimization method based on surrogate modeling that includes a very large number of design load cases (DLCs) including turbulence. In the present work, 325 DLCs representative of the full DLB are selected based on the message-passing-interface (MPI) limitations in Matlab. Other methods are currently being investigated, e.g. a Python MPI implementation, to overcome the limitations in Matlab MPI and ultimately achieve a full DLB optimization framework. The reduced DLB and the annual energy production are computed using the state-of-the-art aero-servo-elastic tool HAWC2. Furthermore, some of the interior dimensions of the blade structure are optimized using the finite-element based cross-sectional analysis tool BECAS. The optimization framework is applied to redesign the NREL 5 MW wind turbine blade to obtain improvements in rotor performance and blade weight.

- by Matias Sessarego
- •
- Structural Engineering, Structural Dynamics, Aeroelasticity, Wind turbine

"The aero-elastic simulation tool AESIM-BASIC18 has been applied in EADS Deutschland GmbH Military Aircraft in the past years for aero-elastic simulations on a modern fighter. The main intention of the application was to validate the tool for industrial aero-elastic applications, i.e. for steady aero-elastic calculations, deformation simulation, aerodynamic data set elastification purposes, for the generation of unsteady aerodynamic forces due to oscillating control surfaces, for the generation of generalised aerodynamic forces for flutter and gust analysis at subsonic, transonic and supersonic Mach numbers and finally for the simulation of flutter.
Results of the validation exercises are presented and discussed. In detail the validation with respect to steady aerodynamic simulations of a rigid wing alone and a complete rigid aircraft, as well as the validation of steady aerodynamic and steady aero-elastic simulations for the deformation of a flexible wing alone and a complete flexible aircraft have been carried out. The aero-elastic simulation of complete flexible aircraft has been validated. Validations of unsteady aerodynamic simulations of wings with oscillating control surfaces and with simulations of normal modes have been performed. Flutter and gust simulations have been validated using results from classical tools.
In all the applications the full potential model has been used only, although AESIM-BASIC has also other more, as well as less advanced possibilities for simulations.
The paper will focus on the demonstration of the industrial application of the NLR AESIM-BASIC tool through a critical overview of the detailed studies performed.
"

- by Michael Hounjet
- •
- System Identification, Aeroelasticity, Reduced order modeling, Controls

"This article presents strategies and models to efciently perform aero-elastic analysis according to
most recent experiences with aero-elastic tools and discusses applications of the multiple input
multiple output based (MIMOCLASS) identication which allows instantaneous ph utter analysis
during coupled simulations.
Details of models which are suitable candidates for improving efciency of aero-elastic methodologies
are presented. Especially attention is given to: i) the MIMO CLASS models; ii) improved
warping models (hybrid and trilinear volume spline, implicit lters, fuzzy splines et cetera );
iii) a novel concept (reduced order method) for grid deformation and iv) MIMO CLASS spectral
analysis."

- by Michael Hounjet
- •
- System Identification, Aeroelasticity, Reduced order modeling, Controls

With the progress of aircraft technology, materials and lighter aircraft structures, modern aircrafts are de-signed to be lighter and much more flexible. For the aircraft designers, manufacturers, as well as operators, the state of the art and trends of the structural dynamic characteristics of modern aircraft structures are of great interest and relevance. For instructional and conceptual study purposes, it would be of advantage to look into a simple method that may give instructive results. It is with such objectives that the present study is carried out. Various modern transport aircrafts are classified and investigated in view of their structural dynamic and aeroelastic characteristics of their wing structure. For this purpose, the basic philosophy and formulation of flutter phenomena as reflected in the generic binary flutter problem is revisited and reflected to real aircraft for general understanding and conceptual design purposes. To this end, a parametric study is carried out on the influence of geometrical and elastic properties of the wing structure on their structural dynamic and aeroelastic characteristics, in view of their performance and aeroelastic stability design requirements.

- by Harijono Djojodihardjo
- •
- Aerospace Engineering, Structural Dynamics, Aerodynamics, Aeroelasticity
- by Dewey Hodges
- •
- Engineering, Modeling, Vibration, Aeroelasticity
- by Mohammad Tawfik
- •
- Engineering, Modeling, Aerodynamics, Finite element method
- by Wei-xi Huang
- •
- Engineering, Fluid Mechanics, Modeling, Aeroelasticity

"The paper discusses and demonstrates novel
planar and non-planar interpolation techniques which
have been put forward by Hounjet. They are
based on the extension of the surface spline method
and on the application of integral equation methods
for the Laplace equation. The most promising one
is the so-called volume spline technique which is a
very simple method not requiring any additional logic
and which can be applied straightforwardly to any 3-D
data set, without drifting to far away from the origi-
nal data, even when the original data is non-smooth."

The response of an aircraft in flight to atmospheric gusts is one of the dynamic response problems, which
controls the wing design and dimensioning of large aircraft. In the present work, dynamic analysis of an aircraft
subjected to a one-dimensional random gust is carried out. Power spectral density (PSD) of gust is represented by both
von Karman and Dryden mathematical gust model. Finite element model (FEM) of a typical aircraft is generated
using Finite Element software. Aero dynamic modelling is also carried out. The Doublet-Lattice method (DLM) is
used for interfering lifting surfaces in subsonic flow. The analysis was performed using the advanced FEM software.
Natural frequencies are computed and mode shapes are identified. Continuous gust is applied on the aircraft and the
dynamic acceleration and bending moments are computed at critical locations. This work provides dynamic loads due
to gust using von Karman and Dryden models.