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Showing 1 to 20 of 21 for “"shock propagation"”.
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Analysis of shock propagation in the magnetosheath
Four interplanetary shock waves and disturbances are analyzed. Data recorded by multiple spacecraft are compared in order to determine how the speed of these events is modified when they cross Earth's bow shock into the magnetosheath. To accomplish this, it was necessary to find shocks that were …
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Finite-strength shock propagation for alternative equations of state
… for finite-strength, i.e., nonself-similar, shock waves is developed. Using concepts of Lie groups, the invariance properties of the spherically symmetric equations of gasdynamics are determined and used to construct invariant equations of state. The invariant functions of this group are next …
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Application of an empirically-derived polytropic index for the solar wind to a solar wind shock propagation model
… into a magnetohydrodynamic model of solar wind propagation. This computer model is used to predict the time for shocks originating at the Sun to travel to Earth. This information is important for the protection of Earth-orbiting satellites. The model is a two and one-half-dimensional numerical …
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Spectroscopic observation of materials under dynamic conditions
… developed for direct real-time visualization of shock generation, propagation, and convergence in a sample. The approach opens up new possibilities for controlling the shock parameters and allows one to access pressures in the multiple gigapascal range. Optical generation of shock waves is …
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A hybrid parallel framework for computational solid mechanics
… problems, including a laser induced cylindrical shock propagation, a dynamic problem involving a micro-truss array made of millions of elements, and a tension problem involving a shape memory alloy with a multifield formulation to model the superelastic effect.
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Numerical Modeling of Friction Stir Welding: A Comparison of Alegra and Forge3
… process, in large part due to its focus on shock propagation, which causes extremely small time steps. Forge3 is shown capable of modeling of the FSW plunge process in a transient manner, but overestimates the temperature profiles 90% to 100% in comparison to experimentally measured values. …
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On the Need to Acquire Data for the Advancement of Shock Prediction
Today, most shock propagation predictions are empirically based, resulting from a single study done by Martin Marietta in 1970. That work examined a body of shock data available at the time to create empirically derived guidance on how shock magnitude propagates through joints and distance. Most …
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Shock convergence and mix dynamics in inertial confinement fusion
Understanding the phenomena of shock propagation and of turbulent mix induced by Rayleigh-Taylor (RT) instability growth is of critical importance for ignition and high gain in inertial confinement fusion (ICF). Capsule assembly and hot-spot formation require careful timing of multiple shocks to …
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Free-Lagrange simulations of single cavitation bubble collapse.
… code was developed. Simulations of conical shock waves for various geometries and axisymmetric shock propagation in a material incorporating strength were carried out for validation purposes. Here, the code, which employs second order space and first order time accurate Godunov-type solvers, …
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Modeling moderately dense to dilute multiphase reacting flows
… to use conventional stiff relaxation solvers. Shock propagation through a material interface, surface tension-driven oscillating droplet, droplet acceleration in a viscous medium, and shock/detonation interaction with a deforming droplet are simulated to validate various part of the …
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Particle simulation of laser-produced plasmas on the basis of analytic magnetohydrodynamic solutions
… applications include the study of magnetic shock propagation in conductors, laser-triggered fast switches, solid state physics in the highly nonlinear optical regime, pulse-shape detectors, compact high voltage ion accelerators, LDLC (Laser Driven Liner Compression), laser-driven propulsion, …
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Experimental and numerical study of the bleed effect on the propagation of strong plane and converging cylindrical shock waves
… to determine the effect of bleeding on the propagation of plane and converging cylindrical shock waves. A fully 3-D Finite Element code was written for simulating inviscid unsteady flow in various cases of shock tube geometry. The scheme used was implicit time-marching with the Galerkin …
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Materials At Extremes: Shock-induced Fracture and Phase Transitions
… high-pressures and strain-rates associated with shock waves, their study is of great interest to a host of different fields including, but not limited to, planetary sciences, medical applications, sports science, aerospace engineering, chemistry, and materials science. Most broadly, the study of …
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Three essays on financial economics
… are the individual abstracts. Chapter 1: Credit Shock Propagation in Firm Networks: Evidence from Government Bank Credit Expansions We study how bank credit shocks propagate through supplier-customer firm networks. We do so using administrative data that covers the near-universe of firm-to-firm …
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Development of mechano-active organic materials for shock wave energy dissipation
Materials capable of shock wave energy dissipation (SWED) are of interest for protecting personnel and machinery from explosions and ballistic impacts. Although current protective armors often prevent physical injuries by stopping shrapnel or bullets, the shock waves generated by explosions or …
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Heterogeneous agent models to determine spillover effects in the context of quantitative easing
… amplification effects occur in the event of a shock. For this purpose, we calibrate a model of fire-sale contagion to the South African banking sector. We use cross-sectional balance sheet data for 29 South African banking institutions. Fire-sale externalities are pecuniary externalities that …
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Bounded Rationality in Macroeconomics
… significant asymmetric, state-dependent shock propagation and stochastic volatility of output growth. The second chapter, “Strategic Mistakes” (jointly authored with Joel P. Flynn), more abstractly studies the equilibrium implications of state-dependent imperfections in optimization. We …
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Materials far from equilibrium : shock-induced deformation and chemistry in RDX and experimental development
… far-from-equilibrium dynamics that occur during shock waves cause irreversible material changes that are difficult to measure by conventional techniques. Measuring shocked materials requires techniques that can measure all of the relevant details (pressure, velocity, crystalline phase, etc.) in a …
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Multi-Fidelity Analysis and Optimization of Lightweight Structures Subject to Significant Fluid-Structure Interaction Effects
… while the internal fluid flow exhibits complex shock waves, reflections, and interactions. A three-stage solution strategy is proposed to capture the distinct physics and time scales of explosive burning, shock propagation, and the structural response to the FSI loading. The resulting framework …
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Hybrid shock dynamics models for heterogeneous explosives with embedded inert material
Made available in DSpace on 2016-03-02T20:24:08Z (GMT). No. of bitstreams: 3 LIEBERTHAL-DISSERTATION-2015.pdf: 17117421 bytes, checksum: cb0ad1c58510ca4b9b8e5a82e10486cc (MD5) Source Files.zip: 139575060 bytes, checksum: c8d25ed5b074095dc473e31bf00b8a2c (MD5) LICENSE.txt: 4215 bytes, checksum: …
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