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Showing 1 to 18 of 18 for “"supersonic jets"”.
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Turbulence Statistics and Eddy Convection in Heated Supersonic Jets
Supersonic hot jet noise causes significant hearing impairment to the military workforce and results in substantial cost for medical care and treatment. Detailed insight into the turbulence structure of high-speed jets is central to understanding and controlling jet noise. For this purpose a new …
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Microjet based noise control of supersonic jets on carrier decks
… microjet control on the noise generated by a supersonic, ideally expanded, Mach 1.5, impinging jet was determined. Using a converging-diverging nozzle with a design Mach number of 1.5, the jet was operated at temperatures ranging from 60 to 1700°F. Six microjets were installed in the ground …
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Space-time Description of Supersonic Jets with Thermal Non-uniformity
The supersonic jet plumes that exhaust from the engines of tactical aircraft produce intense noise signatures that expose the Navy personnel working on the deck of aircraft carriers to dangerously high levels of noise that often results in hearing damage. Reducing the noise radiated by these …
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Reducing noise from supersonic jets using linear feedback control informed by resolvent analysis
Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2027-05-01
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Spatiotemporally-Resolved Velocimetry for the Study of Large-Scale Turbulence in Supersonic Jets
The noise emitted from tactical supersonic aircraft presents a dangerous risk of noise-induced hearing loss for personnel who work near these jets. Although jet noise has many interacting features, large-scale turbulent structures are believed to dominate the noise produced by heated supersonic …
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The Turbulence Structure of Heated Supersonic Jets with Offset Total Temperature Non-Uniformities
… to investigate the viability of reintroducing supersonic commercial transport in the United States and one of the largest problems to address is reducing the noise impact of these aircraft on communities. The overarching goal of jet noise research is to optimize noise reduction techniques for …
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Experimental investigation of noise reduction in supersonic jets due to jet rotation and to nozzle geometry changes
… different methods used for noise reduction in supersonic jets. The first method employed consisted of a swirl chamber, which produced axisymmetric jets with a tangential velocity component. This component was found to affect the structure of the jet cell and the internal oblique shocks formed …
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Theoretical and computational models of reacting silane gas flows : laser driven pyrolysis of subsonic and supersonic jets
Thesis (Sc.D.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1985.
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A Preliminary Study of Acoustic Prediction Technology Based on Detached Eddy Simulations for Supersonic Jets Impinging on Flat Plates
… of an existing industry tool to study supersonic jets impinging on at plates is shown. This industry tool is the commercially available CFD package ANSYS FLUENT. The supersonic jet studied is perfectly expanded with a Mach number of 1.5, and it impinges on a flat surface 4 nozzle throat …
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Stability, LES, and Resolvent Analysis of Thermally Non-uniform Supersonic Jet Noise
… investigates noise generation and dispersion in supersonic jets and focuses on the fluid-dynamic regime typical of high-performance turbojet and turbofan engines. The goal of my research is to understand how dispersion and propagation of wavepackets can be modified by noise reduction strategies …
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Spectroscopic signatures of isomnerization
… energy. The Ã-X̃ spectrum has been recorded in supersonic jets and molecular beams by laser induced fluorescence and H atom action detection, using double resonance techniques where appropriate to access and simplify portions of the Si manifold. Two major ab initio calculations have been …
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A Numerical Study of Supersonic Rectangular Jet Impingement and Applications to Cold Spray Technology
Particle-laden supersonic jets impinging on a flat surface are of interest to cold gas-dynamic spray technology. Solid particles are propelled to a high velocity through a convergent-divergent nozzle, and upon impact on a substrate surface, they undergo plastic deformation and adhere to the …
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Exploring fast package delivery from a systems perspective
… development with reusable launch vehicle and supersonic transportation technologies. However, a systems analysis of Fast Package Delivery has determined this market to be a difficult arena to enter. FPD has two modes of service. On one end is a mode for which the high transportation unit costs …
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Investigating the Interaction of a Supersonic Single Expansion Ramp Nozzle and Sonic Wall Jet
… up. The increase in velocities associated with supersonic jets, have exacerbated the need for flow physics research. Supersonic flight remains the standard for military aircraft and is being rediscovered for commercial use. With the addition of multiple streams, complex nozzle geometries, and …
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The Effect of Thermal Non-Uniformity on Coherent Structures in Supersonic Free Jets
Supersonic jet exhaust plumes produce noise in jet engines, which has been a problem in the aerospace field. Researchers are working on ways to reduce this turbulent mixing noise, with little modification to the engine and nozzle. Prior work has shown that total temperature non-uniformity is a …
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Measurements of Scalar Convection Velocity in Heated and Unheated High-Speed Jets
… of civilian complaints regarding the noise of jets near civilian and military air stations. One source of noise generation is from packets of air called eddies, which move with a convection velocity Uc. The current work seeks to expand upon the understanding of jet noise by collecting data …
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Numerical Simulation of Kraft Recovery Boiler Sootblower Jets
… that utilize boiler steam to generate supersonic steam jets that are literally used to knock deposits off of the boiler tubes. About 3 to 10\% of the total steam produced in a recovery boiler is used for sootblowing. This high energy cost demands that they be operated as efficiently as …
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Development of Specialized Laser Doppler Velocimeters for High Resolution Flow Profile and Turbulence Spectral Measurements
… motion and evolution of coherent structures in supersonic jet flows and how that relates to the intense noise the flows generate. As a preliminary study to experimentally address these relationships, novel non-intrusive measurements using two-component laser Doppler velocimetry (LDV) have been …