Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 9 of 9 for “"Blade Vortex Interaction"”.
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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 …
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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
… of tip vortices from fixed wings and rotary blades. The numerical error is reduced by using high order accurate 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 …
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Numerical investigation of air vehicle noise propagation effects
… descent case experimental database is used. Blade Vortex Interaction (BVI) noise, the dominant noise contributor during descent, is mainly examined. It is shown that advancing side BVI noise is affected by nonlinear distortion, while retreating side BVI noise is not. For some frequency bands …
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Propeller Noise Prediction of an Urban Air Mobility Vehicle in Urban Environment
… unsteady aerodynamic environments where wake interactions, gust and turbulence significantly affect both performance and noise generation. Understanding these mechanisms is critical for developing quieter and more efficient eVTOL systems that meet future community noise and certification …
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Turbulence and Sound Generated by a Rotor Operating Near a Wall
… fed by jets of fluid that tend to form below the blade as it passes by the wall. Instantaneous velocity measurements show the presence of strong vortices in the tip gap. These vortices were characterized and found to be both stronger and more numerous on the downstroke side of the tip gap. …