3 edition of Divergence study of a high-aspect ratio, forward-swept wing found in the catalog.
Divergence study of a high-aspect ratio, forward-swept wing
1986 by National Aeronautics and Space Administration, Langley Research Center, For sale by the National Technical Information Service in Hampton, Va, [Springfield, Va .
Written in English
|Other titles||Divergence study of a high aspect ratio, forward swept wing.|
|Statement||Stanley R. Cole.|
|Series||NASA technical memorandum -- 87682.|
|Contributions||Langley Research Center.|
|The Physical Object|
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Divergence study of a high-aspect-ratio, forward swept wing. Stanley R. Cole ; Stanley R. Cole. NASA Langley Research Center, Hampton, Virginia.
Comment Divergence study of a high-aspect ratio 'Divergence study of a high-aspect ratio, forward swept wing' William P. Rodden ; Forward-swept wing book of Aircraft Vol.
26, No. 8 August Cited by: 9. A study has been conducted in the NASA-Langley Transonic Dynamics wind tunnel to determine the divergence characteristics of a high aspect ratio forward swept wing of rectangular planform, for sweep angles of zero,and : Stanley R.
Cole. The 15O and 30° forward-swept models experienced divergence instabilities. The O forward-swept model experienced a flutter instability at Hz that had the appearance of a second wing bending mode. (A node line existed near the wing tip.) This instability agrees with the cal- culated hump mode.
Comment on 'Divergence study of a high-aspect ratio, forward swept wing' William P. Rodden ; William P. Rodden. La Canada Flintridge, Flintridge, California. Search for more papers by this author High aspect ratio forward sweep for transport by: 2.
Divergence study of a high-aspect ratio, forward-swept wing [microform] Responsibility Stanley R. Cole. Imprint Airplanes > Wings > Testing. Bibliographic information.
Reprint/reissue date Original date Note Distributed to depository libraries in microfiche. Reproduction. Divergence study of a high-aspect-ratio, forward swept wing By Stanley R. Cole Divergence study of a high-aspect ratio AIRCRAFT DESIGN, TESTING AND PERFORMANCEAuthor: Stanley R.
Cole. NASA Technical Memorandum DIVERGENCE STUDY OF A HIGH-ASPECT RATIO) FORWARD-SWEPT WING STANLEY R. COLE JUNE Isogai  conducted an experimental study on the transonic flutter/divergence characteristics of aeroelastically tailored and non-tailored high-aspect-ratio forward-swept forward-swept wing book.
Figure 1 shows the planform and structure of the 1/scale aeroelastic Divergence study of a high-aspect ratio tunnel model  for the wing of a hypothetical seat transport.
The effect of change of wing camber due to wing bending in the case of an average wing is to increase the reversal speed by not more than 5 per cent. forward-swept wing book Wing divergence is not liable to be serious for swept-back wings, as the wing bending provides a stabilising effect, but wilI he serious for a forward-swept wing book wing.
The static aeroelastic torsion divergence problem is the main obstacle to bring forward swept wing into massive applications. The aeroelastic tailoring technique-based radial basis function neural networks (RBFNNs) and genetic algorithm (GA) optimization in MATLAB considering the material orientation, thickness, and lay-up Divergence study of a high-aspect ratio elucidated in the present by: 1.
optimization we quantify the beneﬁts of a tow steered composite wing box when compared to an unsteered composite wing box. Method In order to quantify the beneﬁts of passive load alleviation, it is necessary to consider the coupling between aero-dynamics and structural deformation that is particularly strong in high aspect ratio wings.
Get this from a library. Divergence study of a high-aspect ratio, forward-swept wing. [Stanley R Cole; Langley Research Center.]. Aeroelastic Analysis and Optimization of High-aspect-ratio Composite Forward-swept Wings.
This paper-presents the results of a design study aiming to optimize wings with typical forward-swept angles and skin ply-orientation in Divergence study of a high-aspect ratio aeroelastic way by using the genetic/sensitivity-based hybrid algorithm.
Under the conditions of satiated Cited by: 6. Thus, in order to gain confidence in Weisshaar's conclusion, experimental verification should be pursued.
The purpose of the present study is to examine the effects of aeroelastic tailoring on the transonic flutter and divergence characteristics of a transport-type high-aspect-ratio forward-swept by: 7. Aeroelastic tailoring of a composite forward-swept wing model is investigated to achieve a minimum structure weight with increasing divergence speed and Divergence study of a high-aspect ratio speed.
*The swept wing also has several more problems. One is that for any given length of wing, the actual span from tip-to-tip is shorter than the same wing that is not swept. Low speed drag is strongly correlated with the aspect ratio, the span compared to chord, so File Size: 2MB.
In this work, a reference regional aircraft wing structural layout is designed to ensure structural integrity for a load limit of g's. A scaled model that represents well the aeroelastic behavior is required for wind tunnel testing to evaluate the nonlinear behavior that can occur in high aspect ratio Size: 2MB.
This banner text can have markup. web; books; video; audio; software; images; Toggle navigation. Elementary aeroelasticity L t AC Fig. Determination of wing divergence speed (two-dimensional case).
two-dimensional flow, as shown in Fig. The torsional stiffness of the wing, which we shall represent by a spring of stiffness K, resists the moment of the lift vector, L, and the wing pitching moment Mo, acting at the aerodynamic centre of the wing.
Nonlinear aeroelasticity of high-aspect-ratio wings excited by time-dependent thrust. Nonlinear Dynamics, Vol. 75, Issue. 3, p. This book will certainly appeal to mathematically inclined students.' Source: The Aeronautical Journal. Aa; T. “ Divergence of Forward Swept Composite Wings,” Journal of Aircraft, Vol.
17, No. 6 Cited by: We study flutter and divergence of isotropic tapered plate couple aerodynamic and structural models using finite element shape develop a MATLAB code to implement the proposed present model is validated using benchmark effects of taper ratio on divergence and flutter are : MahranMohamed, NegmHani, El-SabbaghAdel.
Divergence Study of a High-Aspect-Ratio, Forward Swept Wing Stanley R. Cole* NASA Langley Research Center, Hampton, Virginia Introduction THE present study was conducted to obtain data that could be used to assess the prediction capabilities of a currently available aeroelastic code for a high-aspect-ratio, forward-swept wing.
The wings illustrated in figures 11 and 12 are swept back, as are most of the wings seen on operational aircraft. But, according to the simple theory in which the streamwise velocity is resolved into components normal and parallel to the leading edge of the wing, the wing could just as well be swept forward.
Start studying Ornithology. Learn vocabulary, terms, and more with flashcards, games, and other study tools. ratio of body weight to wing area.
relationship between wing span and wing width narrower wing- high aspect ratio. nares. Nostrils. air sacs. sacks of tissue that run through the chest, usually 9, cushion internal organs, help in. AOE Aeroelasticity and Wing Divergence Aerospace Structures Page 3 of 6 (8) A plot of versus the angle of attack obtained from equation (8) is shown in Figure 2.
From equation (8) we see that as for. That is, the angle of attack grows without bound as. Of course, this excessive twist is a theoretical Size: KB. In the experimental study on the transonic flutter/divergence characteristics of the aeroelastically tailored and non-tailored high-aspect-ratio forward swept wings, an unusual flutter phenomenon was observed for the non-tailored wing .
The phenomenon has been confirmed qualitatively as "Shock-Stall Flutter" by the numerical simulation using. Divergence is a phenomenon in which the elastic twist of the wing suddenly becomes theoretically infinite, typically causing the wing to fail. Control reversal is a phenomenon occurring only in wings with ailerons or other control surfaces, in which these control surfaces reverse their usual functionality (e.g., the rolling direction associated with a given aileron moment is reversed).
Divergence. Divergence occurs when a lifting surface deflects under aerodynamic load. Effects of aspect ratio, sweep angle, and stacking sequence of laminated composites were studied to find the optimized configuration of an aeroelastically tailored composite wing idealized as a flat plate in terms of flutter speed.
The aeroelastic analysis has been carried out in the frequency domain. The modal approach in conjunction with doublet-lattice method (DLM) has been chosen for Cited by: 7.
Effects of aspect ratio, sweep angle, and stacking sequence of laminated composites were studied to find the optimized configuration of an aeroelastically tailored composite wing idealized as a flat plate in terms of flutter speed.
The aeroelastic analysis has been carried out in the frequency domain. The modal approach in conjunction with doublet-lattice method (DLM) has been chosen for.
One of the drawbacks of forward swept wings is the increased chance of divergence, an aeroelastic consequence of lift force on forward swept wings twisting the tip upwards under increased lift.
On a forward-swept design, this causes a positive feedback loop that increases the angle of incidence at the tip, increasing lift and inducing further deflection, resulting in yet more lift and additional changes in.
elastic wing with variable sweep was designed and subcritically tested for aeroelastic divergence in the Virginia Tech six foot stability wind tunnel.
This wing has an internal interchangeable graphite/epoxy plate that provides the wing stiffness. This plate had the shape of a high aspect ratio trapezoid. We will examine the divergence of a symmetrical, two-dimensional airfoil restrained by a rotation spring as sketched in Figure 1.
Aerodynamic force causes an elastic angle of attack a corresponding to structural twisting of a real wing. To ﬂnd the relationship between ﬁand airspeed V (or dynamic pressure q = 1 2 ‰V 2 1), we sum the. The study of aerodynamics is a complicated and pilots should consider the task of learning aerodynamics as critical as learning how to land safely.
Aerodynamics of Flight Chapter 3. Figure Vector components of lift, drag, and weight (gravity). (This dimensionless number is the ratio of lift pressure to dynamic pressure and area. Thus, proper aero-elastic tailoring is necessary to lessen the severity of the aero-elastic divergence problem of such wing configuration.
This research paper presents a model for aeroelastic optimization of an idealized, composite, swept, plate wing with high aspect ratio. Çiçek, Gökçen, and Kayran, Altan. "Aeroelastic Modeling and Analysis of High Aspect Ratio Wings With Different Fidelity Structural Models." Proceedings of the ASME International Mechanical Engineering Congress and Exposition.
Volume 1: Advances in Aerospace Technology. Salt Lake City, Utah, USA. November 11–14, VT03A ASME. characteristics for the forward swept wing are less in values compared with the swept back wing, therefore a forward swept wing can fly at higher speed corresponding to a pressure distribution associated for lower speed.
key words: Forward, Swept angles, Wing, Aerodynamic characteristics. Start studying BASIC PHYSICS. Learn vocabulary, terms, and more with flashcards, games, and other study tools. Search. A WING WITH A VERY HIGH ASPECT RATIO (IN COMPARISON WITH A LOW ASPECT RATIO WING) WILL HAVE.
tailorfiij of forward swept wing structures. Reference 1 describes, in detail, the background of the forward swept wing concept and,in addition, presents an A1gebraic expression relating the divergence speed of swept wings to the geometric, aerodynamic anid structural parameters of such by: tailoring involving bending-torsion coupling was seen to be effective for high-aspect ratio wings as well as low-aspect ratio wings.
In the same year, Sherrer et al.  demonstrated the principle of aeroelastic tailoring with advanced composite materials to increase the divergence speed of a forward-swept wing through low-speed wind tunnel tests.
If you are modelling a single phase low Reynolds number flow then you can use high aspect ratio elements and big expansion ratioes and it will work fine.
If you are simulating surface tension in free surface models you have extremely strict limits on mesh quality -. obtained in ﬂight pdf the XA airplane (a forward-swept-wing demonstrator) for Mach pdf (M) from to Most of the data were obtained near an altitude of 30, ft.
A representative Reynolds num-ber, for M = and a pressure altitude of 30, ft, is based on the mean aerodynamic chord.
The XA data (forward-swept wing) are.Mathematically the limit of a very low aspect ratio is a 2D download pdf moving through unconstrained medium. How high an AR can go is mainly dictated by structural soundness of the wing.
For real aircraft, have a look at the classic example of a low aspect ratio wing - F Typical high aspect ratio. Torsional divergence is usually ebook with high aspect ratio wings with insufficient torsional stiffness.
I am not familiar with the DVIII wing, but if the wing had a plywood covering as stated by Cigogne, it seems as though the DVIII wing would have had a relatively high torsional stiffness.