scispace - formally typeset
Search or ask a question
Topic

Lift-induced drag

About: Lift-induced drag is a research topic. Over the lifetime, 2861 publications have been published within this topic receiving 41094 citations.


Papers
More filters
Proceedings ArticleDOI
08 Jan 2007
TL;DR: The results from the third AIAA Drag Prediction Workshop using the unstructured mesh Reynolds averaged Navier-Stokes (RANS) solver NSU3D are presented in this article.
Abstract: Results from the third AIAA Drag Prediction Workshop using the unstructured mesh Reynolds averaged Navier-Stokes (RANS) solver NSU3D are presented. Computations include a grid convergence study on a transonic wing-body and wing-body-fairing configuration at a fixed CL condition using grids up to 41 million points, as well as an incidence sweep (drag polar) at fixed Mach and Reynolds number. A second set of results on a pair of closely related wing geometries is also described, including a grid convergence study at fixed incidence, and an incidence sweep (drag polar) for both wing geometries. For all cases, approximate second-order accurate grid convergence characteristics are demonstrated, with overall accuracy and eciency comparable to other structured, overset, and unstructured workshop calculations. However, it is found that diering grid converged results may be inferred based on dierent families of self-similar coarse and fine grid sequences, particularly for values such as absolute drag at fixed incidence. More consistent grid convergence for idealized drag values (omitting induced drag) is observed, thus validating the procedure of performing grid convergence studies at fixed CL. These grid convergence issues are attributed to the large range of disparate scales which must be resolved in aerodynamic flows, and point to the need for further advances in quantifying and resolving discretization errors for such problems. Over the last five years, the AIAA Applied Aerodynamics Committee has sponsored three Drag Prediction Workshops (DPW), with the aim of assessing the state-of-the-art of current Computational Fluid Dynamics (CFD) solvers at predicting absolute and incremental drag changes on generic transonic transport aircraft configurations.

44 citations

01 Sep 1986
TL;DR: The integral conservation laws of fluid mechanics are used to assess the drag efficiency of lifting wings, both CTOL and various out-of-plane configurations as mentioned in this paper, and it is strongly recommended that an integrated aerodynamic/structural approach be taken in the design of (or research on) future out ofplane configurations.
Abstract: The integral conservation laws of fluid mechanics are used to assess the drag efficiency of lifting wings, both CTOL and various out-of-plane configurations. The drag-due-to-lift is separated into two major components: (1) the induced drag-due-to-lift that depends on aspect ratio but is relatively independent of Reynolds number; (2) the form drag-due-to-lift that is independent of aspect ratio but dependent on the details of the wing section design, planform and Reynolds number. For each lifting configuration there is an optimal load distribution that yields the minimum value of drag-due-to-lift. For well designed high aspect ratio CTOL wings the two drag components are independent. With modern design technology CTOL wings can be (and usually are) designed with a drag-due-to-lift efficiency close to unity. Wing tip-devices (winglets, feathers, sails, etc.) can improve drag-due-to-lift efficiency by 10 to 15% if they are designed as an integral part of the wing. As add-on devices they can be detrimental. It is estimated that 25% improvements of wing drag-due-to-lift efficiency can be obtained with joined tip configurations and vertically separated lifting elements without considering additional benefits that might be realized by improved structural efficiency. It is strongly recommended that an integrated aerodynamic/structural approach be taken in the design of (or research on) future out-of-plane configurations.

44 citations

Journal ArticleDOI
TL;DR: The scaling laws in the geometry, velocity, and power for flapping flyers, for example, birds, and fixed-wing aircraft are discussed from a comparative point of view, and the aerodynamic implications of the scaling, particularly on the lift-to-drag ratio, flapping span efficiency, induced drag, parasite drag, and propulsive efficiency are explored.
Abstract: The scaling laws in the geometry, velocity, and power for flapping flyers, for example, birds, and fixed-wing aircraft are discussed from a comparative point of view, and the aerodynamic implications of the scaling, particularly on the lift-to-drag ratio, flapping span efficiency, induced drag, parasite drag, and propulsive efficiency are explored. The results shed insights into flapping flight and provide a useful guideline for the preliminary design of a flapping-flight vehicle.

44 citations

Journal ArticleDOI
TL;DR: The multidisciplinary design optimization of a strut-braced wing (SBW) aircraft and its benefits relative to a conventional cantilever wing configuration are presented.
Abstract: The multidisciplinary design optimization of a strut-braced wing (SBW) aircraft and its benefits relative to a conventional cantilever wing configuration are presented. The multidisciplinary design team is divided into aerodynamics, structures, aeroelasticity, and the synthesis of the various disciplines. The aerodynamic analysis uses simple models for induced drag, wave drag, parasite drag, and interference drag. The interference drag model is based on detailed computational fluid dynamics analyses of various wing-strut intersections. The wing structural weight is calculated using a newly developed wing bending material weight routine that accounts for the special nature of SBWs. The other components of the aircraft weight are calculated using a combination of NASA's flight optimization system and Lockheed Martin aeronautical systems formulas. The SBW and cantilever wing configurations are optimized using design optimization tools (DOT) software

44 citations

Journal ArticleDOI
TL;DR: In this paper, an extension of these results to delta wings with swept-back or swept-forward trailing edges is presented, and a discussion is given of the drag due to lift.
Abstract: In recently published papers the authors have discussed the problem of drag of delta wings with straight trailing edges and also the lift of this type of wing. The present paper consists of an extension of these results to delta wings with swept-back or swept-forward trailing edges. Drag at zero lift for two slope surfaces and lift is computed for these airfoils, and a discussion is given of the drag due to lift. Centers of pressure are also computed. In addition, some results for drag of wings with three slope surfaces are given. Discussion is made of optimum design from the standpoint of leading and trailing edge angles, and location of maximum thickness. I t is shown that considerable improvements over two-dimensional airfoil performance can be obtained. Results are presented in the form of conventional engineering coefficients.

44 citations


Network Information
Related Topics (5)
Reynolds number
68.4K papers, 1.6M citations
76% related
Laminar flow
56K papers, 1.2M citations
73% related
Boundary layer
64.9K papers, 1.4M citations
72% related
Vortex
72.3K papers, 1.3M citations
72% related
Nozzle
158.6K papers, 893K citations
70% related
Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202344
2022105
202138
202046
201944
201849