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 7 of 7 for “"Noise Control Devices"”.
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Design and development of advanced vibration and noise control devices using finite element analysis
The high sound pressure levels (SPL's) radiated inside the payload fairing by its vibrating frame causes 40% of the satellite damage in the initial phases of the launch. Numerous experiments conducted on the advanced vibration absorbers such as the distributed vibration absorbers (DVA's) and the …
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Modeling and validation of a syntactic foam lining for noise control devices for fluid power systems
Excessive fluid-borne noise in hydraulic systems is a problem the fluid power industry has long struggled to address. Traditional noise control devices such as Helmholtz resonators, tuning coils, and Herschel-Quincke tubes are generally too large for fluid power systems unless the speed of sound in …
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Aerodynamic Measurements in a Wind Tunnel on Scale Models of a 777 Main Landing Gear
… (VT-SWT) at a free-stream Mach number of 0.16. Noise control devices (NCD) were developed at Virginia Tech [9] to reduce noise by shielding gear components, reducing wake interactions and by streamlining the flow around certain landing gear components. Aerodynamic measurements were performed to …
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Numerical Study of Synthetic-Jet Actuation Effect on Airfoil Trailing Edge Noise
… Synthetic Jet Actuators (SJAs) as active noise control devices for reduction of airfoil acoustic radiation. High-accuracy numerical efforts employ a sixth-order accurate Navier-Strokes solver implementing a low-pass filtering of poorly resolved high-frequency solution content to retain …
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Passive Noise Control in Incubators
… Due to operating equipment and environmental noise, the sound level that is perceived by the developing newborn can cause both short and long term hearing loss as well as psychological damage [1].This thesis presents a study on how passive noise control devices can be used to reduce SPL levels …
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LORE Approach for Phased Array Measurements and Noise Control of Landing Gears
A novel concept in noise control devices for landing gears is presented. These devices consist of elastic membranes creating a fairing around the major noise sources. The purpose of these devices is to reduce wake interactions and to hide components from the flow, thus, reducing the noise emission. …
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Aeroacoustic Study of a Model-Scale Landing Gear in a Semi-Anechoic Wind Tunnel
… The VT Anechoic Stability Wind Tunnel allowed noise measurements to be carried out using both a 63-elements microphone phased array and a linear array of 15 microphones. The noise sources were identified from the flyover view under various flow speeds and the phased array positioned in both the …