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 20 of 36 for “"high-enthalpy"”.
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High-fidelity modeling of high-enthalpy plasma wind tunnels for hypersonic testing
Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2027-08-01
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A Study of Direct Measuring Skin Friction Gages for High Enthalpy Flow Applications
… gage for applications in three-dimensional, high-speed, high-enthalpy flows. Design conditions required favorable gage performance in the Arc-Heated Facilities at Arnold Engineering Development Center. Flow conditions are expected to be at Mach 3.4, with convective heat properties of h= 1,500 …
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Preliminary design of a high enthalpy plasma tunnel for atmospheric re-entry research
… the response of the material as it is exposed to high reactive, high-temperature flow. The data collected from the experiments conducted at the facility will be used to verify computer models as well as material performance characteristics. This thesis describes the preliminary design process and …
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Skin Friction Sensor Design Methodology and Validation for High-Speed, High-Enthalpy Flow Applications
… sensor capable of performing favorably in high-speed, high-enthalpy flow conditions, such as that found in atmospheric re-entry vehicles, scramjets, jet engines, material testing, and industrial processes. Fully understanding and optimizing these complex flows requires an understanding of …
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Modeling of high enthalpy flows for hypersonic re-entry and ground-based arc-jet testing
… presents a simulation framework for modeling high enthalpy ionized gas flows during planetary entry flights and ground-based arc-jet testing. The system of Favre-averaged Navier-Stokes equations in thermo-chemical non-equilibrium with Spalart-Allmaras turbulence closure is outlined, along with …
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Prediction of flight measurements of high enthalpy nonequilibrium flow from a cubesat-class atmospheric probe
Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2018-08-31 without embargo terms
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Development and Ground Testing of Direct Measuring Skin Friction Gages for High Enthalpy Supersonic Flight Tests
… skin friction gages were developed for a high-speed, high-temperature environment of the turbulent boundary layer in flows such as that in supersonic combustion ramjet (scramjet) engines, with a progression from free-jet ground tests to a design for an actual hypersonic scramjet-integrated …
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An actively cooled floating element skin friction balance for direct measurement in high enthalpy supersonic flows
… AMES Research Center. Flow conditions in the high enthalpy combustor models ranged from total pressures of 275-800 psia (1900-5550 kPa) and total temperatures from 5800-8400 R (3222-4667 K). This gives enthalpies in the range of 1700-3300 BTU/Ib<sub>m</sub> (3950-7660 KJ/kg) and simulated …
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Post-shock thermochemistry in hypervelocity CO2 and air flow
This work represents ongoing efforts to study high-enthalpy carbon dioxide flows in anticipation of the upcoming Mars Science Laboratory (MSL) and future missions to the red planet. The work is motivated by observed anomalies between experimental and numerical studies in hypervelocity impulse …
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Retrograde melting in transition metal-silicon systems : thermodynamic modeling, experimental verification, and potential application
… at temperatures above the binary eutectic. High enthalpy of formation of point defects in silicon leads to retrograde solubility for a number of solutes, including many 3d transition metals. The Ni-Si system is used to demonstrate that in silicon under supersaturated conditions, such solutes …
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Experimental study of heat transfer to hypersonic nozzle walls
The heat transfer rate from a high enthalpy gas to the walls of a diverging nozzle, through which the gas was flowing, has been experimentally determined. The experimental results are compared with the predictions of several theories for the heat transfer through a laminar boundary layer from a …
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Design, construction and characterization of a wind tunnel
… wind tunnels. The progress of the wind tunnel is highly related to the advancements in air crafts. Aircraft manufacturing has pushed the wind tunnel technology forward. Wind tunnels can be categorized by the wind speed limit differences, which are controlled by the mechanism of the driving …
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Flameholding methods for compact hypersonic systems
… hypersonic systems were characterized using high-speed pressure measurements and imaging in the high-enthalpy supersonic facility ACT-II. “Hypermixer” geometries consisting of tapered wedges with and without expansion-ramp vortex generators were tested in an axisymmetric Mach 2.6 flowpath to …
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Validation of Conjugate Heat-Transfer Capability for Water- Cooled High-Speed Flows
… are validated against existing data for three high speed water-cooled wind tunnel experiments: i) Air Force high-enthalpy nozzle test which recorded the increase in water coolant temperature, ii) Jet Propulsion Lab converging-diverging nozzle test for which nozzle and run-up were …
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Laser absorption spectroscopy for investigation of hypersonic propulsion
… of the hypersonic flight environment. Generating high enthalpy conditions often produces a test gas with an altered chemical composition, which can influence combustion performance downstream. This dissertation first addresses this issue by characterizing the inflow gas in the ACT-II facility, …
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Optimization of enhancements to aluminum-based structural energetic materials
… most often made of steel due to its low cost, high strength, good manufacturability, and ability to produce dense high-speed fragments. However, inert steel does not improve blast wave characteristics. In fact, it significantly reduces peak blast pressure and impulse as energy is expended in …
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Conceptual design of nuclear systems for hydrogen production
… reactor for providing heat and electricity for high temperature steam electrolysis and a hybrid electrolysis-chemical sulfur cycle. Also addressed is the sensitivity of production and efficiency of these cycles to process conditions. For a desired hydrogen distribution pressure of 3MPa, high …
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Application of Ab-initio Quantum Chemistry Techniques to Hypersonic Flows for Plasma Blackout Alleviation
… blocks communications with vehicles flying in a high-enthalpy flow environment. The ability to mitigate this issue can be useful from various re-entry vehicles to in-atmosphere hypersonic vehicles, especially with aerospace largely pushing into the hypersonic field across the industry. This …
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Design of Gages for Direct Skin Friction Measurements in Complex Turbulent Flows with Shock Impingement Compensation
… disparate test conditions: 1) short-duration, high-enthalpy testing, 2) blow-down testing, and 3) flight testing. The resulting optimized gage designs were virtually tested against each set of nominal load conditions. The finalized designs each successfully met their respective test condition …
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Floating head skin friction gage measurements in supersonic flows
… the skin friction coefficient in short duration, high enthalpy supersonic flows as well as long duration supersonic flows. The Macor model design yielded skin friction coefficient values near the expected value of 0.0014 when placed in a supersonic tunnel at both Mach 2.4 and Mach 3.0 and in a …
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