Journal ArticleDOI
Relaxed-Wake Vortex-Lattice Method Using Distributed Vorticity Elements
Götz Bramesfeld,Mark D. Maughmer +1 more
TLDR
In this article, a lifting surface method is presented that uses elements having distributed vorticity to model lifting surfaces and their shed wakes, allowing the representation of a force-free continuous wake-vortex sheet that is free of numerical singularities and is thus robust in its numerical rollup behavior.Abstract:
A lifting-surface method is presented that uses elements having distributed vorticity to model lifting surfaces and their shed wakes. Using such distributed vorticity elements allows the representation of a force-free continuous wake-vortex sheet that is free of numerical singularities and is thus robust in its numerical rollup behavior. Unlike other potential-flow methods that use discrete vortex filaments having solid-core models at their centers to avoid problems with the singularities, the numerical robustness of the new method is achieved without the subsequent solution being dependent on the choice of a cutoff distance or core size. The computed loads compare well with results of classical theory and other potential-flow methods. Its numerical robustness, computational speed, and ability to predict loads accurately make the new method ideal for the investigation of applications in which the loadings on a lifting surface depend strongly on the influence of the wake and its shape, as is the case for the two application examples presented: formation flight and rotating-wing systems.read more
Citations
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Journal ArticleDOI
Applications of the unsteady vortex-lattice method in aircraft aeroelasticity and flight dynamics
TL;DR: The Unsteady Vortex-Lattice Method (UVM) as mentioned in this paper provides a medium-fidelity tool for the prediction of non-stationary aerodynamic loads in low-speed, but high-Reynolds-number, attached flow conditions.
Journal ArticleDOI
Effect of steady and transient wind shear on the wake structure and performance of a horizontal axis wind turbine rotor
Nilay Sezer-Uzol,Oguz Uzol +1 more
TL;DR: In this paper, the effect of free-stream wind shear on the wake structure and performance characteristics of a horizontal axis wind turbine rotor was investigated using a new three-dimensional unsteady vortex-panel method potential flow solver based on a free-vortex wake methodology.
Journal ArticleDOI
Tilt-Wing eVTOL Takeoff Trajectory Optimization
TL;DR: The next generation of self-driving cars will have to contend with the needs of pedestrians, cyclists, and motorcyclists on the roads and in the urban environment.
Proceedings ArticleDOI
Comparison of Aero-Propulsive Performance Predictions for Distributed Propulsion Configurations
Nicholas K. Borer,Joseph M. Derlaga,Karen A. Deere,Melissa B. Carter,Sally A. Viken,Michael D. Patterson,Brandon L. Litherland,Alex M. Stoll +7 more
TL;DR: In this article, the authors compared the results of three different computational flow solvers for selected wing and propulsion geometries, using a common input geometry, but otherwise different input grids and, when appropriate, different flow assumptions.
Proceedings ArticleDOI
Large-Scale Multidisciplinary Optimization of an Electric Aircraft for On-Demand Mobility
John T. Hwang,Andrew Ning +1 more
TL;DR: This study applies adjointbased multidisciplinary design optimization to this highly coupled design problem, and a 12% increase in range is observed.
References
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Journal ArticleDOI
Computation of vortex sheet roll-up in the Trefftz plane
TL;DR: In this paper, the Cauchy principal value integral is desingularized to define the sheet's velocity, which converges with respect to refinement in the mesh-size and the smoothing parameter.
Journal ArticleDOI
Structure of trailing vortices.
BookDOI
High angle of attack aerodynamics : subsonic, transonic, and supersonic flows
TL;DR: In this paper, the authors present a presentation of the methods and results applicable to the study of the complex aerodynamics of a high angle of attack on the part of a fighter aircraft.
Journal ArticleDOI
High Angle-of-Attack Aerodynamics
TL;DR: High angle-of-attack (high-IX) aerodynamics has been a key element in airplane design beginning with the first attempts at unpowered manned flight using gliders in the 1 800s and extending to the present day with civil and military airplanes.