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We shall attempt here to summarize the existing data on the values of the low‐speed CLmax. of wings, in the absence of a fuselage, and without including information on stalling incidence or pitching moment. The summary is limited to the consideration of unswept wings, and those of delta plan form, which have symmetrical sections: there is some discussion of the maximum lift increments due to the use of flaps of various kinds.

This study seeks to explore the aerodynamic performance of wings with different shapes at low Reynolds numbers.

The airfoils of these wings are made from aluminum plates, and the maximum cord length and wingspan are 15 cm. Wings A to D are plates with 6 percent Gottingen camber but different wing planforms. The forward‐half sections of wings E and F are dragonfly‐like, whereas the rear‐half sections of wings E and F are flat and positively cambered, respectively. The aspect ratios of these wings are close to one, and the ratios of plate thickness to the maximum cord length are 1.3 percent. Experimental results indicate that the wings with Gottingen camber have a superior lift and lift‐to‐drag ratio, whereas the wings with dragonfly‐like airfoils perform well in terms of drag and pitch moment.

The aerodynamic measurements of the wings demonstrate that the wing with the Gottingen camber airfoil, a swept‐back leading edge and a straight trailing edge is suitable for use in micro aerial vehicle (MAV). An MAV is fabricated with this wing and the aerodynamic performance of the MAV is examined and compared with the bare wing data.

This study develops several criteria to the design of MAV‐sized wings. For example, the thickness ratio of airfoil must be small, usually less than 2 percent. Besides, the airfoil must be cambered adequately. Furthermore, a wing planform with a swept‐back leading edge and a straight trailing edge would be contributive to the successful flights of MAVs.

The purpose of this study is to investigate the aerodynamic characteristics of a low-to-moderate-aspect-ratio, tapered, untwisted, unswept wing, equipped of sheared wing tips.

In this work, wind tunnel tests were made to study the influence in aerodynamic characteristics over a typical low-to-moderate-aspect-ratio wing of a general aviation aircraft, equipped with sheared – swept and tapered planar – wing tips. An experimental parametric study of different wing tips was tested. Variations in its leading and trailing edge sweep angle as well as variations in wing tip taper ratio were considered. Sheared wing tips modify the flow pattern in the outboard region of the wing producing a vortex flow at the wing tip leading edge, enhancing lift at high angles of attack.

The induced drag is responsible for nearly 50% of aircraft total drag and can be reduced through modifications to the wing tip. Some wing tip models present complex geometries and many of them present benefits in particular flight conditions. Results have demonstrated that sweeping the wing tip leading edge between 60 and 65 degrees offers an increment in wing aerodynamic efficiency, especially at high lift conditions. However, results have demonstrated that moderate wing tip taper ratio (0.50) has better aerodynamic benefits than highly tapered wing tips (from 0.25 to 0.15), even with little less wing tip leading edge sweep angle (from 57 to 62 degrees). The moderate wing tip taper ratio (0.50) offers more wing area and wing span than the wings with highly tapered wing tips, for the same aspect ratio wing.

Although many studies have been reported on the aerodynamics of wing tips, most of them presented complex non-planar geometries and were developed for cruise flight in high subsonic regime (low lift coefficient). In this work, an exploration and parametric study through wind tunnel tests were made, to evaluate the influence in aerodynamic characteristics of a low-to-moderate-aspect-ratio, tapered, untwisted, unswept wing, equipped of sheared wing tips (wing tips highly swept and tapered).

The purpose of this paper is to describe the research performed on flexible-wing micro air vehicle (MAV). Typical attributes associated with the aerodynamics of MAVs are low Reynolds number, low altitude flying environments and low aspect ratio platforms. These attributes give birth to several challenges such as poor aerodynamic performance, nonlinear lift patterns and reduced gust tolerance. Flexible-wing MAV is renowned for improved aerodynamic characteristics such as smooth flight in gusty conditions than its rigid-wing counterpart.

The wind-tunnel experiments are carried out for various configurations to determine the ways of further enhancing lift. The baseline geometric description for all MAVs includes 15-cm box dimension and an aspect ratio of 1. The experimental results of the baseline configuration are compared with other experimental results available in literature. After due validation, the effects of following parameters are quantized and compared with the rigid-wing counterpart: underlying skeleton; wing membrane extension; wing membrane relaxation; and wing membrane material (latex, silk, poly-vinyl chloride plastic sheet and nylon).

It is found that the skeleton layout significantly governs the lift characteristics. The effect of membrane extension and relaxation proved to be of little advantage. Latex sheets are found to be the best choice for membrane material. The aerodynamic assessment at low Reynolds number has demonstrated significant improvement of lift characteristics for flexible wings over rigid-wing counterparts.

The results presented in this paper are based on wind-tunnel experimentation. Further experimentation through flight test may be needed to reveal the true aerodynamic performance under unsteady maneuvers.

The material properties vary significantly during fabrication. A technique to standardize the properties of flexible membranes is a missing link in literature and warrants further investigation.

This concept of flexible wing has shown high potential. The primary objective of this paper is to experimentally investigate ways of further enhancing the lift of flexible-wing MAVs by controlling flexibility passively. While various researchers have spent many years on developing the optimum wing frame for the flexible wing, research on different wing materials has been limited. This is the first paper of its kind covering all aspects of wing-frame design, material, effects of extension and relaxation on wing membrane.

IS there anything magic about the shape of a wing section? Asked to sketch the profile of a wing on the back of an envelope, one would have no difficulty in representing a shape which would probably, for most purposes, be adequate. Assuming this generalization to be true—perhaps it is a rather rash one—one might equally well question the need for an article on aerofoil design, or indeed the need for the long and painstaking research which, over the years, has been conducted on this particular subject. But it is this same research which, in the long run, has resulted in the recognition of certain general rules relating to aerofoil geometry, which are now taken so much for granted that they would probably be embodied in one's preconceived notion of what a wing section should look like. Recently, also, rather complicated theoretical techniques have made possible the design of profiles which, if manufactured faithfully and carefully in each detail, can provide a performance which is considerably better than any more arbitrary shaping to general rules would produce. Finally, of course, one must recognize that there are exceptional conditions where the application of conventional ideas is inadvisable, and where theoretical and experimental research is needed to suggest what is more appropriate. This article will be concerned for the most part with amplifying these remarks; but, by and large, it must be admitted at the outset that we cannot point to any revolutionary discontinuities in the progress of aerofoil design such as have characterized advances in the means of aircraft propulsion, or structural design.

WRITING an introduction to an article by Mr S. B. Gates on Trailing‐Edge Flaps, which appeared in these columns in 1937, the Editor felt constrained to admit his bewilderment over the number and variety of types of high‐lift aid which then existed. Without intending any disrespect, I imagine that the progress of years must have added to his embarrassment. It has certainly added to the number of devices in use and under test.

For a delta wing it is not sufficient to consider spanwise bending and chordwise rotation only. Chordwise bending must be added. It is therefore necessary to calculate the aerodynamic coefficients accordingly. The theory of Lawrence and Gerber dealing with aerodynamic coefficients of oscillating delta wings in incompressible flow is extended to give the coefficients at any station of the wing. It is shown that for practical reasons the assumption is made that induction may be neglected. This means that the coefficients are theoretically only correct for a rigid wing in pitching and plunging. However they will be used for a flexible wing with spanwise bending, chordwise bending and rotation. For the oscillating delta wing with subsonic leading edges in supersonic flow the theory of Watkins and Berman will be discussed. Here again the original report is extended to give the coefficients at any station of the wing. The calculation of the natural modes of vibration of the wing, based on the methods of Scanlan and Rosenbaum, is presented for completeness. Finally it is shown how the coefficients and the modes may be combined to give the aerodynamic forces. As an appendix the differences between the British and the American techniques for calculating the aerodynamic coefficients are discussed.

Using the results of earlier investigations, a method for determination of the velocity or pressure distribution and the aerodynamic properties of a low‐aspect‐ratio swept wing with slender body of elliptical cross‐section and vertical tail surface, having arbtrary form, is briefly presented. The method can be used for the prediction of the load distribution, aerodynamic forces and moments on inclined slender wing, body and vertical tail combinations travelling at subsonic or supersonic speeds.

This article deals with some of the stability, control and handling problems that have arisen as a result of drastic changes in aircraft configuration coupled with the advent of supersonic flight at high altitude. The article will be published in two parts. The present part contains a brief introduction to the subject of aircraft stability and control in addition to a description of the longitudinal characteristics of supersonic aircraft. The second part will be published in our next issue, and will deal with the lateral characteristics of supersonic aircraft. Some of the problems encountered in the design of the flying control system for this type of aircraft and an indication of the methods and techniques used for solving the various stability problems are also presented in the second part.

The purpose of this paper is to present a fast, economical and practical method for mathematical modeling of aerodynamic characteristics of rectangular wing in ground (WIG) effect.

Reynolds averaged Navier–Stokes (RANS) equations were converted to Bernoulli equation by reasonable assumptions. Also, Helmbold’s equation has been developed for calculation of the slope of wing lift coefficient in ground effect by defining equivalent aspect ratio (ARe). Comparison of present work results against the experimental results has shown good agreement.

A practical mathematical modeling with lower computational time and higher accuracy was presented for calculating aerodynamic characteristics of rectangular WIG effect. The relative error between the present work results and the experimental results was less than 8 per cent. Also, the accuracy of the proposed method was checked by comparing with the numerical methods. The comparison showed fairly good accuracy.

Aerodynamic surfaces in ground effect were used for reducing wetted surface and increasing speed in high-speed marine and novel aeronautical vehicles.

The proposed method is useful for investigation of aerodynamic performance of WIG vehicles and racing boats with aerodynamic surfaces in ground effect.

The proposed method has reduced the computational time significantly as compared to numerical simulation that allows conceptual design of the WIG crafts and is also economical.