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Showing 1 to 19 of 19 for “"trailing vortex"”.
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Trailing vortex free-surface interaction
An investigation of the interaction of a trailing vortex with a free surface has been undertaken for the purpose of understanding the origin and scars and striations. Velocity and turbulence measurements have been carried out through the use of a Laser-Doppler-Velocimeter (LDV) for various …
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Wing trailing vortex paths in formation flight
… aircraft. This field is dominated by wing-tip trailing vortices. The paths of these vortices become too complex for rigid wake models downstream of the second aircraft in the formation. To tackle this problem, a combined vortex lattice and vortex filament numerical model was developed. For each …
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The turbulence structure of trailing vortex wakes
… of isolated vortices and counter-rotating vortex pairs. In the first part, the turbulence structure of an isolated vortex was studied using three-component velocity measurements. Vortices were generated using two symmetrical airfoils. Measurements were made in cross-sectional grids and …
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The structure of a trailing vortex wake
… performed in the spiral wake that surrounds the vortex shed from the tip of a rectangular NACA 0012 half wing. Both single-point and simultaneous two-point hot-wire measurements were made ten chord lengths downstream of the wing at a Reynolds number of 320,000. The structure of this flow consists …
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The source and evolution of turbulence in trailing vortex pairs
… from the experimental study of two different trailing vortex pairs has been conducted to obtain a more complete understanding of the turbulence structure of these flows. Statistical and spectral results, as well as filtered results and estimates of the effects of vortex wandering on the …
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A wind tunnel investigation of a wing-tip trailing vortex
… .2%. The tunnel was used to study a trailing vortex during its development at the wingtip and at 10 chordlengths downstream. The vortex was found to be well developed by 10 chordlengths. Helium bubble flow visualization was used to study the development of the vortex in the near-tip …
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High Resolution Simulation of Laminar and Transitional Flows in a Mixing Vessel
… investigation of the near-impeller flow and trailing vortex. Calculation and compilation of all terms in the turbulent kinetic energy transport equation was performed (including generation and the illusive turbulent pressure work). Specifically, the most important transport mechanism was …
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The effect of wing flexibility on ride comfort in formation flight
… an aerodynamic model, based on the classical Vortex Lattice Method (VLM) and structural and inertial models defined by stiffness and mass matrices. The VLM code was validated for both large aspect ratio wings with low frequencies in unsteady aerodynamic conditions, as well as swept wings in …
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Influence of aspect ratio on dynamic stall of a finite wing
… attributed to variations in the influence of the trailing vortex system on the dynamic stall behavior of the finite wings. Moreover, the computational results revealed that, for wings pitching at low angles of attack, a decrease in aspect ratio corresponds to a decrease in phase lag of the …
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Aerodynamic Properties of the Inboard Wing Concept
… tails, which may reduce the effect of the trailing vortex on trailing aircraft. During this investigation, two models of different scales were used to measure the aerodynamic forces and moments of the inboard wing configuration. The tests were conducted in the Virginia Tech 6X6 ft. wind …
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An experimental investigation of interacting wing-tip vortex pairs
The interactions of trailing vortex pairs shed from the tips of two rectangular wings have been studied through helium bubble flow visualizations and extensive hot wire velocity measurements made between 10 and 30 chord lengths downstream. The wings were placed tip to tip at equal and opposite …
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Time-Resolved PIV Measurements of Ship Airwakes with Quartering Winds
… quartering wind cases, the funnel wake had a trailing vortex on the windward side and large cross-sectional velocity magnitudes. The flight deck recirculation region decreased in size and became asymmetric for both quartering wind cases. Different flight deck vortical structures were found, …
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Towards a hybrid CFD platform for investigating aircraft trailing vortices
… area under consideration is modeling the trailing vortices shed from the wings of aircraft under transonic flight conditions. For this purpose, the Elemental® finite volume code is employed in the vicinity of the aircraft, while the Essense finite difference software is employed to …
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An improved panel method for the prediction of performance of ducted propellers
… of full wake alignment scheme in which the trailing vortex wake sheets of the blades are aligned with the local flow velocity by also considering the effects of duct and duct wake. A process of repaneling the duct is simultaneously introduced to improve the accuracy of evaluation of the …
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Towards Improvement of Numerical Accuracy for Unstructured Grid Flow Solver
… using a benchmark case about an inviscid vortex transporting in a free stream flow. In addition, the ability to capture the tip trailing vortex, which is a major challenge in computational fluid dynamics today, is extensively verified on two vortex dominated viscous flows, a fixed NACA0015 …
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Experimental Determination of Lift and Lift Distributions for Wings In Formation Flight
Experimental methods for the investigation of trailing vortex strengths, total lift, and lift distributions for three-dimensional wings in close proximity flight were developed. With these experiments we model compound aircraft flight either docked tip-to-tip, or flying in formation. There is a …
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Studies in Tip Vortex Formation, Evolution and Control
… schemes on appropriately refined meshes. For vortex evolution problems, the equations are solved on multiple {\em overset} grids that ensure adequate resolution in an efficient manner. For the RANS closure, a one equation wall-based turbulence model is used with a correction to the production …
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Numerical Investigation of the Wake of a Rectangular Wing
Wakes of lifting bodies contain vortex sheets that roll up into strong streamwise vortices. The long time behavior of such vortices depends on the turbulence in the wake and the stability characteristics of the vortices themselves. In the near wake of a rectangular wing the flow field consists of a …