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Dissertations / Theses on the topic 'Shock waves'

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Published: 4 June 2021

Last updated: 29 July 2024

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1

Sen, Srimoyee, and Naoki Yamamoto. "Chiral Shock Waves." AMER PHYSICAL SOC, 2017. http://hdl.handle.net/10150/624056.

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We study the shock waves in relativistic chiral matter. We argue that the conventional Rankine-Hugoinot relations are modified due to the presence of chiral transport phenomena. We show that the entropy discontinuity in a weak shock wave is quadratic in the pressure discontinuity when the effect of chiral transport becomes sufficiently large. We also show that rarefaction shock waves, which do not exist in usual nonchiral fluids, can appear in chiral matter. The direction of shock wave propagation is found to be completely determined by the direction of the vorticity and the chirality of fermions. These features are exemplified by shock propagation in dense neutrino matter in the hydrodynamic regime.

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2

Molder, Sannu. "Curved aerodynamic shock waves." Thesis, McGill University, 2012. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=110629.

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1AbstractCurved shock theory (CST) has been extended to apply to axisymmetric shocks in non-uniform flow. A general formula has been derived for the vorticity jump across a doubly curved shock in non-uniform flow. Influence coefficient forms of equations for the gradients and vorticity show the effect of changing pre-shock conditions. CST has been applied to a series of simple shock flows and to the orientation of the sonic surface at the rear face of a doubly curved shock. This orientation is significant in determining the occurrence of embedded shocks in the post-shock flow. Application of CST to curved, concave, normal shocks allowed the derivation of an explicit relationship between the shock's curvature and the length of down-shock subsonic flow. Investigations of conical flows by analysis, CFD and experiment all failed to demonstrate the existence of regular reflection of shocks at the centre line of axisymmetric flows. An analytically predicted conical shock, on the calculated streamline, does not extend all the way to the centre line but terminates in Mach reflection. It appears that the existence of an analytical Taylor-Mccoll (T-M) solution is not in itself a guarantee of the physical existence of a conical flow in all cases. The T-M equations predict the existence of an axisymmetric centered compression fan, analogous to the Prandtl-Meyer fan in planar flow. A free-standing conical shock is located downstream of the compression fan. Both features have been shown to exist by CFD as well as experiment. Busemann flow is the only flow where these wave structures can exist; it is possible to reflect an incident, centered compression as a conical shock. Discovery of an inflection point on the Busemann streamline has an important implication to spontaneous starting of Busemann intakes. Three types of flow can exist behind a doubly curved concave shock; characterized by the orientation of the sonic surface which, in turn, is determined by the pre-shock Mach number and the shock curvatures ratio. Shapes of special axial shock surfaces, with straight post shock streamlines (Crocco shocks), or vanishing streamwise pressure gradient (Thomas shocks) and shocks with specific sound reflectivity (zero, if desired), have been calculated and illustrated. Boundary layer generated noise abatement is a possibility. Local flow choking, near the leading edge, leads to shock detachment from a curved wedge with such detachment depending on freestream Mach number, the wedge2angle, the wedge curvature and the wedge length. These are new criteria for shock detachment with analogies extending to the transition from regular to Mach reflection of shock waves.
1RésuméLa théorie des ondes de chocs courbées (TOCC; Curved Shock Theory) a été généralisée aux chocs axisymétriques dans un écoulement non uniforme. Une formule générale a été dérivée pour les sauts de vorticité à travers un choc à double courbe dans un écoulement non uniforme. La forme coefficient d'influence des équations des gradients et de la vorticité démontrent l'effet de la variation des conditions en amont. La TOCC a été appliquée à plusieurs écoulements simples avec chocs incluant l'orientation de la surface sonique à la face arrière d'un choc à double courbe. Cette orientation est importante pour déterminer l'existence d'ondes de choc intégrées à l'écoulement aval. L'application de la TOCC aux ondes de choc courbées, concaves et normales permet de dériver une relation explicite entre la courbe du choc et la longueur de l'écoulement subsonique derrière l'onde. L'étude analytique, numérique et expérimentale des écoulements coniques n'a pas permis de démontrer l'existence de réflexions régulières des chocs à l'axe de symétrie des écoulements. Un choc conique prédit analytiquement sur la ligne d'écoulement n'atteint pas l'axe central, mais se termine en réflexion Mach. Il semble que l'existence d'une solution Taylor-Mccoll (T-M) ne garantit pas l'existence physique d'un écoulement conique. Les équations T-M prédisent l'existence d'un train d'ondes de compression axisymétrique, analogue au train d'ondes de Prandtl-Meyer dans un écoulement planaire. Un choc conique détaché est situé en aval du train de compression. L'existence des deux caractéristiques a été démontrée par CFD ainsi qu'expérimentalement. L'écoulement Busemann est le seul écoulement où ces structures d'ondes peuvent exister : une compression centrée peut être reflétée en onde de choc conique. La découverte d'un point d'inflexion dans la ligne d'écoulement de Busemann a une implication importante au démarrage spontané de diffuseurs Busemann. Trois types d'écoulements peuvent exister à l'arrière d'un choc concave à double courbure : ils sont caractérisés par l'orientation de la surface sonique qui, à son tour, est déterminée par le nombre de Mach pré-choc et le ratio de courbures du choc. Des formes de surfaces d'ondes de choc axiales particulières, avec écoulement droit en aval (chocs Crocco), ou avec un gradient de pression tendant vers zéro dans l'axe d'écoulement (chocs Thomas) ainsi que des chocs avec une réflectivité acoustique spécifique (incluant nulle) ont été calculées et illustrées. Une réduction du bruit de couche limite est aussi possible.2L'étranglement local au bord d'attaque d'une pointe courbée mène au détachement de l'onde de choc, lequel dépend du nombre de Mach de l'écoulement libre, de l'angle, de la courbure et de la longueur de la pointe. Ce sont de nouveaux critères pour le détachement du choc avec des analogies pouvant s'étendre aux transitions des réflexions régulières aux réflexions Mach.

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3

Eliasson, Veronica. "On focusing of shock waves." Doctoral thesis, Stockholm : Mekanik, Kungliga Tekniska högskolan, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4479.

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4

Barker, Bryn Nicole. "Stability of MHD Shock Waves." BYU ScholarsArchive, 2020. https://scholarsarchive.byu.edu/etd/8437.

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This thesis focuses on the study of spectral stability of planar shock waves in 2-dimensional magnetohydrodynamics. We begin with a numerical approach, computing the Lopatinski determinant and Evans function with the goal of determining if there are parameters for which viscous waves are unstable and the corresponding inviscid waves are stable. We also begin developing a method to obtain an explicit, analytical representation of the Evans function. We demonstrate the capabilities of this method with compressible Navier-Stokes and extend our results to 2-D MHD. Finally, using compressible Navier-Stokes again, we derive an energy estimate as a first step in improving the bound on possible roots of the Evans function.

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5

Fu, Y. "Propagation of weak shock waves in nonlinear solids." Thesis, University of East Anglia, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.384589.

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6

Eliasson, Veronica. "On focusing of strong shock waves." Licentiate thesis, Stockholm : Department of Mechanics, Royal Institute of Technology, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-565.

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7

Owen, Neil R. "Targeting of stones and identification of stone fragmentation in shock wave lithotripsy /." Thesis, Connect to this title online; UW restricted, 2007. http://hdl.handle.net/1773/5895.

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8

Carter, John P. "Magnetic field generation in shock waves." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1994. http://edocs.nps.edu/npspubs/scholarly/theses/1994/June/94Jun_Carter.pdf.

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9

Waterman, Alfred James. "Laser-driven shock waves in quartz." Thesis, University of British Columbia, 1990. http://hdl.handle.net/2429/28728.

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The formation and propagation of laser-driven shock waves has been observed by optical shadowgraphy in fused quartz, α-quartz and sodium chloride. Target materials were irradiated with a 0.53 µm , ~ 2.5 ns FWHM laser pulse at intensities ranging between 0.2 — 2 x 10¹³ W/cm², producing peak pressures varying from 0.3 — 3 Mbar at the shock front. Observations in both varieties of quartz reveal transient, high-speed shock propagation followed by deceleration towards a steady asymptotic shock speed. Similar high-speed transients were not seen in sodium chloride. The results in quartz were found to be in significant disagreement with both one-dimensional and two-dimensional hydrodynamic calculations based on equilibrium equations of state. The non-steady shock propagation is interpreted as being due to a relaxation process in the phase transformation of quartz into the high-pressure stishovite phase which occurs at the shock front. The effects of such a relaxation process on the shock dynamics and shock compression process are considered for the case of a direct relaxation from quartz into stishovite, as well as for an indirect relaxation process in which the -transformation of quartz into stishovite is preceded by shock-induced amorphization of the quartz. It is shown that either scenario would result in higher shock speeds and less compressible shock states than those obtained under equilibrium conditions.
Science, Faculty of
Physics and Astronomy, Department of
Graduate

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10

Miyahara, Seiji, Takahiro Kawashima, and Yukiharu Ohsawa. "Field strengths in oblique shock waves." American Institute of Physics, 2003. http://hdl.handle.net/2237/7022.

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11

Wang, Yi-Chun Brennen Christopher E. "Shock waves in bubbly cavitating flows /." Diss., Pasadena, Calif. : California Institute of Technology, 1996. http://resolver.caltech.edu/CaltechETD:etd-02282006-144334.

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12

Nymark, Tanja. "X-ray emission from supernova shock waves." Doctoral thesis, Stockholm : Department of Astronomy, Stockholm university, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-6671.

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13

Harries, Nicholas. "Probing supernova shock waves via neutrino oscillations." Thesis, University of Oxford, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.490069.

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The time dependent neutrino oscillation signals due to the passage of a shock wave through the supernovae are analyzed for the case of three active neutrinos and also for the case that there are two additional sterile neutrinos. I re-examine the Landau-Zenner formula, which gives the level crossing probability at a MSW resonance, probing the deviations with specific application to the supernova shock wave. I use these results to examine phase effects which could be present due to multiple resonance crossings at the forward and reverse shocks.

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14

Svedholm, Matheus, and Josefine Gessl. "Laboratory exercise - Compressible flow, oblique shock waves." Thesis, KTH, Skolan för teknikvetenskap (SCI), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-276595.

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When studying to become an engineer the education is mainly theoretical and to confirm the theory laboratory exercises are incorporated in the curriculum. Being able to visualize the phenomenons studied helps in giving the students a deeper understanding. The purpose of this report is to aid the department of fluid mechanics at KTH in designing an experiment to help the students understand the theory of oblique shock waves. The project is divided in two parts. Part one the design of the wedge and base plate and part two the creation of the actual experiment and lab PM. The design of the wedge is quite simple. It is a sharp wedge with two angles measured from the horizontal plane, 8° at the top and 4° at the bottom, this is so that two measurements can be made per experiment. Writing the PM and the design of the exercise is the main part of this project. The result is a laboratory exercise where the students compare the flow around a wedge in a shock tube for three different Mach numbers, subsonic, transonic and supersonic. Using shadowgraph optics and a high speed camera the image of the shock is captured. The different regimes are then discussed and compared with the help of theoretical calculations and the measured values.
Inom ingenjörsutbildningar är utbildningen huvudsakligen teoretisk och för att bekräfta teorin integreras laborationer i läroplanen. Möjligheten att visualisera de studerade fenomenen hjälper studenterna att få en djupare förståelse. Syftet med denna rapport är att hjälpa den strömningsmekaniska avdelningen på KTH att ta fram ett experiment som hjälper studenterna att förstå teorin om sneda stötvågor. Projektet är uppdelat i två delar. Del ett, design av kilen och fästet och del två framtagningen av själva experimentet och lab PMet. Kilens design är ganska simpel. Det är en vass kil med två vinklar mätta från horisontalplanet , 8° på ovansidan och 4° på undersidan, detta så att man kan göra två mätningar per experiment. Utformandet av laborationen och labpeket är huvuddelen av detta projekt. Resultatet är en laboration där studenterna jämför flödet runt en kil i ett stötrör för tre olika machtal, subsoniskt, transoniskt och supersoniskt. Med hjälp av en höghastighetskamera och shadowgraph optik kan stötvågen fångas på bild. De olika scenarierna diskuteras och jämförs med hjälp av teoretiska beräkningar och de uppmätta värdena.

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15

Bhat, Harish Subrahmanya Marsden Jerrold E. "Lagrangian averaging, nonlinear waves, and shock capturing /." Diss., Pasadena, Calif. : California Institute of Technology, 2005. http://resolver.caltech.edu/CaltechETD:etd-05262005-100534.

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16

Riveiro, Moreno Carmen. "Interaction of shock waves with compliant walls." Electronic Thesis or Diss., Institut polytechnique de Paris, 2024. http://www.theses.fr/2024IPPAX011.

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Cette thèse vise à caractériser l'interaction entre une paroi souple et un choc normal transsonique. La topologie et la dynamique de l'écoulement sur une paroi rigide sont d'abord déterminées. En utilisant visualisations strioscopiques et des mesures de pression instationnaires, les différentes échelles temporelles et de longueur impliquées dans l'interaction entre l'onde de choc et la couche limite turbulente sont caractérisées.Une paroi souple est ensuite conçue de manière à ce que ses fréquences naturelles se situent dans le même ordre de grandeur que la gamme de fréquences des oscillations des ondes de choc. De cette manière, la paroi retenue pour l'étude est censée réagir au forçage de l'onde de choc. Le matériau et la géométrie de la paroi souple sont déterminés par des études numériques paramétriques basées sur l'analyse modale ainsi que sur la déformation statique de la paroi souple causée par l'écoulement. Deux parois conformes sont fabriquées, l'une présentant un comportement élastique et l'autre un comportement viscoélastique.L'interaction entre l'onde de choc normale et les parois conformes est caractérisée expérimentalement. Dans les deux cas, plusieurs positions de choc dans la veine d'essais sont étudiées. Dans la configuration de la paroi souple élastique, l'interaction fluide-structure dépend fortement de la position du choc. L'interaction fluide-structure varie d'un régime synchrone de grande amplitude à un régime non synchronisé, en fonction de la position du choc. Le régime synchrone à grande amplitude a été étudié en fonction des fréquences naturelles de la structure. À cette fin, l'épaisseur de la paroi souple et les conditions aux limites ont été modifiées. L'amplitude des oscillations diminue considérablement avec l'augmentation de l'épaisseur. La fixation de la surface inférieure de la paroi élastique n'entraîne aucune interaction fluide-structure. Dans la configuration de la paroi souple viscoélastique, on observe de grandes déformations de la paroi souple sans interaction dynamique fluide-structure. Ce résultat met en évidence la capacité des matériaux viscoélastiques à réagir différemment en fonction de la fréquence du forçage externe : la grande déformation statique de la paroi souple correspond à une structure souple, tandis que sa réponse dynamique est caractéristique d'une structure rigide
This thesis aims to characterize the interaction between a compliant wall and a transonic normal shock. The flow topology and dynamics over a rigid wall is first determined. Using schlieren visualisation and unsteady pressure measurements the different temporal and length scales involved in the shock wave turbulent boundary layer interaction are characterized.A compliant wall is then designed so that its natural frequencies are within the same order of magnitude as the frequency range of the shock oscillations. In that manner, the compliant wall is expected to react to the shock wave forcing. The compliant wall's material and geometry are determined through numerical parametric studies based on modal analysis as well as the static deformation of the compliant wall caused by the flow. Two compliant walls are manufactured, one exhibiting elastic behavior, and the other viscoelastic behavior.The interaction between the normal shock wave and the compliant walls are experimentally characterized. In both cases the shock location is varied. In the elastic compliant wall configuration, the fluid-structure interaction is highly dependent on the shock position. The fluid-structure interaction varies from a large-amplitude synchronized regime to a non-synchronized regime, depending on the shock position. The large-amplitude synchronized regime was studied as a function of the structural natural frequencies. For that purpose, the compliant wall thickness and boundary conditions were modified. With increasing thickness, the amplitude of the oscillations considerably diminishes. Clamping the bottom surface of the elastic compliant wall yields no fluid-structure interaction. On the viscoelastic compliant wall configuration, large deformations of the compliant wall with no dynamic fluid-structure interaction are found. Such a result highlights the capability of viscoelastic materials to react differently depending on the external forcing frequency: the compliant wall's large static deformation corresponds to a soft structure, whereas its dynamic response is characteristic of a rigid one

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17

Vandersall, Kevin S. "Investigation of shock-induced and shock-assisted chemical reactions in Mo-Si powder mixtures." Diss., Georgia Institute of Technology, 1999. http://hdl.handle.net/1853/19146.

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18

Faletic, Rado, and Rado Faletic@anu edu au. "Tomographic reconstruction of shock layer flows." The Australian National University. Faculty of Science, 2005. http://thesis.anu.edu.au./public/adt-ANU20050727.121303.

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The tomographic reconstruction of hypersonic flows faces two challenges. Firstly, techniques used in the past, such as the Direct Fourier Method (DFM) or various backprojection techniques, have only been able to reconstruct areas of the flow which are upstream of any opaque objects, such as a model. Secondly, shock waves create sharp discontinuities in flow properties, which can be difficult to reconstruct both in position and in magnitude. This thesis will present a reconstruction method, utilising geometric ray-tracing and a sparse matrix iterative solver, which is capable of overcoming both of these challenges. It will be shown, through testing with phantom objects described in imaging and tomographic literature, that the results are comparable to those produced by the DFM technique. Finally, the method will be used to reconstruct three dimensional density fields from interferometric shock tunnel images, with good resolution.

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19

Kjellander, Malte. "Energy concentration by converging shock waves in gases." Doctoral thesis, KTH, Mekanik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-95186.

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Converging shock waves have been studied experimentally in a shock tube, and numerically using inviscid calculations and the theory of geometrical shock dynamics. The converging shock waves were created in a shocktube with two modular test sections designed to create cylindrical respectively spherical waves. In the spherical case the shock waves take the shape of spherical cap before propagating into a cone, while the cylindrical shocks converge in a fully circular cylindrical chamber. The dynamics and symmetry of circular and polygonal cylindrical shock waves with initial Mach numbers ranging from 2 to 4 were studied. The shocked gas at the centre of convergence attains temperatures high enough to emit radiation which is visible to the human eye. The strength and duration of the light pulse due to shock implosion depends on the medium. In this study, shock waves converging in air, argon, nitrogen and propane have been studied. Circular shock waves are very sensitive to disturbances which deform the shock front, decreasing repeatability. Shocks consisting of plane sides making up a symmetrical polygon have a more stable behaviour during focusing, which provides less run-to-run variance in light strength. The radiation from the gas at the implosion centre has been studied photometrically and spectrometrically. The full visible spectrum of the light pulse created by a shock wave in argon has been recorded, showing the gas behaving as a blackbody radiator with apparent temperatures up to 6,000 K. This value is interpreted as a modest estimation of the temperatures actually achieved at the centre as the light has been collected from an area larger than the bright gas core. Circular shock waves attained higher temperatures but the run-to-run variation was significant. The propagation of circular and polygonal shocks was also studied using schlieren photography and compared to the self-similar theory and geometrical shock dynamics, showing good agreement. Real gas effects must be taken into consideration for calculations at the implosion focal point. Ideal gas numerical and analytical solutions show temperatures and pressures approaching infinity, which is clearly not physical. Real gas effects due to ionisation of the argon atoms have been considered in the numerical work and its effect on the temperature has been calculated. A second convergent test section was manufactured, designed to smoothly transform a plane shock wave into the shape of a spherical cap. After the convergent transformation the spherical shock propagates through a conical section, where it is aimed to retain the spherical shape and converge in the tip of the truncated cone, which has an end radius of 0.3 mm. Spherical implosion is more efficient than cylindrical and the target volume is much smaller than that in the cylindrical chamber. The new set-up does not suffer from large losses through reflections. Spectrometric and photometrical measurements of the implosion show significantly stronger radiation of longer duration. Preliminary results show measured apparent blackbody temperatures up to 27,000 K during implosion of shock waves of initial Mach number MS = 3.9.
QC 20120521

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20

Arshed, Ghulam Murshed. "Numerical method for compressible turbulence with shock waves." Wichita State University, 2012. http://hdl.handle.net/10057/5517.

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This dissertation proposes improvements in the numerical algorithm for the dynamics of flows that involve discontinuities and broadband fluctuations simultaneously. These two flow features suggest numerical strategies of a paradoxical nature because the discontinuities demand large dissipation and the small-scale smooth features require the opposite. There may be several ways to approach such a complicated issue, such as combining a shock-capturing scheme with a low dissipative method using a shock detector, but the natural choice, to avoid the redundancy of using the shock detector and the stability issue as a result of coupling, is a numerical technique that can adjust adaptively with flow regimes. The weighted essentially non-oscillatory (WENO) scheme may be this choice. However, there are two sources of dissipation associated with the WENO procedure: upwind optimal stencil and nonlinear adaption mechanism. The current work suggests a robust and comprehensive treatment for the minimization of dissipation error from these two sources. The optimization technique is used to delay the dissipation of the upwind optimal stencil to those wavenumbers for which the dispersion error is large. However, optimization decreases the formal order of accuracy of the optimal stencil from fifth order to third order. Using the WENO procedure, the third-order accuracy is verified in the smooth region, except the critical point of order two, where the order of accuracy reduces to at least second order. The lost accuracy at the second-order critical point is restored in an attempt to reduce the dissipation induced by the nonlinear adaptive weights. The modification of the nonlinear weights to reduce the dissipation is introduced by redefining them with an additional smoothness indicator. Other suggestions regarding the issues to minimize the dissipation of the nonlinear weights are also reviewed.
Thesis (Ph.D.)--Wichita State University, College of Engineering, Dept. of Aerospace Engineering

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21

Zindo, Atsushi, Yukiharu Ohsawa, Naoki Bessho, and Richard Sydora. "Deep trapping of electrons by oblique shock waves." American Institute of Physics, 2005. http://hdl.handle.net/2237/7038.

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22

Bolme, Cynthia Anne. "Ultrafast dynamic ellipsometry of laser driven shock waves." Thesis, Massachusetts Institute of Technology, 2008. http://hdl.handle.net/1721.1/45160.

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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemistry, 2008.
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Vita.
Includes bibliographical references.
The experimental measurement technique of ultrafast dynamic ellipsometry (UDE) was developed for measuring material motion and changes in optical properties of samples under laser driven shock loading. Ultrafast dynamic ellipsometry, a technique based on space-shifted spectral interferometry, uses the time-dependent frequency of a chirped laser pulse to provide time encoding, allowing the picosecond probing of material dynamics in a single shot. With this technique, the sample is probed at two different incident angles with both s- and p-polarized light, which measures the motion of the material and any change in its complex refractive index. Ultrafast dynamic ellipsometry was first used to ascertain the Hugoniot and the shocked refractive indices of thin polymer films of polycarbonate, poly(methyl methacrylate) (PMMA), poly(chlorotrifluoroethylene-co-vinylidene fluoride) (Kel-F 800), and polydimethylsiloxane (Sylgard 184). Next, UDE was used to measure the Hugoniots of liquid samples over a range of nearly one-dimensional stresses in a single laser shot by capitalizing on the spatial energy distribution of the shock generating laser beam. Using the spatially resolved UDE data, the Hugoniots and shocked refractive indices of cyclohexane, toluene, methanol, and water were measured, each in a single laser shot. Two additional liquids, nitromethane and carbon disulfide, were also investigated with UDE, and both liquids showed evidence of chemical reaction in the first 200 ps after the arrival of the shock wave. Ultrafast dynamic ellipsometry was used in conjunction with high-speed schlieren imaging to determine the nature of the insult provided by ablation of a thin titanium film in optical detonators.
(cont.) We found that the titanium ablates in fragmented sections, which impact the explosive material to initiate the optical detonators. Finally, UDE was applied to the study of metallic phase transitions. The change in the complex refractive index of crystalline silicon was measured during ultrafast laser induced melting. The fabrication of thin metal films of iron and cerium is described, and preliminary UDE data were recorded in an attempt to probe the ??-?? phase transformation in iron and the ??-?? transformation in cerium.
by Cynthia Anne Bolme.
Ph.D.

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23

Kessaratikoon, Prasong. "Shock wave dispersion in weakly ionized gas /." Connect to this resource. (Authorized users only), 2003.

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24

Tabak, Esteban Gregorio. "Focusing of weak shock waves and the von Neumann paradox of oblique shock reflection." Thesis, Massachusetts Institute of Technology, 1992. http://hdl.handle.net/1721.1/108868.

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25

Faddy, James M. "Computational modelling for shock tube flows /." [St. Lucia, Qld.], 2000. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe16174.pdf.

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26

Masse, Robert K. "Fluid dynamics of the shock wave reactor /." Thesis, Connect to this title online; UW restricted, 2000. http://hdl.handle.net/1773/9961.

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27

Boey, Chung Wai. "Investigation of shock wave attenuation in porous materials." Thesis, Monterey, California : Naval Postgraduate School, 2009. http://edocs.nps.edu/npspubs/scholarly/theses/2009/Dec/09Dec%5FBoey.pdf.

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Thesis (M.S. in Mechanical Engineering)--Naval Postgraduate School, December 2009.
Thesis Advisor(s): Hixson, Robert S. Second Reader: McNelley, Terry. "December 2009." Description based on title screen as viewed on January 27, 2010. Author(s) subject terms: Porous foams, dynamic compaction, multi-layered armor, ballistic performance, shock wave attenuation. Includes bibliographical references (p. 89-90). Also available in print.

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28

Kjellander, Malte. "On dynamics and thermal radiation of imploding shock waves." Licentiate thesis, KTH, Mechanics, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-12365.

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Converging cylindrical shock waves have been studied experimentally. Numericalcalculations based on the Euler equations and analytical comparisons basedon the approximate theory of geometrical shock dynamics have been made tocomplement the study.Shock waves with circular or polygonal shock front shapes have been createdand focused in a shock tube. With initial Mach numbers ranging from 2 to4, the shock fronts accelerate as they converge. The shocked gas at the centreof convergence attains temperatures high enough to emit radiation which isvisible to the human eye. The strength and duration of the light pulse due toshock implosion depends on the medium. In this study, shock waves convergingin air and argon have been studied. In the latter case, the implosion lightpulse has a duration of roughly 10 μs. This enables non-intrusive spectrometricmeasurements on the gas conditions.Circular shock waves are very sensitive to disturbances which deform theshock front, decreasing repeatability. Shocks consisting of plane sides makingup a symmetrical polygon have a more stable behaviour during focusing,which provides less run-to-run variance in light strength. The radiation fromthe gas at the implosion centre has been studied photometrically and spectrometrically.Polygonal shocks were used to provide better repeatability. Thefull visible spectrum of the light pulse created by a shock wave in argon hasbeen recorded, showing the gas behaving as a blackbody radiator with apparenttemperatures up to 6000 K. This value is interpreted as a modest estimation ofthe temperatures actually achieved at the centre as the light has been collectedfrom an area larger than the bright gas core.As apparent from experimental data real gas effects must be taken intoconsideration for calculations at the implosion focal point. Ideal gas numericaland analytical solutions show temperatures and pressures approaching infinity,which is clearly not physical. Real gas effects due to ionisation of theargon atoms have been considered in the numerical work and its effect on thetemperature has been calculated.The propagation of circular and polygonal have also been experimentallystudied and compared to the self-similar theory and geometrical shock dynamics,showing good agreement.

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29

Masaki, Tomohiro, Hiroki Hasegawa, and Yukiharu Ohsawa. "Enhanced acceleration of energetic ions by oblique shock waves." American Institute of Physics, 2000. http://hdl.handle.net/2237/7008.

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30

Celliers, Peter Martin. "Dynamics of laser-driven shock waves in fused silica." Thesis, University of British Columbia, 1987. http://hdl.handle.net/2429/26970.

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The formation of a laser-driven shock in fused silica was observed experimentally. Fused silica slabs were irradiated with 0.53 /µm laser light in a pulse of 2 ns FWHM at intensities ranging from 10¹² W/cm² to 5 x 10¹³ W/cm², producing a pressure pulse ranging from < 30 GPa to 500 GPa. Shock trajectories were observed using streaked shadowgram and schlieren methods. The experiment was modelled with a one-dimensional Lagrangean laser-plasma hydrocode. Comparison of the simulation results with the experimental observations indicate that the high pressure shock develops anomalously slowly at intensities > 1 x 10¹³ W/cm². Furthermore the shock displayed non-steady propagation for a transient period following its formation. The non-steady propagation is interpreted to be due to a relaxation process in the phase transformation of the fused silica to the high pressure stishovite phase which occurs in the shock front. The slow formation of the shock at high intensities is consistent with a significant volume collapse (phase transition) possibly induced by isentropic compression; however, this interpretation is uncertain due to the complications introduced by non-equilibrium thermodynamics and the possibility of two-dimensional motion.
Science, Faculty of
Physics and Astronomy, Department of
Graduate

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31

Sato, Masatoshi, Seiji Miyahara, and Yukiharu Ohsawa. "Electron acceleration caused by small pulses in shock waves." American Institute of Physics, 2005. http://hdl.handle.net/2237/7035.

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32

Blanco-Cano, Xochitl Guillermina. "Waves and particles upstream of the earth's bow shock." Thesis, Queen Mary, University of London, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.362331.

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Meli, Athina. "Particle acceleration at relativistic and ultra-relativistic shock waves." Thesis, Imperial College London, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.399116.

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Bartholomeeusen, Gert. "Compound shock waves and creep behaviour in sediment beds." Thesis, University of Oxford, 2003. http://ora.ox.ac.uk/objects/uuid:f1ba2e5c-60b7-4d18-ae02-69356a289290.

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This research is a theoretical, experimental and numerical study of the one-dimensional deformation of suspensions. The study is focussed on the transition between sedimentation and consolidation, and creep during soil consolidation. In the literature, sedimentation, traditional large strain consolidation and creep are explored independently. The theory of sedimentation has been derived in parallel with the mathematical description of shock waves. The large strain consolidation theory of Gibson et al. (1981) has been adopted, and attention is given to the material properties of compressibility and permeability. Traditionally creep has been studied on thin samples, and a review is given to identify parallels with creep behaviour of the thick samples studied here. The experimental work was carried out in the laboratory using settling column tests. During the sedimentation stage, when the soil particles are fluid supported, shock waves were monitored and tracked by means of an X-ray absorption technique to allow for the calculation of experimental flux functions. Settling column experiments on different natural soils have been performed to study the consolidation behaviour by means of the measurement of pore water pressure and X-ray density measurements. An in-depth study of the development of effective stress has been performed to quantify the creep behaviour of the soils studied in a strain rate surface. The sedimentation equation is classified as a hyperbolic partial differential equation. In this kind of equation, discontinuities can propagate, and standard solution methods, eg finite differences, fail to give adequate results. For this reason codes have been developed using the finite volume method (FVM) to solve the sedimentation equation numerically. A standard numerical code has been developed for the solution of the large strain consolidation equation, while for the unified sedimentation-consolidation model the finite volume method (FVM) has been used. The shock waves monitored in the experiments are successfully predicted by the sedimentation model using experimentally derived flux functions. This study made it possible to formulate a physically and mathematically correct definition of the transition from sedimentation to consolidation. The strengths and weaknesses of the traditional large strain consolidation model have been identified by means of an international Class A prediction seminar. A new unified sedimentation-consolidation model is proposed using a flux function, a permeability relationship and a strain rate surface as material functions. Successful predictions of experiments have been performed, showing the transition from sedimentation to consolidation and the inclusion of creep.

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Pike, J. "Analysis of dusty shock waves for a mixed dust." Thesis, Cranfield University, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.385879.

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36

Vanthieghem, Arno. "Theoretical and numerical studies of relativistic collisionless shock waves." Thesis, Sorbonne université, 2019. http://www.theses.fr/2019SORUS398.

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Les ondes de choc relativistes et sans collisions jouent un rôle majeur dans la physique des objets astrophysiques extrêmes, tels que les sursauts gamma, les blazars ou les nébuleuses de vent de pulsar, au sein desquels elles contribuent à la production de distributions non thermiques de particules et rayonnement. Ces ondes de choc résultent de l'interaction, par l'entremise d'une turbulence électromagnétique engendrée par des micro-instabilités, entre un faisceau de particules accélérées par processus de Fermi et le plasma ambiant. La modélisation de leur dynamique constitue un problème complexe, dont le traitement requiert de combiner analyse théorique et simulations numériques de type particle-in-cell (PIC). Après un résumé des concepts et des outils numériques nécessaires à la modélisation du problème, nous étudions l'évolution non-linéaire de l'instabilité de filamentation de courant qui domine la physique du précurseur de tels chocs. Dans un second temps, nous développons un modèle complet de la micro-physique de ces chocs, basé sur la définition d'un référentiel privilégié dans lequel la turbulence est quasi magnétostatique. Ce référentiel nous permet de caractériser le chauffage et le ralentissement du plasma de fond ainsi que la dynamique du faisceau. Pour terminer, nous explorons l'effet d'un éjecta neutronique sur l'évolution du choc avant dans un sursaut gamma. Pour chaque étude, nos prédictions théoriques sont étayées par des simulations PIC de haute résolution
Collisionless relativistic shock waves play a major role in extreme astrophysical objects such as gamma-ray bursts, blazars and pulsars wind nebulae, in which they are held responsible for producing nonthermal particle and radiation distributions. Without an external magnetic field, these shocks stem from the interaction, mediated by microinstabilities, of a beam of Fermi-accelerated particles with the ambient plasma. There results an electromagnetic turbulence that scatters both the beam and plasma particles. While the background plasma is mainly slowed down and heated, a fraction of its particles are accelerated to suprathermal energies, thus sustaining the shock wave. Understanding the highly nonlinear physics of such structures requires combining analytical models and large-scale particle-in-cell (PIC) numerical simulations. After a short review of the concepts and numerical techniques used to address the topic, we first examine the evolution of the current filamentation instability, which prevails in the precursor region of initially unmagnetized shocks. We then develop a comprehensive microphysical model of such shocks. To this purpose, we introduce the notion of a preferential frame, in which the microturbulence is quasi-magnetostatic, thus allowing the description of the particle scattering to be greatly simplified. Finally, we analyze the influence of a neutron ejecta propagating upstream of a gamma-ray burst shock. For each study, our model predictions are substantiated by state-of-the-art PIC simulations. particules

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Bergersen, John K. "Effect of surface coating on cylinders subjected to underwater shock." Thesis, Monterey, Calif. : Naval Postgraduate School, 1992. http://handle.dtic.mil/100.2/ADA257299.

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Thesis (M.S. in Mechanical Engineering)--Naval Postgraduate School, September 1992.
Thesis Advisor: Kwon, Young W. "September 1992." Description based on title screen as viewed on March 10, 2009. Includes bibliographical references (p. 115-116). Also available in print.

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Lau-Chapdelaine, Sébastien She-Ming. "Viscous Triple Shock Reflections Relevant to Detonation Waves, and Detonation Dynamics Predicted by the Fickett Model." Thesis, Université d'Ottawa / University of Ottawa, 2019. http://hdl.handle.net/10393/39530.

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Two aspects of detonation dynamics are addressed in this thesis by articles. The first part of the thesis investigates shock reflection phenomena believed to be responsible for enhancing reaction rates in detonations, namely Kelvin-Helmholtz instability and Mach stem bifurcation caused by forward jetting. Three papers are presented. The first numerically investigates shock reflections from a wedge under detonation-like conditions. A state of the art solver of the Euler equations is used. The shock reflection configuration is shown to depend on solver type, wedge implementation, and resolution. The type of reflection (i.e. regular or irregular) is found to depend on corner geometry, even far from the corner, showing initial conditions can play important roles in shock reflections. These complications are addressed with shock-resolved viscous simulations and a new initial condition: the triple point reflection. The numerical method is demonstrated in the second paper, and the presence of Kelvin-Helmholtz instability is investigated. Viscosity is found to play an important role in delaying the instability, which is found not to be a likely source of reaction acceleration on time scales commensurate with autoignition behind the Mach stem, but may become important on scales associated with the detonation cell. Mach stem bifurcations are investigated experimentally and numerically in the third paper. Experimental shock reflections are performed from a free-slip boundary in gases with differing isentropic exponents. Bifurcations are found in experiments, viscous and inviscid simulations. Viscosity is found to delay bifurcations. Inviscid simulations are used to approximate the limits of Mach stem bifurcation in the phase space of Mach number, isentropic exponent, and reflection angle. A maximum isentropic exponent is found beyond which bifurcations do not occur, matching the irregular/regular boundary of the detonation cellular structure. Flow field instability is found in experiments at high Mach number and low isentropic exponent. The second part of the thesis, comprised of one paper, investigates the dynamics of detonations with multiple thermicity peaks using Fickett's detonation analogue. Steady state analysis predicts multiple possible steady states, but only the fastest is singularity-free. Simulations show other solutions develop shock waves that eventually establish a detonation travelling at the fastest velocity allowed by the generalized Chapman-Jouguet criterion. Characteristic and linear stability analysis shows these shocks are found to arise due to instability at the sonic points.

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Quirk, J. J. "An adaptive grid algorithm for computational shock hydrodynamics." Thesis, Boston Spa, U.K. : British Library Document Supply Centre, 1991. http://ethos.bl.uk/OrderDetails.do?did=1&uin=uk.bl.ethos.280913.

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Ernst, Scott. "A nonlinear investigation of corrugation instabilities in magnetic accretion shocks." Thesis, University of Oregon, 2011. http://hdl.handle.net/1794/11229.

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xi, 172 p. : ill. (some col.)
Accretion shock waves are present in many important astrophysical systems and have been a focus of research for decades. These investigations provide a large body of understanding as to the nature, characteristics, and evolutionary behaviors of accretion shock waves over a wide range of conditions. However, largely absent are investigations into the properties of accretion shock waves in the presence of strong magnetic fields. In such cases these strong magnetic fields can significantly alter the stability behaviors and evolution of the accretion shock wave through the production and propagation of magnetic waves as well as magnetically constrained advection. With strong magnetic fields likely found in a number of accretion shock systems, such as compact binary and protostellar systems, a better understanding of the behaviors of magnetic accretion shock waves is needed. A new magnetohydrodynamics simulation tool, IMOGEN, was developed to carry out an investigation of instabilities in strong, slow magnetic accretion shocks by modelling their long-term, nonlinear evolution. IMOGEN implements a relaxed, second-order, total variation diminishing, monotonic upwind scheme for conservation laws and incorporates a staggered-grid constrained transport scheme for magnetic advection. Through the simulated evolution of magnetic accretion shocks over a wide range of initial conditions, it has been shown, for sufficiently high magnetic field strengths, that magnetic accretion shocks are generally susceptible to corrugation instabilities, which arise in the presence of perturbations of the initial shock front. As these corrugation instabilities grow, they manifest as magnetic wave propagation in the upstream region of the accretion column, which propagate away from the accretion shock front, and as density columns, or fingers, that grow into the higher density downstream flow, defined and constrained by current loops created during the early evolution of the instability.
Committee in charge: Dr. James Schombert, Chair; Dr. James Imamura, Advisor; Dr. Alan Rempel, Member; Dr. John Toner, Member; Dr. Kent Stevens, Outside Member

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Sanderson, Simon R. "Shock wave interaction in hypervelocity flow /." Web site:, 1995. http://etd.caltech.edu/etd/available/etd-11092004-094744/.

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42

Doughty, Roger L. "Effects of multiple incident shock waves on the flow in a transonic turbine cascade." Diss., This resource online, 1994. http://scholar.lib.vt.edu/theses/available/etd-06062008-164902/.

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43

Schilling, Mark Wesley. "Hydrodynamic Shock Wave Effects on Protein Functionality." Thesis, Virginia Tech, 1999. http://hdl.handle.net/10919/35132.

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USDA Select bovine Biceps femoris (BF) samples were divided into four sections and randomly assigned to three hydrodynamic shock wave (HSW) treatments and a control. Different amounts of explosive (105 g, H1; 200 g, H2; 305 g, H3) were suspended in the center of the hemishell tank, 26.7 cm above the vacuum packaged beef placed on the bottom center of that water-filled tank and detonated, representing three HSW treatments. In addition, BF steaks (2.54-cm thick) from a different and limited common source (2 muscles) were packaged with each HSW designated BF section. These served as internal refernce steaks (IRS) for the six replications to determine if the HSW treatments physically altered the structural integrity of the meat. H1 and H3 decreased (P<0.05) Warner-Bratzler shear values of the IRS from 3.86 and 3.99 kg (controls) to 3.01 and 3.02 kg (HSW), respectively. H2 shear values, 3.86 (control) to 3.46 kg (HSW) were not different (P> 0.05). HSW and control BF sections were analyzed for protein solubility and then used to manufacture frankfurters formulated with 2.0% NaCl, 0.5 % sodium tripolyphosphate, 156 ppm sodium nitrite, 0.42 % sodium erythorbate, 2.0 % sucrose, and 25 % water. Frankfurters (cooked to 71 C) were evaluated for cooking yield, CIE L*a*b*, nitrosylhemochrome, Texture Profile Analysis (hardness, cohesiveness), and stress and strain (torsion testing). Compared to the control samples, the HSW did not affect (P>0.05) myofibrillar or sarcoplasmic protein solubility, cooking yield, or color. Textural properties and gel strength of the frankfurters were not affected (P>0.05) by the HSW. These results indicate that beef trim obtained from HSW processed meat can be used interchangeably with normal meat trim in the production of further processed meats since the functionality of meat protein is not affected significantly by the HSW process.
Master of Science

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44

Al-Ghoul, Mazen. "Studies in generalized hydrodynamics for chemical reactions and shock waves." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape16/PQDD_0028/NQ29872.pdf.

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Liefvendahl, Mattias. "Stability results for viscous shock waves and plane Couette flow." Doctoral thesis, Stockholm, 2001. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3241.

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46

Gloag, Jonathan Michael. "Research into weak interplanetary shock waves using the Ulysses spacecraft." Thesis, Imperial College London, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.401735.

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47

Reese, Jason M. "On the structure of shock waves in monatomic rarified gases." Thesis, University of Oxford, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.358731.

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48

Noll, Scott Allen. "Residual stress fields due to laser-pulse-generated shock waves." The Ohio State University, 1999. http://rave.ohiolink.edu/etdc/view?acc_num=osu1407411599.

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49

Gacek, Sobieslaw Stanislaw. "Molecular dynamics simulation of shock waves in laser-material interaction." [Ames, Iowa : Iowa State University], 2009.

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Scott, Michael Brian. "General relativistic shock-waves propagating at the speed of light /." For electronic version search Digital dissertations database. Restricted to UC campuses. Access is free to UC campus dissertations, 2002. http://uclibs.org/PID/11984.

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