A General Approach to Lifting-Line Theory, Applied to Wings with Sweep

Reid, Jackson T.; Hunsaker, Douglas F.

doi:10.2514/6.2020-1287

Cited by 13 publications

(4 citation statements)

References 25 publications

(36 reference statements)

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“…MachUpX is a Python implementation of the Goates-Hunsaker (G-H) general numerical lifting-line method, which is a modern extension of Prandtl's classical lifting-line theory [26][27][28]. Within the G-H method, the wing is replaced by a set of horseshoe vortices and Prandtl's lifting-line hypothesis is enforced at a single control point on each vortex to determine the aerodynamics of the wing.…”

Section: Numerical Lifting-line Solution (Machupx)mentioning

confidence: 99%

“…Next, we aligned and simplified each extracted wing shape (n = 1031) and connected these wings to a gull-shaped body (figure 1b). With each final wing-body configuration, we predicted the aerodynamic properties using MachUpX, a low-order numerical general lifting-line model (figure 1c) [26][27][28]. We validated the outputs from MachUpX with experimental wind tunnel measurements on 3D-printed half-span equivalent wing-body models (figure 1d).…”

Section: Introductionmentioning

confidence: 99%

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Gull-inspired joint-driven wing morphing allows adaptive longitudinal flight control

Harvey

Baliga

Goates

et al. 2021

J. R. Soc. Interface.

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Birds dynamically adapt to disparate flight behaviours and unpredictable environments by actively manipulating their skeletal joints to change their wing shape. This in-flight adaptability has inspired many unmanned aerial vehicle (UAV) wings, which predominately morph within a single geometric plane. By contrast, avian joint-driven wing morphing produces a diverse set of non-planar wing shapes. Here, we investigated if joint-driven wing morphing is desirable for UAVs by quantifying the longitudinal aerodynamic characteristics of gull-inspired wing-body configurations. We used a numerical lifting-line algorithm (MachUpX) to determine the aerodynamic loads across the range of motion of the elbow and wrist, which was validated with wind tunnel tests using three-dimensional printed wing-body models. We found that joint-driven wing morphing effectively controls lift, pitching moment and static margin, but other mechanisms are required to trim. Within the range of wing extension capability, specific paths of joint motion (trajectories) permit distinct longitudinal flight control strategies. We identified two unique trajectories that decoupled stability from lift and pitching moment generation. Further, extension along the trajectory inherent to the musculoskeletal linkage system produced the largest changes to the investigated aerodynamic properties. Collectively, our results show that gull-inspired joint-driven wing morphing allows adaptive longitudinal flight control and could promote multifunctional UAV designs.

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Section: Numerical Lifting-line Solution (Machupx)mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Gull-inspired joint-driven wing morphing allows adaptive longitudinal flight control

Harvey

Baliga

Goates

et al. 2021

J. R. Soc. Interface.

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“…Recently, Goates et al [23] and Reid [24] also observed this phenomenon and proposed a more sophisticated lifting-line approach able to grid converge for non-straight wings. Such approach is however out of the scope of this work, as this result does not imply a strict value judgement about the method relevance.…”

Section: Grid Convergencementioning

confidence: 89%

An Efficient 3D Non-Linear Lifting-Line Method with Correction for Post-Stall Regime

Simonet,

Roncin,

Faure

et al. 2024

Preprint

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The ongoing development of low order methods providing fast estimations of aerodynamic loading are essential for pre-dimensioning and optimization of wings and fins. The aim of this study is to present an efficient 3D Non-Linear Lifting-Line Method enhanced by an artificial viscosity correction, able to give reliable results for post-stall regime, where conventional lifting-line methods usually fail. In the present method, the lifting-line governing equation is solved by a Newton-Raphson algorithm, with an analytical Jacobian matrix. An artificial viscosity term has been added to the governing equation, in order to regularize the solution for post-stall regime. A unique parameter was defined to control the amount of artificial viscosity introduced in the governing equation. The investigations focus on the influence of the amount of artificial viscosity on the regularization of the final solution. The perturbation generated by the artificial viscosity on the governing equation is also analyzed. The method has been validated and evaluated with linear and non-linear test cases, from analytical and experimental data from the literature. It was shown that there is an optimal amount of artificial viscosity leading to a converged solution, for post-stall regime, associated with smooth circulations along the wing span, coherent 3D lift coefficients, and low deviations from the initial governing equation. When the amount of artificial viscosity increases beyond this optimal value, the solution deteriorates. The optimal value of the parameter controlling the amount of artificial viscosity has been found to be practically insensitive to the angle of attack, and to the wing discretization.

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“…The ILL method requires the lifting line to (i) pass through the quarter of the chord of the wing and (ii) be orthogonal to that chord at each of its points. Condition (i) is generally part of the formulation of the lifting line methods, where the line is the locus of the aerodynamic center of the wing [37,38]. Furthermore, in aerodynamic polars, the aerodynamic moment is typically defined about the quarter of the chord, since the aerodynamic forces produce a constant moment about this point in the case of a symmetric airfoil.…”

Section: Couplingmentioning

confidence: 99%

Model coupling biomechanics and fluid dynamics for the simulation of controlled flapping flight

Colognesi¹,

Ronsse²,

Chatelain³

2021

Bioinspir. Biomim.

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This paper proposes a multiphysics computational framework coupling biomechanics and aerodynamics for the simulation of bird flight. It features a biomechanical model based on the anatomy of a bird, which models the bones and feathers of the wing. The aerodynamic solver relies on a vortex particle-mesh method and represents the wing through an immersed lifting line, acting as a source of vorticity in the flow. An application of the numerical tool is presented in the modeling of the flight of a northern bald ibis (Geronticus eremita). The wing kinematics are imposed based on biological observations and controllers are developed to enable stable flight in a closed loop. Their design is based on a linearized model of flapping flight dynamics. The controller solves an underdetermination in the control parameters through minimization. The tool and the controllers are used in two simulations: one where the bird has to trim itself at a given flight speed, and another where it has to accelerate from a trimmed state to another at a higher speed. The bird wake is accurately represented. It is analyzed and compared to the widespread frozen-wake assumption, highlighting phenomena that the latter cannot capture. The method also allows the computation of the aerodynamic forces experienced by the flier, either through the lifting line method or through control-volume analysis. The computed power requirements at several flight speeds exhibit an order of magnitude and dependency on velocity in agreement with the literature.

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A General Approach to Lifting-Line Theory, Applied to Wings with Sweep

Cited by 13 publications

References 25 publications

Gull-inspired joint-driven wing morphing allows adaptive longitudinal flight control

Gull-inspired joint-driven wing morphing allows adaptive longitudinal flight control

An Efficient 3D Non-Linear Lifting-Line Method with Correction for Post-Stall Regime

Model coupling biomechanics and fluid dynamics for the simulation of controlled flapping flight

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