Download or read book Geometrical and Structural Properties of an Aeroelastic Research Wing Arw 2 written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-03 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt: Transonic steady and unsteady pressure tests were conducted on a large elastic wing known as the DAST ARW-2 wing. The wing has a supercritical airfoil, an aspect ratio of 10.3, a leading edge sweepback angle of 28.8 deg and is equipped with two inboard and one outboard trailing edge control surfaces. The geometrical and structural characteristics are presented of this elastic wing, using a combination of measured and calculated data, to permit future analyst to compare the experimental surface pressure data with theoretical predictions. Sandford, Maynard C. and Seidel, David A. and Eckstrom, Clinton V. and Spain, Charles V. Langley Research Center RTOP 505-63-21-02...

Download or read book Geometrical and Structural Properties of an Aeroelastic Research Wing ARW 2 written by and published by . This book was released on 1989 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Geometrical and Structural Properties of an Aeroelastic Research Wing ARW 2 written by Maynard C. Sandford and published by . This book was released on 1989 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Static Aeroelastic Analysis of the ARW 2 Wing Including Correlation with Experiment written by Joseph P. Hepp and published by . This book was released on 2005 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Aircraft Aeroelasticity and Structural Dynamics Research at the NASA Langley Research Center Some Illustrative Results written by and published by . This book was released on 1988 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Computational Aeroelastic Analysis of Aircraft Wings Including Geometry Nonlinearity written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Because the flutter phenomenon of aircraft wings is usually associated with large deformations/deflections, the structural solution based on linear theory for the aircraft wings might give inaccurate or totally unphysical solutions. This is due to the equilibrium state of the structure is referred to the initial configuration, which can be very different with actual configuration at a given time when the wing deflection is large. So the changing geometry of the structure has to be taken into account in order to accurately describe the fluid/structure interactions at the onset of flutter, or in the post-flutter regime. The objective of the present study is to show the ability of solving fluid structural interaction problems more realistically by including the geometric nonlinearity of the structure so that the aeroelastic analysis can be extended into the onset of flutter, or in the post flutter regime. A nonlinear Finite Element Analysis software is developed based on second Piola-Kirchhoff stress and Green-Lagrange strain. The second Piola-Kirchhoff stress and Green-Lagrange strain is a pair of energetically conjugated tensors that can accommodate arbitrary large structural deformations and deflection, to study the flutter phenomenon. Since both of these tensors are objective tensors, i.e., the rigid-body motion has no contribution to their components, the movement of the body, including maneuvers and deformation, can be included. The nonlinear Finite Element Analysis software developed in this study is verified with ANSYS, NASTRAN, ABAQUS, and IDEAS for the linear static, nonlinear static, linear dynamic and ...

Download or read book Linear and Nonlinear Aeroelastic Analysis of a Strut braced Wing written by and published by . This book was released on 2012 with total page 71 pages. Available in PDF, EPUB and Kindle. Book excerpt: The linear and nonlinear aeroelastic characteristics of a Strut-Braced Wing for large transport aircrafts are investigated. The Strut-Braced Wing is a design that goes back to the dawn of aviation and still continues to be widely used in small general aircraft. The concept for using the Strut-Braced Wing for large passenger aircraft has been around since the 1940's, and it has been shown that this wing configuration has several advantages over a conventional cantilever wing. Although several aeroelastic studies have been performed on Strut-Braced Wings, the effects of structural nonlinearities have not been fully investigated. In this study, the linear and nonlinear flutter and divergence speeds are determined for two different configurations. The two configurations were selected to highlight the effect that the joint location has on the aeroelastic results. The first configuration has the lower wing connecting at the midpoint of the upper wing and the second configuration has the lower wing connecting at the tip of the upper wing. The aeroelastic analysis is performed using NASTRAN and an in-house program. It was found that for the first configuration, the geometric nonlinearity significantly affects the aeroelastic performance and an increase of the flutter speed is observed compared to the linear case. The second configuration, the geometric nonlinearity negatively impacts the dynamic aeroelastic stability and the flutter speed is reduced with respect to the linear case. It is concluded that the structural geometric nonlinearity must be included even in the preliminary aeroelastic investigations of this type of configurations to have meaningful evaluation of the aeroelastic response and stability analysis.

Download or read book A CFD CSD Interaction Methodology for Aircraft Wings written by Manoj K. Bhardwaj and published by . This book was released on 1997 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "With advanced subsonic transports and military aircraft operating in the transonic regime, it is becoming important to determine the effects of the coupling between aerodynamic loads and elastic forces. Since aeroelastic effects can contribute significantly to the design of these aircraft, there is a strong need in the aerospace industry to predict these aero-structure interactions computationally. To perform static aeroelastic analysis in the transonic regime, high fidelity computational fluid dynamics (CFD) analysis tools must be used in conjunction with high fidelity computational structural dynamics (CSD) analysis tools due to the nonlinear behavior of the aerodynamics in the transonic regime. There is also a need to be able to use a wide variety of CFD and CSD tools to predict these aeroelastic effects in the transonic regime. Because source codes are not always available, it is necessary to couple the CFD and CSD codes without alteration of the source codes. In this study, an aeroelastic coupling procedure is developed which will perform static aeroelastic analysis using any CFD and CSD code with little code integration. The aeroelastic coupling procedure is demonstrated on an F/A-18 Stabilator using NASTD (an in-house McDonnell Douglas CFD code) and NASTRAN. In addition, the Aeroelastic Research Wing (ARW-2) is used for demonstration of the aeroelastic coupling procedure by using ENSAERO (NASA Ames Research Center CFD code) and a finite element wing-box code (developed as a part of this research). The results obtained from the present study are compared with those available from an experimental stud), conducted at NASA Langley Research Center and a study conducted at NASA Ames Research Center using ENSAERO and modal superposition. The results compare well with experimental data. Parallel computing power is used to investigate parallel static aeroelastic analysis because obtaining an aeroelastic solution using CFD/CSD methods is computationally intensive. A parallel finite element wing-box code is developed and coupled with an existing parallel Euler code to perform static aeroelastic analysis. A typical wing-body configuration is used to investigate the applicability of parallel computing to this analysis. Performance of tile parallel aeroelastic analysis is shown to be poor; however with advances being made in the arena of parallel computing, there is definitely a need to continue research in this area."--Page ii.

Download or read book Static Aeroelastic Effects of Formation Flight for Slender Unswept Wings written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-05-20 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: The static aeroelastic equilibrium equations for slender, straight wings are modified to incorporate the effects of aerodynamically-coupled formation flight. A system of equations is developed by applying trim constraints and is solved for component lift distribution, trim angle-of-attack, and trim aileron deflection. The trim values are then used to calculate the elastic twist distribution of the wing box. This system of equations is applied to a formation of two gliders in trimmed flight. Structural and aerodynamic properties are assumed for the gliders, and solutions are calculated for flexible and rigid wings in solo and formation flight. It is shown for a sample application of two gliders in formation flight, that formation disturbances produce greater twist in the wingtip immersed in the vortex than for either the opposing wingtip or the wings of a similar airplane in solo flight. Changes in the lift distribution, resulting from wing twist, increase the performance benefits of formation flight. A flexible wing in formation flight will require greater aileron deflection to achieve roll trim than a rigid wing. Hanson, Curtis E. Armstrong Flight Research Center AERODYNAMIC CHARACTERISTICS; AEROELASTICITY; FORMATION FLYING; ANGLE OF ATTACK; LIFT; SLENDER WINGS; VORTICES; WING TIPS

Download or read book Aeroelastic Tailoring of Aircraft Wings Using Structural Geometric Features written by Guillaume Francois and published by . This book was released on 2017 with total page 378 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Development of Multi fidelity Aeroelastic Optimization Framework for Flexible Wing Conceptual Design written by Yanxin Huang and published by . This book was released on 2021 with total page 332 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation introduces a framework to carry out the aeroelastic optimization around the steady-state for flexible fixed wings. Such a framework captures geometrical nonlinearities and aerodynamic unsteadiness, which are the challenges in modern aircraft design. This also takes full advantage of structural geometry by integrating multi-fidelity structures with vortex-lattice method (UVLM), allowing effective and accurate multi-stage aircraft design with a variety of aspect ratios. Functions of structural consistency are used to close the gap between multi-stage designs at different fidelity levels. A model update tool is used to ensure structural consistency and allow communications between stages and fidelity levels. In addition, this framework shows its potential to involve more disciplinaries, such as control and stability, by revealing sensitivities with respect to UVLM vorticities and grids.The lower-fidelity aeroelastic model integrates nonlinear strain-based beam elements with UVLM, while the higher-fidelity model integrates nonlinear displacement-based shell elements with UVLM. The resulting aeroelastic models are coupled with a gradient-based method, focusing on overall performance and detailed analysis, respectively. An artificial neural network (ANN) is established for the model update from the lower- to the higher-fidelity structure. It builds a database and performs a statistical approach to address the parameter inequality. Aerodynamic equations are linearized by performing small perturbations and assuming a frozen aerodynamic geometry. The developed UVLM and aeroelastic models are validated by reference models. Analytical aerodynamic sensitivities are verified by the results of finite-difference. In addition, the feasibility of the model update tool is demonstrated by generating a two-dimensional shell and a three-dimensional wing box from original one-dimensional beams. The feasibility of this framework is demonstrated by optimizing a fixed wing under a large upward bending deflection. The impact of different design variables is also observed and discussed. This research illustrates a comprehensive process for an early design of flexible wings. Although the current framework is limited to the incompressible flow and isotropic shell elements, it has the potential to involve more applications with compressibility corrections of UVLM and composite materials.

Download or read book NASA Technical Memorandum written by and published by . This book was released on 1992 with total page 332 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 500 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Monthly Catalogue United States Public Documents written by and published by . This book was released on 1991 with total page 1430 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Monthly Catalog of United States Government Publications written by and published by . This book was released on with total page 1200 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Steady Pressure Measurements on an Aeroelastic Research Wing ARW 2 written by Maynard C. Sandford and published by . This book was released on 1994 with total page 582 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book 34th Aerospace Sciences Meeting Exhibit written by and published by . This book was released on 1996 with total page 522 pages. Available in PDF, EPUB and Kindle. Book excerpt: