scispace - formally typeset
Search or ask a question
Topic

Vortex lattice method

About: Vortex lattice method is a research topic. Over the lifetime, 779 publications have been published within this topic receiving 9242 citations.


Papers
More filters
Book ChapterDOI
01 Jan 1988
TL;DR: In this article, potential flow methods represent a suitable way to calculate wing-vortex interactions and in many cases lead to simpler mathematical structures than Euler methods, if viscous and turbulent effects are negligible.
Abstract: Flow interferences between wings and free vortex sheets (e.g. canard-wing with vortex separation) can influence the aerodynamic characteristics of a configuration to a considerable extent. If viscous and turbulent effects are negligible, potential flow methods represent a suitable way to calculate wing-vortex interactions and in many cases lead to simpler mathematical structures than Euler methods.

3 citations

17 Jul 2015
TL;DR: In this article, an automatic, fast-turnaround, non-empirical aircraft cabin sizing method, hereafter called Cabin Configurator, has been developed that places all the required elements within aircraft cabins The dimensions in which the elements are fitted can be automatically sized by the method itself (inside-out approach) but can also be pre-defined by the designer (outside-in approach) Other key differences with existing design methods are the ability to cope with arbitrary cabin shapes such as the trapezium-like blended-wing-body cabin and to exchange seats for
Abstract: Considering the fact that all large commercial aircraft have not changed significantly in their tube–and–wing shape during the past few decades, one would suggest that a completely different configuration is necessary to facilitate a new leap forward in aircraft performance The blended–wing–body is potentially such an alternative configuration Existing conceptual design methodologies do not always apply to these configurations since they are often based on empirical relations for, or intensively tailored towards, tube–and–wing configurations Developing new conceptual design methodologies for the interior and exterior design and analysis of these blended–wing–body configurations forms the main objective of this study An automatic, fast–turnaround, non–empirical aircraft cabin sizing method, hereafter called Cabin Configurator, has been developed that places all the required elements within aircraft cabins The dimensions in which the elements are fitted can be sized automatically by the method itself (inside–out approach) but can also be pre–defined by the designer (outside–in approach) Other key differences with existing design methods are the ability to cope with arbitrary cabin shapes such as the trapezium–like blended–wing–body cabin and to exchange seats for galleys and lavatories The Cabin Configurator has been extensively validated against a large amount of existing tube–and–wing cabins The average underestimation of the cabin length and cabin width for widebody configurations is found to be 78% and 44% respectively For narrowbody configurations, the overestimation of the cabin length is found to be 52% where the cabin width is underestimated by 19% No conclusions could be derived about the feasibility of Cabin Configurator results for blended–wing–body cabins due to the lack of well–documented cabin designs in the research field A fast–turnaround aerodynamic analysis method, hereafter called BWB–Q3D, has also been developed that analyses the wing and fuselage exterior of a blended–wing–body configuration from an aerodynamic perspective The three–dimensional lift and drag coefficients are estimated by the combination of a vortex lattice method with a two–dimensional airfoil analysis method An important consideration in the BWB–Q3D methodology is setting the sectional sweep angles of the fuselage to zero, leading to conservative estimations of the drag coefficients BWB–Q3D has been validated with high–fidelity computational fluid dynamics based on the Reynolds–averaged Navier–Stokes equations Firm conclusions on the magnitude of the results could not be given However, a good correlation in global design trends of lift–over–drag ratios has been observed between the results of BWB–Q3D and the high–fidelity computational fluid dynamics Computations were performed in cruise conditions (Mach 07, Mach 075 and Mach 08) on two different geometries An extensive analysis of blended–wing–body cabin–sizing approaches has been performed in order to determine the differences in accuracy in a worst-case scenario The inside–out approach of the Cabin Configurator has been compared with the tube–and–wing–tailored outside–in approach, often pursued in the research field In analyzing several thousands of cabins, it has been shown that an average overestimation between 7% and 22% in cabin capacity results from following the outside–in design approach Finally, a new aircraft cabin sizing method has been outlined, the hybrid approach, based on combining cabin width dimensioning with pre–defined cabin length determination An average decrease of more than 50% in cabin area sizing error is obtained when following this method instead of outside-in No dedicated interior–sizing tool such as the Cabin Configurator is required, making this method easily applicable within the blended–wing–body research field

3 citations

Proceedings ArticleDOI
13 Jun 2016
TL;DR: In this article, a method is developed to approximate the root aerofoil design to achieve straight isobars on a wing of any given shape, within computational times that are suitable for conceptual design.
Abstract: For modern transonic transport aeroplanes, it is important to produce low drag at high cruise speeds. The root effect, caused by effects of symmetry on swept wings, decreases the performance of these aeroplanes. During aeroplane design, root modifications are applied to counteract this decrease in performance. Most conceptual aeroplane design tools do not have a method for design of the root aerofoil. However, the design of the root aerofoil has a significant influence on the properties of the final design, since it transfers the loads from the wing to the fuselage. Therefore, having a conceptual method for design of the wing root aerofoil will increase the accuracy of a conceptual aeroplane design. For conceptual design, computational times are important, to allow the designer to try different approaches and get a feel for the design. In this report a method is developed to approximate the root aerofoil design to achieve straight isobars on a wing of any given shape, within computational times that are suitable for conceptual design. First a method is developed for estimating the pressure distribution over the root aerofoil of a given wing. This is done by combining a method for estimation of the root effect due to thickness, a method for estimation of the root effect due to lift, a Vortex Lattice Method (VLM) and a two-dimensional panel method. A full potential method, MATRICS-V, is used to verify the results of the method, because of its proven validity. It is shown that the results of the first part of the method are generally in good agreement with results found by MATRICS-V. The effects of wing sweep, wing taper and addition of a wing kink can be modelled with results that are in good agreement with the verification data. For aft swept wings with positive lift, the pressure near the leading edge is underestimated. For forward swept wings with positive lift, the pressure on the upper surface is overestimated. For wings with a cambered aerofoil an inaccuracy occurs over the forward part of the profile. The general shape of the curve, however, is captured. Secondly, this method is coupled with an optimisation method for the root aerofoil, using Class-Shape function Transformation (CST) parametrisation. The target of the optimisation is set to achieve a similar pressure distribution over the wing root aerofoil as the pressure distribution over the outboard section of the wing. For the developed method, it is difficult to show that the results are valid, since there is no method that has a one-to-one match with the method developed. Therefore, the results are compared to the general characteristics observed in actual root aerofoil designs. The method shows the characteristic behaviour in terms of change in camber, change in location of maximumthickness and change in incidence angle. The increase in thickness, however, is not present. This is caused by the fact that the lower surface pressure distribution is also set as a target. In actual aeroplane design the lower surface is of less importance. In the method developed, however, it is of importance to retain the shape of specific aerofoil designs, like supercritical aerofoils, during optimisation. As a final verification, an optimised root aerofoil design is analysed using MATRICS-V. The results show that the root section pressure distribution is in good agreement with the outboard pressure distribution. In terms of computational time, the method is shown to generally produce reliable results within 30 seconds.

3 citations

18 Sep 2013
TL;DR: In this article, an aeroservoelastic model was used to demonstrate the potential of closed-loop load alleviation using aerodynamic control surfaces, which is a geometrically nonlinear composite beam, which was linearised around equilibrium rotating conditions and coupled with a linearised 3D Unsteady Vortex Lattice Method (UVLM) with prescribed helicoidal wake.
Abstract: The increased flexibility of wind turbine blades necessitates not only accurate predictions of the aeroelastic effects, but also requires active control techniques to overcome potentially damaging loadings and oscillations. An aeroservoelastic model, capturing the structural response and the unsteady aerodynamics of very large rotors, will be used to demonstrate the potential of closed-loop load alleviation using aerodynamic control surfaces. The structural model is a geometrically-nonlinear composite beam, which is linearised around equilibrium rotating conditions and coupled with a linearised 3D Unsteady Vortex Lattice Method (UVLM) with prescribed helicoidal wake. This provides a direct higher fidelity solution to BEM for the dynamics of deforming rotors in attached flow conditions. The resulting aeroelastic model is in a state-space formulation suitable for control synthesis. Flaps are modeled directly in the UVLM formulation and LQG controllers are finally designed to reduce fatigue by about 26% in the presence of continuous turbulence. Trade-offs between reducing root-bending moments (RBM) and suppressing the negative impacts on torsion due to flap deployment will also be investigated.

3 citations

Journal ArticleDOI
TL;DR: This paper proposes a variant of gradient-enhanced surrogate model based on polynomial-chaos–kriging (PCK) to assist aerodynamic design exploration and aims to improve the accuracy of kriging.
Abstract: This paper proposes a variant of gradient-enhanced surrogate model based on polynomial-chaos–kriging (PCK) to assist aerodynamic design exploration. The main aim is to improve the accuracy of krigi...

3 citations


Network Information
Related Topics (5)
Aerodynamics
33.3K papers, 460.4K citations
87% related
Drag
43.8K papers, 769.2K citations
76% related
Turbine
106.6K papers, 1M citations
75% related
Reynolds number
68.4K papers, 1.6M citations
75% related
Buckling
30.3K papers, 465.8K citations
74% related
Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20221
202133
202036
201947
201837
201731