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Showing 1 to 20 of 31 for “"vortex interaction"”.
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Turbulent flowfield downstream of a perpendicular airfoil--vortex interaction
… of an airfoil encountering an intense streamwise vortex. This type of perpendicular airfoil--vortex interaction commonly occurs in helicopter rotor flows. The experiments presented here thus provide useful information for the prediction of helicopter noise, particularly BWI noise. Three-component …
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Airfoil-vortex interaction and the wake of an oscillating airfoil
… investigate two-dimensional airfoil-vortex interaction. Vortices were generated by sinusoidally oscillating a NACA 0012 airfoil about its quarter-chord at a reduced frequency of k = 2.05 and an amplitude of ±10° angle of attack. The target airfoil, a NACA 63₂A015, was immersed in the …
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Predicting the high-frequency airloads and acoustics associated with blade-vortex interaction
As a rotorcraft descends or manoeuvres, the interactions which occur between the rotor blades and vortical structures within the rotor wake produce highly impulsive loads on the blades and with these a highly intrusive external noise. Brown’s Vorticity Transport Model has been used to investigate …
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Investigation of orthogonal blade-vortex interaction using a particle image velocimetry technique
… wake gives rise to the multitude of aerodynamic interactions that may occur during rotorcraft operation. These interactions may give rise to undesirable noise and lead to an unacceptable performance degradation, and as such the investigation of the fundamental mechanics of such interactions, that …
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A compressible, high frequency numerical model of helicopter noise due to blade/vortex interaction
Thesis: M.S., Massachusetts Institute of Technology, Department of Aeronautics and Astronautics, 1980
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Numerical simulation of wakes, blade-vortex interaction, flutter, and flutter suppression by feedback control
… This model is used to simulate wakes and blade-vortex interaction. This model is also coupled with dynamics and feedback controls to simulate flutter and flutter suppression. The flow is assumed to be attached and incompressible. The present aerodynamic model is based on a vorticity-panel method …
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An Experimental Investigation of Two-Dimensional Flame-Vortex Interactions (Acoustics Addition Rate)
Experiments have been performed to study the interaction between a flame and a single vortex impulsively generated by the flame. The objectives are to investigate the amplitude of the cylindrically diverging acoustic wave produced by the interaction and to develop a quantitative approach to …
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Large eddy simulation of subsonic mixing layers
… mixing layers, it is found that the streamwise vortex tubes play an important role in the transition process. The vortex interaction of the streamwise vortex tubes and undulated spanwise vortex structures proves to be the dominant mechanism in the development of three-dimensionality and the …
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Vortex driven flame dynamics and combustion instability
… elementary processes are acoustic wave-flame interactions, flame-vortex interactions, equivalence ratio fluctuations, flame-wall interactions and the unsteady stretch rate. To investigate the flame- vortex interaction mechanism, a parametric study is performed in single and double expansion …
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Strömungs- und Wärmeübergangsmessung für das zweistufige Raumtransportsystem ELAC
… crystal display technique. Three-dimensional vortex systems of the lower stage (single delta wing) and the orbital stage (double delta wing) are presented for high angles of attack. Shock/shock interaction of the bow shock of the orbital stage with the embedded shock of the lower stage as well …
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The source and evolution of turbulence in trailing vortex pairs
… 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 characteristics …
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Computational modelling of the vortex state in high-temperature superconductors
The vortex state in high temperature superconductors is investigated using computer simulations. Vortices are represented as particles and we employ Langevin dynamics to study the statics and dynamics of the system.<br/><br/>We show that the long-range nature of the vortex-vortex interaction can …
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Incident shock Mach number effects on Richtmyer-Meshkov mixing with simultaneous density and velocity measurements
… of Mach number variation, with differences in vortex interaction playing a critical role in the development of the flow field. Several quantities, including mixing layer width, mixing layer area, interface length, vorticity, circulation, velocity fluctuations, instantaneous mixing rate, the …
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Phase transitions and vortex dynamics in superconducting island arrays
… island arrays as a platform for studying vortex motion and quantum phase transitions. We investigate superconducting vortex dynamics and lattice structures in superconducting arrays by performing electrical transport measurements on Nb island arrays on Au at milli-kelvin temperatures and …
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An experimental and computational aerodynamic investigation of a low-canard high-wing aircraft design
… break have been attributed to the canard tip-vortex interaction with the main wing. Test Reynolds numbers were 260,000 for the first set and 300,000 for the second series of tests. Computational cases were run using both an uncambered vortex lattice method and a general three-dimensional …
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Aerodynamic interaction of an inverted wing with a rotating wheel
… to the knowledge on aerodynamic wing - wheel interaction. Hereto an experimental and computational study has been performed, during which the wing ride height and the wing - wheel overlap and gap have been considered as the primary variables. The wheel drag for the combined configuration is …
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Modification of Blade-Vortex Interactions Using Leading Edge Blowing
The interaction of an unsteady wake with a solid body can induce sizable loading of the structure, which has many detrimental side effects in both the structural and acoustic senses. These interactions are ubiquitous in nature and engineering. A flow control technique is sought to mitigate this …
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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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