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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 42 for “"hypervelocity"”.
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Optimal trajectories for hypervelocity flight
This thesis discusses optimal trajectories for hypervelocity flight of interest in aeroassisted orbital transfer. Both coplanar orbital transfer and noncoplanar orbital transfer are studied. For these cases, the GEO-to-LEO transfer, the HEO-to-LEO transfer, and the LEO-to-LEO transfer are …
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Crater Size in Hypervelocity Impact
Made available in DSpace on 2014-12-09T17:13:41Z (GMT). No. of bitstreams: 1 6711920.pdf: 2541868 bytes, checksum: 7339d3c77948342359b2580ea42841b6 (MD5) Previous issue date: 1967
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Investigations of Hypervelocity Impact Physics
… at relative velocities exceeding 10 km/s. Such hypervelocity impacts (HVI) create immense shock pressures and can melt or vaporize aerospace materials, even inducing brief plasmas at higher speeds. Sacrificial shields have been developed to protect critical components from damage under these …
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Graphene Nano-Composites For Hypervelocity Impact Applications
… provided good potential for enhancement of the hypervelocity impact (HVI) shield resistance. The nano-composites are suggested for use as a coating. Moreover, explicit dynamic finite element studies were conducted for further investigation of the hypervelocity impact of the graphene-based …
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Machine Learning Methods for Hypervelocity Fragment Flyout Characterization
… events, such as collisions and explosions, hypervelocity fragments create potential hazards for both terrestrial and on-orbit environments, such as terrestrial weapons explosions and satellite breakup events, respectively. To avoid unnecessary damage, an accurate understanding or …
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Experimental surface heat flux measurement in hypervelocity flows
… of variations in geometry on heat transfer. The Hypervelocity Expansion Tube (HET) is one of a few facilities in the US that are able to create these flows, and thus it is an optimal test bed for these types of studies. Two gage types used in order to measure surface heat transfer, thermocouples …
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Post-shock thermochemistry in hypervelocity CO2 and air flow
… between experimental and numerical studies in hypervelocity impulse facilities for high enthalpy carbon dioxide flows. In this work, experiments are conducted in the Hypervelocity Expansion Tube (HET) which, by virtue of its flow acceleration process, exhibits minimal freestream dissociation in …
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Post-Shock Thermochemistry in Hypervelocity Carbon Dioxide and Air Flow
… region behind a stationary shock wave in a hypervelocity air Mach 7.42 freestream. The normal shock wave is established through a Mach reflection from an opposing wedge arrangement. Schlieren images confirm that the shock configuration is steady and the location is repeatable. Emission …
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Hypervelocity impacts and the evolution of planetary surfaces and interiors
The thesis consists of five studies relating impact processes to the evolution of planetary interiors as well as impact structures on planetary surfaces. Chapter 2 is concerned with developing methods for estimating the amount of heat deposited deep in terrestrial mantles by large impacts. Chapter …
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Multiphysics Model of Hypervelocity Impact and Impact Induced Plasma Formation
Previous studies on hypervelocity impact (HVI) have primarily focused on the mechanical response of solids, namely the projectile and the target. While several experiments have observed plasma formation and associated electromagnetic (EM) emissions, key questions remain unresolved — including the …
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Hypervelocity Impact Analysis of Hybrid Nanocomposite Sensors for Inflatable Space Structures
… Monte Carlo simulations from past research. A hypervelocity impact test was designed and executed at the University of Dayton Research Institute, Ohio, to test the response of the sensors to hypervelocity impacts. Aluminum spheres of 3 mm diameter and 4.5 mm diameter were accelerated to 7 km/s …
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Effects of local and global mechanical distortions to hypervelocity boundary layers
Made available in DSpace on 2014-01-16T17:56:47Z (GMT). No. of bitstreams: 2 William_Flaherty.pdf: 14269869 bytes, checksum: ddea397858017d2c8060ef6dfdb0d284 (MD5) license.txt: 4066 bytes, checksum: be9efb1fd923c4e0e534075ef6729386 (MD5)
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Statistical study of rock drilling by hypervelocity jets from explosive shaped charges
<p>"The drilling effect in rock of hypervelocity jets from explosive shaped charges was investigated experimentally to supplement a rapid excavation concept. The effects of the design factors of the charge and the mechanical properties of eight rock types were studied. Experiments were both …
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Experimental observations of aluminum particle combustion during hypervelocity water impact and penetration
Experiments conducted at the University of Illinois Urbana-Champaign have investigated the reaction between Al shaped charge jets and underwater environments. Although many qualitative and semi-quantitative characteristics are known, including pressure field augmentation, light emission from …
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Numerical study of projectile shape effect on the bumper performance under hypervelocity impact
… software ANSYS Autodyn to simulate the hypervelocity impact at 7km/s of differently shaped projectiles on to an all-aluminum bumper and rear-wall configuration. The craters produced by the debris cloud of spheres and cylinders of various geometries were compared and used to establish …
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Surface mapping based on the correlated emission of ions and electrons from hypervelocity C60 impacts
High resolution mapping of molecular species, specifically sub-micrometer spatial resolution mapping, is at the forefront of recent interest in Secondary Ion Mass Spectrometry (SIMS). Large projectiles, e.g. C60, Au400, display high quasi-molecular ion yields with reduced fragment ion yields …
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Further experimental investigations of underwater reactive shaped charge liners and aluminum particle combustion during hypervelocity water impact and penetration
The overall motivation of this project was to continue the investigation of reactive shaped charges. Although significant chemical energy is available in the form of combustion, the coupling of this energy to the target depends critically on the rate and position of energy deposition. Since this …
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Fast Stars in the Milky Way
… The stars escaping the Milky Way are termed hypervelocity stars. In Ch. 4, I overturn the consensus that the hypervelocity stars originated in the Galactic centre by showing that a Large Magellanic Cloud (LMC) origin better explains their distribution on the sky. In Ch. 5 I present three …
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Exploration of a superposition and reconciliation based approach to cell-centered Lagrangian hydrodynamic methods
Applications and experiments involving the hypervelocity deformation of solids are difficult to devise, implement, and occur on microsecond time scales. As a result, simulations play a large role in the study of hypervelocity deformation. This study explored a superposition and reconciliation based …
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