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 10 of 10 for “"near-field pressure"”.
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Near-Field Pressure Distributions to Enhance Sound Transmission into Multi-Layer Materials
… of the resulting propagation angles, creating near-field pressure distributions in the solid material. By utilizing evanescent pressure distributions, which decay normal to the usual direction of propagation and are represented as plane waves propagating with complex angles, energy propagation …
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An Investigation of the Irrotational Near Field of an Excited High Speed Jet.
The near-field pressure of a Mach 0.9 jet with Reynolds number of 6.2x10^5 has been investigated to examine the response of the jet to low-frequency forcing with localized arc filament plasma actuators (LAFPAs). The well-defined actuation phase allows for the phase averaging of the near-field …
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Error Sensor Placement for Active Control of an Axial Cooling Fan
… noise control (ANC) for cooling fans have used near-field error sensors whose locations are determined according to a theoretical condition of minimized sound power. A theoretical point source model, based on the condition previously stated, reveals the location of near-field pressure nulls that …
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Error Sensor Strategies for Active Noise Control and Active Acoustic Equalization in a Free Field
… determine how to appropriately control a sound field. These include pressure, particle velocity, energy density and intensity. In this thesis, numerical models are used to show which signals perform best in is free-field active noise control (ANC) using error sensors located in the near field of …
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Performance analysis for lateral-line-inspired sensor arrays
… associated with such a sensor array, nearly nothing is known of the input processing and what information is available via the real lateral line. This thesis demonstrates and characterizes the ability of lateral-line-inspired linear pressure sensor arrays to perform two sensory tasks …
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Performance analysis for lateral-line-inspired sensor arrays
… associated with such a sensor array, nearly nothing is known of the input processing and what information is available via the real lateral line. This thesis demonstrates and characterizes the ability of lateral-line-inspired linear pressure sensor arrays to perform two sensory tasks …
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Mechanical counter-pressure space suit design using active materials
Mechanical counter-pressure (MCP) space suits have the potential to greatly improve the mobility of astronauts as they conduct planetary exploration activities; however, the underlying technologies required to provide uniform compression in an MCP garment at sucient pressures (29.6 kPa) for space …
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Crackle noise from high-speed free-shear-flow turbulence
… and intermittent character. The corresponding pressure fluctuations also have a peculiar shape with strong, steep compressions and weaker, rounded expansions, which is thought to be responsible, at least in some part, for their distinct perception. A complete explanation of this distinct and …
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Modern Methods in Machine Learning as Applied to the Study of a Complex Supersonic Jet Flow
… the past 80 years; however, the complex non-linear interactions between multiple merging canonical flows are not well understood. In this study, we seek to gain a better understanding of the flow physics in the near-field of a particular complex supersonic jet flow by using a combination of …
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Propeller Noise Prediction of an Urban Air Mobility Vehicle in Urban Environment
… to capture both unsteady flow dynamics and far-field sound radiation.</p> <p>The first part focuses on the investigation to transition (tilt) flight conditions, where both blade–vortex interaction (BVI) and blade–wake interaction (BWI) mechanisms are also dominant. This section explores the …