Comparison of aerodynamic characteristics provided by wing with bell shaped lift distribution and generalized wings
01 Jan 2019-Vol. 304, pp 02005
TL;DR: In this article, different types of wings are computed by low and high-fidelity methods to compare their aerodynamic characteristics and the goal of optimization is minimization of aerodynamic drag.
Abstract: In this article different wings are computed by low and high-fidelity methods to compare their aerodynamic characteristics. Thanks to the unusual properties of the wing with the bell-shaped lift distribution, several general geometrical variants of the wings were calculated and their results are presented in this work. Three general wings are assumed and their geometry is defined as rectangular, trapezoidal and elliptical. Airspeed, total lift force, shape of airfoil and root chord are defined, and bending moment is assumed as a surrogate model for wing weight. The goal of optimization is minimization of aerodynamic drag.
Citations
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5 citations
01 Jun 2021
TL;DR: In this paper, a review sheds light on the traits behind an albatross's aerodynamic efficiency such as dynamic soaring, bell shaped lift distribution and provides insights into its hereditary posed encodings and evolutions.
Abstract: The aerodynamic efficiency of the albatross has always fascinated researchers and the designing of drones mimicking the albatross's aerodynamic traits have been a major area of interest for the aerospace industry. This review sheds light on the traits behind an albatross's aerodynamic efficiency such as dynamic soaring, bell shaped lift distribution and provides insights into its hereditary posed encodings and evolutions. The soaring techniques have been introduced and discussed along with the albatross's morphology and structure which is responsible for its efficiency. In addition, the albatross's navigational and foraging strategies are briefly discussed to provide a better understanding of the effects of atmospheric conditions on the albatross's flight characteristics and the limitations.
2 citations
03 Aug 2021
TL;DR: In this paper, the authors proposed a wing shape that approximates the front seen parabola ideal wing by streight lines: line 1 touches parabolas at the axis origin and is 25 % of the length of the wing, line 2 is tangent of parablas at the wingtip and cuts the hotizontal line at 50 % of "a", and line 3 is tangant to parabla, cuts horizontal line at 25 % "a" and cuts line 2 at 75 % of ''a'' and 50 % ''h''.
Abstract: The new W wing shape (half wing, with “a”half wingspan and “h” wingtip height) approximates the front seen parabola ideal wing by streight lines: line 1 touches parabola at the axis origin and is 25 % of “a”, line 2 is tangent of parabola at the wingtip and cuts the hotizontal line at 50 % of “a”, and line 3 is tangent to parabola, cuts horizontal line at 25 % of “a” and cuts line 2 at 75 % of “a” and 50 % of “h”. Real W wing approximated very close the ideal parabolic wing. The new W wing gives more lateral and directional stability.
References
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TL;DR: The third edition of Myers, Montgomery and Anderson-Cook's RSM book is much longer but it omits many important issues in RSM and its emphasis is on the analysis of experiments and the evaluation of designs rather than on design issues.
Abstract: (2010). Response Surface Methodology: Process and Product Optimization Using Designed Experiments, 3rd edition. Journal of Quality Technology: Vol. 42, No. 2, pp. 228-230.
120 citations
"Comparison of aerodynamic character..." refers methods in this paper
...As a design procedure a Response surface methodology (RSM) is used [8] in this work....
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01 Dec 1950
TL;DR: In this article, the minimum induced drag of a wing having a given lift and a given span is extended to include cases in which the bending moment to be supported by the wing is also given.
Abstract: The problem of the minimum induced drag of wings having a given lift and a given span is extended to include cases in which the bending moment to be supported by the wing is also given. The theory is limited to lifting surfaces traveling at subsonic speeds. It is found that the required shape of the downwash distribution can be obtained in an elementary way which is applicable to a variety of such problems. Expressions for the minimum drag and the corresponding spanwise load distributions are also given for the case in which the lift and the bending moment about the wing root are fixed while the span is allowed to vary. The results show a 15-percent reduction of the induced drag with a 15-percent increase in span as compared with results for an elliptically loaded wing having the same total lift and bending moment.
103 citations
TL;DR: In this paper, a full-scale system of this type should be able to detect wingtip vortices over a runway, and the laser wavelength should be selected such that the light beams would not transmit through the aircraft windshields.
Abstract: light reaching the photomultiplier. If one beam is unaffected but the other is deflected in the vertical plane, a smaller net change in the photomultiplier current would result. In full-scale operation over a runway, the laser beams should propagate above and parallel to the runway. Existing runway approach light towers on both ends of the runway could be used to house the necessary system of mirrors. This would not, therefore, add any new protruding structures adjacent to the runway. The beam separation and height above ground are variables which must be determined for best system response to a vortex. For safety, the laser wavelength should be selected such that the light beams would not transmit through the aircraft windshields. The laboratory tests described above indicate that, in principle, a full-scale system of this type should be able to detect wingtip vortices over a runway.
51 citations
01 Jan 1961
TL;DR: In this article, the authors show that the elliptical Auftriebsverteilung of a Tragflugel gegebenen Auftriebes erhalt man bei vorgeschriebener Spannweite den geringsten induzierten Widerstand.
Abstract: Fur einen Tragflugel gegebenen Auftriebes erhalt man bei vorgeschriebener Spannweite den geringsten induzierten Widerstand, wenn man den Auftrieb nach einer Halbellipse verteilt. Die Nebenbedingung, das die Spannweite vorgeschrieben ist, ist dabei aber durchaus wesentlich, und es ist also die Behauptung durchaus unzulassig, das die elliptische Auftriebsverteilung die beste schlechthin sei. Der induzierte Widerstand ist um so kleiner, je groser die Spannweite gemacht wird. Wenn in einem Sonderfall die Spannweite des Flugzeuges durch die Forderung begrenzt wird, das das Flugzeug durch ein bestimmtes vorgegebenes Hallentor geschoben werden kann, so ist es am Platz, innerhalb der so vorgeschriebenen Spannweite den Auftrieb elliptisch zu verteilen. Wenn aber eine derartige Begrenzung nicht vorliegt, dann wird man sich nach anderen Gesichtspunkten richten mussen. Eine beliebige Vergroserung der Spannweite verbietet sich durch das in diesem Fall allzu stark anwachsende Holmgewicht. Eine den flugtechnischen Belangen gerecht werdende Formulierung der Aufgabe ware wohl die, das nicht das dem Auftrieb gleiche Gesamtgewicht, sondern das Gewicht der nichttragenden Teile als vorgegeben anzusehen ist, und das nun diejenige Gestaltung des Flugels gesucht wird, durch die der gesamte Flugelwiderstand (induzierter plus Profilwiderstand), in dem sich das Holmgewicht mit auswirkt, ein Minimum wird. Es ware sehr schwierig, diese Aufgabe etwa als Variationsproblem zu formulieren.
42 citations
"Comparison of aerodynamic character..." refers background or methods in this paper
...Several years later, he conceded the previous conclusion leads to an invalid result, there was a superior spanload solution that maximizes efficiency for a given bending moment [2] His new bell-shaped spanload creates a wing that is 11 percent more efficient and has 22 percent greater span....
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...† Taken over reference [2] ‡ Taken over reference [3] Then a Kutta-Joukovsky law is used to determine local circulation ΓΓ....
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...† Taken over reference [2] ‡ Taken over reference [3]...
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TL;DR: In this paper, the span-wise aerodynamic loading of a wing with minimum induced drag was derived for prescribed lift and root-bending moment, in the case that the lift and its moment of inertia about the longitudinal axis of the aircraft are given.
Abstract: The spanwise aerodynamic loading of wings having minimum induced drag is derived for prescribed lift and root-bending moment. THis problem is an alternative to Prandtl's solution for the case that the lift and its moment of inertia about the longitudinal axis of the aircraft are given.
32 citations