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1
Wrenninge, Magnus. „Fluid Simulation for Visual Effects“. Thesis, Linköping University, Department of Science and Technology, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-2347.
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This thesis describes a system for dealing with free surface fluid simulations, and the components needed in order to construct such a system. It builds upon recent research, but in a computer graphics context the amount of available literature is limited and difficult to implement. Because of this, the text aims at providing a solid foundation of the mathematics needed, at explaining in greater detail the steps needed to solve the problem, and lastly at improving some aspects of the animation process as it has been described in earlier works.
The aim of the system itself is to provide visually plausible renditions of animated fluids in three dimensions in a manner that allows it to be usable in a visual effects production context.
The novel features described include a generalized interaction layer providing greater control to artists, a new way of dealing with moving objects that interact with the fluid and a method for adding source and drain capabilities.
2
Schwabe, Mierk. „Dynamical effects in fluid complex plasmas“. Diss., lmu, 2009. http://nbn-resolving.de/urn:nbn:de:bvb:19-109050.
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3
Kwok, Peter (Peter Yu) 1975. „Fluid effects in vibrating micromachined structure“. Thesis, Massachusetts Institute of Technology, 1999. http://hdl.handle.net/1721.1/9419.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1999.Includes bibliographical references (p. 114-116).
This thesis presents the study of the fluid damping and surfboarding effects for the tuning fork gyroscope. The quality factors in the drive and sense axes will be evaluated and compared with the experimental results for a range of pressures. The effects of the holes and the proof mass thickness (chimney) will be derived and discussed, and a parametric study on several design parameters will be performed. An analytical model based on the classic slider bearing with slip boundary will be derived and numerical models will be developed to estimate the lift force from "surfboarding", and the numerical solution will be compared with the bias of the 1FG from experiments over a range or pressures. Original contribution includes 1 ). Experimental work performed to obtain the inphase bias and quality factors in the drive and sense axes, 2). Data post-processing technique developed to obtain the structural and fluid damping of the tuning fork gyroscope, 3). Numerical simulations of the normalized Reynolds squeeze film equation and normalized Reynolds slider bearing equation on nontrivial geometry, and 4). Network model developed to solve for the pressure distribution from surfboarding with the chimney effect.
by Peter Kwok.
S.M.
4
Wang, Zhongzheng. „Capillary Effects on Fluid Transport in Granular Media“. Thesis, The University of Sydney, 2021. https://hdl.handle.net/2123/25895.
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Fluid transport phenomena in granular media are of great importance due to various natural and industrial applications, including CO2 sequestration, enhanced oil recovery, remediation of contamination, and water infiltration into soil. Although numerous studies exist in the literature with aims to understand how fluid properties and flow conditions impact the transport process, some key mechanisms at microscale are often not considered due to simplifications of physical phenomenon and geometry, limited computational resources, or limited temporal/spatial resolution of existing imaging techniques.
In this Thesis, we investigate fluid transport phenomena in granular media with a focus on the capillary effects. We move from relatively simple scenario on patterned surfaces to more complex granular media, tackling a variety of liquid-transport related problems that all have extensive industrial applications. The bulk of this Thesis is composed of six published papers. Each chapter is prefaced by an introductory section presenting the motivation for the corresponding paper and its context within the greater body of work.
This Thesis reveals the impact of some previously neglected physical phenomena at microscale on the fluid transport in granular materials, providing new insights and methodology for describing and modelling fluid transport process in porous media.
5
Ozkok, Okan. „Investigation Of Fluid Rheology Effects On Ultrasound Propagation“. Master's thesis, METU, 2012. http://etd.lib.metu.edu.tr/upload/12614621/index.pdf.
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In this study, a mathematical model is developed for investigating the discrete sound propagation in viscoelastic medium to identify its viscoelastic properties. The outcome of the model suggests that pulse repetition frequency is a very important parameter for the determination of relaxation time. Adjusting the order of magnitude of the pulse repetition frequency, the corresponding relaxation time which has similar magnitude with pulse repetition frequency is filtered while the others in the spectrum are discarded. Discrete relaxation spectrum can be obtained by changing the magnitude of the pulse repetition frequency. Therefore, the model enables to characterize the relaxation times by ultrasonic measurements.
6
Lundberg, Lukas. „Art Directed Fluid Flow With Secondary Water Effects“. Thesis, Linköpings universitet, Medie- och Informationsteknik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-81808.
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This thesis describes methods for applying secondary water effects as spray, foam, splashes and mist to a fluid simulation system. For an art direction control over the base fluid flow a Fluid Implicit Particle solver with custom fields is also presented. The methods build upon production techniques within the visual effects industry, fluid dynamics and relevant computer graphics research. The implementation of the methods is created within Side Effects Software Houdini.
7
Hughes, Jason Peter. „Fluid inertia and end effects in rheometer flows“. Thesis, University of Plymouth, 1998. http://hdl.handle.net/10026.1/1889.
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This thesis is concerned with the characterisation of the flow behaviour of inelastic and viscoelastic fluids in steady shear and oscillatory shear flows on commercially available rheometers. The first part of this thesis is concerned with a linear viscoelastic theory to describe the oscillatory shear flow behaviour of fluids on a Weissenberg rheogoniometer. A fluid inertia perturbation analysis is used to produce analytical formulae for correcting complex viscosity data for first and second order fluid inertia effects. In order to validate the perturbation theory we perform a simulation of the oscillatory shear flow behaviour of Newtonian and single element Maxwell fluids on a Weissenberg rheogoniometer. A theoretical prediction of end effects and fluid inertia effects on steady shear viscosity measurements of Newtonian fluids in a recessed concentric cylinder geometry is developed for a GSR controlled stress rheometer and a Weissenberg rheogoniometer. The relevant equations are solved using a perturbation analysis which is valid for low Reynolds number flows. From this theory correction formulae are produced to compensate for end effects and second order fluid inertia effects in steady shear flows on these instruments. End effects and fluid inertia effects are also investigated for power law shear thinning fluids. The final part of the thesis is concerned with a theoretical prediction of the end effect of a recessed concentric cylinder geometry on complex viscosity measurements of a generalised linear viscoelastic fluid. The linear viscoelastic theory is carried out for oscillatory shear flows on a CSR controlled stress rheometer and a Weissenberg rheogoniometer. A fluid inertia perturbation analysis is used to produce analytical formulae to correct complex viscosity data for end effects and second order fluid inertia effects. Numerically simulated oscillatory shear data is used to establish the limitations of the second order fluid inertia correction formulae which include end effects.
8
Liu, Man. „Fluid-structural interaction effects on vibrations of pipework“. Thesis, University of Aberdeen, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.385271.
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9
Jeon, Jaewoo. „Displacing visco plastic fluid with Newtonian fluid in a vertical circular pipe with buoyancy effects“. Thesis, University of British Columbia, 2017. http://hdl.handle.net/2429/60318.
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In this thesis, displacement flows in a vertical pipe are studied when Newtonian fluids displace visco-plastic fluids. The density combinations between displacing and displaced fluids are varied from density unstable through iso-density to density stable, and captured dimensionlessly using Atwood numbers. In density unstable cases, three flow regimes are classified: central, mixed/turbulent and asymmetric regimes. These regimes are partially classified by a buoyancy parameter. However, we found that the buoyancy parameter has a limit in classifying the flow regimes. Once the flow enters the turbulent regime, spread of the dispersive mixed region is characterized by fitting the mean concentration changes to the solution of an 1D linear advection diffusion equation, i.e., turbulent diffusivity (or dispersivity) dominates in this regime. In iso-density cases, all flows are classified in central regime but the shapes of static layers are classified as: smooth, wavy and corrugated. We found that Re, Newtonian Reynolds number, differentiates the static layer shapes. Transitional Reynolds numbers are identified as Re = 345 for corrugated to wavy and Re = 1000 for wavy to smooth. The transitional Re for turbulent regime is identified at around 4000. Lastly, we observed that viscous fingering is common in density stable cases. Viscous fingering is observed for large effective viscosity, ratio of a viscoplastic fluid to a Newtonian fluid, and a ratio of shear stress to a yield stress of a displaced fluid ratio is small, and starts from an elongated thin layer finger. In the regime, the wall shear stress is too small to yield the visco-plastic fluid from the wall and the mobility of the displacing fluid is relatively high, so it seeks a way to channel though the visco-plastic fluid. The transitional Re for mixed/turbulent regime was not found within our experimental range. The displacement efficiency, described in the ratio of a front velocity to a mean velocity in density stable cases increases by approximately 15%, compared to density unstable and iso-density. Density unstable experiments can have better efficiency than iso-density experiments due to entering mixing regime in lower Reynolds numbers. However, the differences in the efficiency are generally small.Applied Science, Faculty of
Mechanical Engineering, Department of
Graduate
10
Sanders, Barry. „The effects of sodium chloride ingestion on fluid balance and body fluid distribution during exercise“. Master's thesis, University of Cape Town, 1993. http://hdl.handle.net/11427/27124.
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The aim of the first experiment of this thesis was to determine whether the ingestion of a concentrated sodium chloride solution (100mEq/1) during exercise would expand the plasma volume when fluid was ingested at approximately half the rate at which it was being lost as sweat. Six male cyclists exercised for 90 minutes in the heat (32 ± 1 °C, 55 ± 5% RH) at 66 ± 1 % of VO₂ₘₐₓ while ingesting either no fluid CNF), water (W), or a saline CS) solution (100mEq/1). In the Wand S trials, subjects drank 400ml of the fluid immediately prior to commencing exercise, and 100ml of fluid every 10 minutes during exercise until 80 minutes. In the S trial sodium chloride was ingested in capsules. One capsule containing 0.585g of sodium chloride was ingested with every 100ml of water. At the end of the 90 minute exercise bout they rested in a sitting position for one hour in cool conditions (22 ± 1 °C and 70 ± 5% RH). After the initial drop in plasma volume due to the onset of exercise. plasma volume decreased progressively during the NF trial and was significantly less than the 10 minute value at 80 and 90 minutes (p<0.0033). At 40, 60, 80 and 90 minutes of exercise, the plasma volume in the NF trial was significantly less than in the W and the S trials (p<0.05). There was no significant difference between the W and the S trials at any time. Further, after the initial drop in plasma volume due to the onset of exercise. plasma volume did not decrease any further in either the W or the S trial. Plasma sodium concentrations in the NF and the S trial were significantly elevated at 40, 60, 80 and 90 minutes (p<0.0033). Plasma sodium concentration in the NF and the S trials were also significantly higher than in the W trial at 80 and 90 minutes of exercise (p<0.05). Since the ingestion of a sodium chloride solution containing 100mEq/1 did not have a beneficial effect on plasma volume and plasma sodium concentration, when fluid ingestion rates were approximately half of the rate of sweat loss, it is concluded the under these conditions, the ingestion of a concentrated sodium chloride beverage has no advantage over the ingestion of water. The aim of the second experiment of this thesis was to determine the effect of varying concentrations of sodium chloride ingestion on fluid balance, when the rate of fluid ingestion matched the sweat rate. Six male cyclists cycled for 4 hours at 55% of VO₂ₘₐₓ in mild conditions (20 ± 1°c and 70 ± 5% RH), while ingesting either a low salt (LS) (4.6 mEq/1), a medium salt (MS) (50 mEq/1) or a high salt (HS) (100 mEq/1) beverage. Each beverage also contained a glucose polymer in an 8% concentration (8g/100ml). The subjects ingested 400ml of beverage immediately prior to commencement of exercise, and 150ml of fluid every 10 minutes during exercise until 220 minutes. Sodium chloride in the MS and HS trials was given to the subjects as supplemental gel capsules so that the drink was palatable. At the end of exercise, subjects recovered in a sitting position for 30 minutes. At the end of the 4 hours of exercise, fluid loss via the urine was significantly greater in the LS and the MS trials than in the HS trial (p<0.05). As a result, the fluid deficits in the LS and the MS trials were significantly greater than the fluid deficit in the HS trial. There was no significant difference between the MS and the LS trials for urinary fluid loss. During the 4 hour exercise bout, plasma sodium concentrations in the LS, the MS and the HS trials were not significantly different from one another, nor were they significantly different from resting values. There was no significant difference in the rectal temperature response to exercise in the three trials. It can therefore be concluded that in conditions where fluid ingestion matches sweat rate, attenuation of urinary fluid loss to optimise fluid replacement, relies on the ingestion of sodium chloride in quantities greater than that lost in the sweat. Therefore, for the ingestion of sodium chloride in excess of that which is currently available in sports drinks to beneficial, fluid must be ingested in volumes matching sweat loss.
11
Annaratone, B. M. „Magnetohydrodynamic effects in a weldpool model“. Thesis, University of Oxford, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.382613.
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12
Avcu, Mehmet. „Fluid-structure interaction effects resulting from hull appendage coupling“. Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2005. http://library.nps.navy.mil/uhtbin/hyperion/05Sep%5FAvcu.pdf.
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13
Thompson, Robert Lee. „Supercritical fluid solvent effects on a diels-alder reaction“. Thesis, Georgia Institute of Technology, 1996. http://hdl.handle.net/1853/10021.
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14
Doty, Sherry D. „Fluid shear stress effects on fibronectin in endothelial cells“. Thesis, Georgia Institute of Technology, 1989. http://hdl.handle.net/1853/19073.
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15
Albrecht, Karen A. „Observation scale effects on fluid transport behavior of soil“. Thesis, Virginia Tech, 1985. http://hdl.handle.net/10919/43037.
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Variabilities of hydraulic and solute transport properties of soil are examined at three scales: pore-scale, sample volume-scale, and field-scale. Undisturbed soil cores were taken at 19 subsites spaced logarithmically along a 150 m line transect in a Groseclose mapping unit near Blacksburg; Virginia. Three core sizes were taken at each subsite at the soil surface and 0.5 m depth. 'Small' cores were-40x54 mm; 'medium' cores were 60X100 mm; and 'large' cores were 100x150 mm. Macropore effects on solute transport
were evaluated using monocontinuum and bicontinuum models. Bicontinuum-predicted solute breakthrough curves
(BTC) closely agreed with observed BTC data with mean errors of reduced concentrations
Master of Science
16
McBean, Ivan William 1974. „Simulation of 3-dimensional aeroelastic effects in turbomachinery cascades“. Monash University, Dept. of Mechanical Engineering, 2002. http://arrow.monash.edu.au/hdl/1959.1/7690.
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17
Brotherton-Ratcliffe, Rupert Victor. „Boundary-layer effects in liquid-layer flows“. Thesis, University College London (University of London), 1987. http://discovery.ucl.ac.uk/1317966/.
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In this thesis we describe various regimes of practical and theoretical significance that arise in the laminar two-dimensional flow of a layer of an incompressible viscous fluid over a solid surface at high Reynolds number. In Part I we consider steady flows over a distorted rigid surface. Almost uniform flows are considered first, when the distortion is sufficient to provoke a viscous-inviscid interaction, and therefore boundary-layer separation. The two cases of supercritical and subcritical flow have quite distinct features, and are discussed separately. The governing equations in each case require a numerical treatment in general, but analytical progress has been made in certain important regimes e. g. when the distortion is relatively small and linearisation of the problem is possible. Next, the grossly separated motion of fully-developed flows over large obstacles, with dimensions of the order of the depth of the liquid layer, is studied on the basis of inviscid Kirchhoff free-streamline theory. Some comparisons of the theory with recent experiments are also given. In Part II we discuss unsteady and instability aspects of two-dimensional flow over a flat surface. It is shown that viscous and mean flow effects can combine to give instability in some cases, whereas previous studies have only found viscous effects to be stabilising. Unsteadiness of a two-layer fluid flow, with fluids of different viscosity and density, and incorporating surface tension effects, is also discussed. In Part III, deviating from the above theme slightly, we discuss briefly the steady, high-Reynolds-number flow in an asymmetric branching channel, again in the context of viscous-inviscid interactions. The asymmetry is found to force a large-scale response both up- and downstream of the start of the bifurcation. The aim is to find the pressure distributions on the channel walls and on the dividing body. This requires the use of a Wiener-Hopf technique in view of the mixed boundary conditions.
18
Thiriat, Paul. „FLUID-STRUCTURE INTERACTION : EFFECTS OF SLOSHING IN LIQUID-CONTAINING STRUCTURES“. Thesis, KTH, Bro- och stålbyggnad, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-125353.
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This report presents the work done within the framework of my master thesis in the program Infrastructure Engineering at KTH Royal Institute of Technology, Stockholm. This project has been proposed and sponsored by the French company Setec TPI, part of the Setec group, located in Paris. The overall goal of this study is to investigate fluid-structure interaction and particularly sloshing in liquid-containing structures subjected to seismic or other dynamic action. After a brief introduction, the report is composed of three main chapters. The first one presents and explains fluid-structure interaction equations. Fluid-structure interaction problems obey a general flow equation and several boundary conditions, given some basic assumptions. The purpose of the two following chapters is to solve the corresponding system of equations. The first approach proposes an analytical solution: the problem is solved for 2D rectangular tanks. Different models are considered and compared in order to analyze and describe sloshing phenomenon. Liquid can be decomposed in two parts: the lower part that moves in unison with the structure is modeled as an impulsive added mass; the upper part that sloshes is modeled as a convective added mass. Each of these two added mass creates hydrodynamic pressures and simple formulas are given in order to compute them. The second approach proposes a numerical solution: the goal is to be able to solve the problem for any kind of geometry. The differential problem is resolved using a singularity method and Gauss functions. It is stated as a boundary integral equation and solved by means of the Boundary Element Method. The linear system obtained is then implemented on Matlab. Scripts and results are presented. Matlab programs are run to solve fluid-structure interaction problems in the case of rectangular tanks: the results concur with the analytical solution which justifies the numerical solution. This report gives a good introduction to sloshing phenomenon and gathers several analytical solutions found in the literature. Besides, it provides a Matlab program able to model effects of sloshing in any liquid-containing structures.
19
Demyttenaere, Sebastian. „The effects of pneumoperitoneum and fluid administration on renal perfusion /“. Thesis, McGill University, 2006. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=97941.
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Minimally invasive surgeons are performing increasingly complex and time-consuming procedures on increasingly frail patients. Understanding the complex physiologic consequences of pneumoperitoneum is therefore of critical importance. This is especially true in the field of live laparoscopic donor nephrectomy where a thorough understanding of the effects of pneumoperitoneum on renal perfusion and function is mandated. A systematic review of the literature is undertaken and reveals that both renal perfusion and function are decreased during pneumoperitoneum. Next, a porcine model is established and used to compare the effects of aggressive fluid hydration (28cc/kg/h) versus maintenance fluid hydration (5cc/kg/h). We demonstrate that renal perfusion is preserved with aggressive fluid hydration. Finally, a noninvasive fluid administration algorithm based on esophageal Doppler stroke volume measurements is assessed. Using this technique, renal perfusion is preserved during pneumoperitoneum, using less fluid (10cc/kg/h) than a bolus group (25cc/kg/h). Fluid administration via the esophageal Doppler is a noninvasive way to target individual hemodynamics to maintain renal perfusion during pneumoperitoneum.
20
Conner, Ryan P. „Fluid Structure Interaction Effects on Composites Under Low Velocity Impact“. Thesis, Monterey, California. Naval Postgraduate School, 2012. http://hdl.handle.net/10945/7324.
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In this study composite materials were tested in different fluid environments to determine the role of Fluid Structure Interaction with these composites under a lower velocity impact. The purpose of this research is to develop a better understanding of possible marine applications of composite materials. This was done using a low velocity impact machine and two composite types. The first composite is made from a multi-ply symmetrical plain weave 6 oz. E-glass skin. The test area of the composites is 12 in by 12 in (30.5 cm by 30.5 cm) with clamped boundary conditions. The testing was done using a drop weight system to impact the center of the test area. A Plexiglas box in conjunction with the impact machine was used to keep the top of the composite sample dry while it was submerged in approximately 15 inches (38.10 cm) of water. The second composite type was constructed using the same methods, but was made from a Carbon Fiber Reinforced Polymer (CFRP) instead of the E-glass skin. These samples were pre-cracked and tested using the same impact machine in 15 inches (38.10 cm) of water. The overall size of these samples was 42 cm long and 3 cm wide forming a long thin rectangular shape. The test area of these samples was a 20 cm long section of the sample with the outsides being clamped to achieve the desired boundary conditions. Two variations of these samples were tested. The first was reinforced with Multi-Walled Carbon Nanotubes (MWCNTs) and the second had no reinforcements at the interface layer in front of the pre-cracks. Output from both tests was recorded using strain gauges and a force impact sensor. The results show that an added mass from the water plays a large role in the Fluid Structure Interaction with composites due to the similar densities of water and the composites.
21
Umar, U. M. „The effects of antirheumatic drugs on human synovial fluid composition“. Thesis, Bucks New University, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.371231.
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GARCIA, OLGA CECILIA CARVAJAL. „SANDSTONE SEISMIC MODELING: EFFECTS OF VELOCITY DISPERSION AND FLUID TYPE“. PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2008. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=11890@1.
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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIROAGÊNCIA NACIONAL DE PETRÓLEO
O conhecimento do que acontece no reservatório em produção a partir de variações temporais dos atributos sísmicos devido aos processos dinâmicos vem atingindo um valor crescente na indústria do petróleo, especialmente em arenitos. Este processo possui vários desafios, focados em grande parte a desvendar a superposição dos diferentes efeitos provocados pelas mudanças do reservatório nos dados sísmicos. As propriedades sísmicas são afetadas de maneira complexa por vários fatores, sendo a saturação um dos mais importantes, principalmente em rochas porosas como o arenito. Esta propriedade influencia no módulo elástico da rocha e sua resposta sísmica e, ao mesmo tempo, introduz dispersão da velocidade (variação da velocidade com a freqüência). A transição de fluido efetivo (distribuição homogênea e menores velocidades) para fluido com distribuição heterogênea (e maiores velocidades) estabelece um mecanismo de dispersão presente para freqüências sísmicas in situ, especialmente no arenito. O método mais utilizado para aplicar a técnica de substituição de fluidos se baseia na teoria de Gassmann (1951), que considera o meio poroso estático (estado de isostress), onde o fluido não é afetado pela perturbação da onda. No entanto, pesquisas mostram que as velocidades acústicas em rochas saturadas de fluido dependem da freqüência, do tipo de fluido e sua distribuição no meio poroso, viscosidade e outras propriedades que tornam as ondas dispersivas. Neste trabalho são realizadas simulações de fluxo de reservatórios, transformações de física de rochas, upscaling e modelagem sísmica em cenários de injeção de gás com o objetivo de esclarecer a importância de levar em conta a dispersão da velocidade na análise time-lapse. Para isso, são analisados para cada modelo mapas de saturação, velocidade, impedância e sismogramas sintéticos (seções de contraste) calculados com as teorias de substituição Gassmann (1951) e Mavko E Jizba (1991). Os resultados mostram que a resposta sísmica pode ter um incremento de até 15 por cento quando a dispersão devida ao fluxo local é considerada. Porosidade e tortuosidade são parâmetros essenciais que influenciam de maneira diferente na resposta sísmica.
The evaluation of reservoir dynamics during production through time-lapse interpretation has reached a substantial importance in the petroleum industry, mainly in sandstones. This evaluation presents many challenges, mainly concerned to unmask the overlapping of different effects in seismic data due to reservoir changes. Several factors affect seismic properties and saturation is one of the most important. This property influences the rock bulk modulus and seismic response and also causes a velocity dependence on the frequency. This phenomenon is known as velocity dispersion. Furthermore, the transition from effective homogeneous fluid to heterogeneous saturation represents a dispersion mechanism that appears for seismic frequencies in situ in sandstones. The most commonly method used to perform the fluid substitution technique is based in Gassmann theory (1951). This approach considers a static porous media (isostress condition), where fluid is not affected by wave propagation. However, it is well known that acoustic velocities in fluid saturated rocks depends on frequency, according to fluid type and distribution on porous media, viscosity, and others properties that become waves dispersive. In this work reservoir flow-simulation, rock physics transformations, upscaling and seismic modeling were performed in gas injection scenarios. Synthetic seismograms and some contrast sections were generated using Gassmann (1951) and Mavko & Jizba (1991) substitution theories. The goal is to clarify the relevance of considering velocity dispersion on time-lapse seismic analyzing possible differences in the seismic parameters. Results show that seismic response could increase in 15% when squirt flow dispersion is considered. Porosity and tortuosity are essential parameters to analyze seismic response.
23
Zhao, Xiaomin. „Effects of heterogeneities on fluid flow and borehold permeability measurements“. Thesis, Massachusetts Institute of Technology, 1994. http://hdl.handle.net/1721.1/11933.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 1994.Includes bibliographical references (leaves 216-221).
by Xiaomin Zhao.
Ph.D.
24
Gerova, Klementina. „Thermo-fluid effects associated with modelling subscale automotive heat exchangers“. Thesis, Cranfield University, 2015. http://dspace.lib.cranfield.ac.uk/handle/1826/9875.
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Automotive components are tested extensively in wind tunnels by automotive manufacturers and race teams. This is usually achieved using an accurate scale model representation of the component within the wind tunnel. Automotive heat exchangers, however, are comprised of numerous intricate geometries and are therefore impractical to produce at model scale. Instead they are simply modelled as pressure drops, achieved using a thin mesh or honeycomb of known porosity. Most commercial computational fluid dynamics solvers ignore the geometry of the heat exchanger and instead model it as a discontinuity with a known pressure drop and heat transfer. The pressure drop across an automotive heat exchanger, however, was found to vary with both the coolant temperature and the angle of inclination of the heat exchanger. This thesis initially presents a relationship between the pressure drop coefficient and the inclination angle for varying media porosities. Mathematical relationships for inclination angles of 0°, 15°, 30° and 45°. were derived relating this pressure drop coefficient to the porosity of the media. Weighted least squares is proposed over ordinary least squares when obtaining the Forchheimer equation coefficients from experimental measurements. Investigation extends into the thermo-fluid effects on a full scale automotive heat exchanger when inclined at 0 °, 15°, 30° and 45°. It was found, depending on the angle, that there was a difference in the pressure drop of up to 10% between the unheated and heated (100 C) heat exchanger. Based on the proposed mathematical relationship, this correlated to a 4% decrease in porosity in order to accurately model the automotive heat exchanger at subscale. The thesis concludes with experimental and numerical investigation into the heat transfer on a hydrodynamically and thermally developing ow within a radiator channel. Laser doppler anemometry measurements recorded a 1.5% increase in the centreline velocity compared to 0.8% obtained from numerical simulation.
25
Hou, Lei. „The effects of flow on resistive instabilities in magnetohydrodynamics“. Thesis, University of Abertay Dundee, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.386399.
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Kerr, O. S. „Horizontal effects in double-diffusive convection“. Thesis, University of Bristol, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.380229.
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Brackbill, Tim. „Experimental investigation on the effects of surface roughness on microscale liquid flow /“. Online version of thesis, 2008. http://hdl.handle.net/1850/6136.
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Seto, Mae L. „Flow interference effects between two circular cylinders of different diameters“. Thesis, University of British Columbia, 1990. http://hdl.handle.net/2429/29762.
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This thesis investigates different examples of action at a distance, namely the interaction
of two circular cylinders of different diameters and the interaction of a cylinder with a wall in various arrangements. Action at a distance modifies both the lift and drag of each one of the objects. The fluid flow interaction between a circular cylinder (of diameter D) with a wall, and a circular cylinder with a smaller (¼D) circular cylinder at Reynolds numbers of ≈ 10,000 were of interest. Manifestations
of the interactions include mutual changes in the lift and drag forces, phase, onset and frequency of vortex shedding on the circular cylinders/wall. A novel force measurement device for lift and drag of circular cylinders and a data acqusition system was built to realize the above experiments in a water towing tank. The system was capable of simultaneously measuring lift and drag on two circular cylinders with time resolution and correlating these measurements with flow field pictures. Measurements of the lift and drag and phase, onset and frequency of vortex shedding were taken on the large and small cylinder simultaneously as a function of the relative position between itself and the smaller cylinder as the two are towed. These measurements make it possible to map out the areas within the cylinders' sphere of influence and measure the intensity of this influence as a function
of the distance between the two cylinders. Every quantity that was mutually altered by the presence of another cylinder is used as measurements of the area of influence for a circular cylinder. It was found in general that the forces act up to a distance of about 3 diameters in the lateral direction. It was also noted that pressure fluctuations at the vortex shedding frequency penetrate into the laminar flow region up to about 3D in the lateral direction. The results agree with existing
results for wall/cylinder proximity experiments and flow interference between identical
circular cylinders. A novel method to trigger the onset of vortex shedding for towing tanks was also discovered.Science, Faculty of
Physics and Astronomy, Department of
Graduate
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Harris, Richard. „The modelling and simulation of temperature effects in hydraulic systems“. Thesis, University of Bath, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.256905.
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Rashid, Tariq Mahmood. „Computational modelling of dynamic wind effects relevant to compliant offshore structures“. Thesis, University of Hertfordshire, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.332219.
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Mikulencak, Duane Richard. „Inertial effects in dilute suspensions“. Diss., Georgia Institute of Technology, 2001. http://hdl.handle.net/1853/11026.
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Stangeby, Deborah Kim. „Computational analysis of arterial mass transport, fluid and wall-side effects“. Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0019/NQ53795.pdf.
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Conklin, Brian Scott. „The effects of fluid shear stress on endothelial cell barrier function“. Diss., Georgia Institute of Technology, 2002. http://hdl.handle.net/1853/17221.
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Di, Maso Marie. „Mobile phase modifier effects and electrochemical detection in supercritical fluid chromatography“. Thesis, McGill University, 1990. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=74532.
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The role of mobile phase modifiers in supercritical fluid chromatography (SFC) and their effect on the separation process were investigated. A study of the influence of temperature and density on chromatographic behaviour in supercritical carbon dioxide and four modified carbon dioxide mobile phases demonstrates the importance of both density and mobile phase composition in controlling retention characteristics. The information gained from these studies was used to develop methodology for the separation and detection of a series of phenothiazinone compounds and an assay for L-615,919, 4-chloro-3H-phenothiazin-3-one, in plasma. The development of an analytical method for the analysis of sorbitan trioleate in pharmaceutical formulations demonstrates a unique application of SFC with flame ionization detection (FID) that is not possible by other chromatographic techniques.The feasibility of an electrochemical detection system for SFC has been demonstrated. The design and construction of an electrochemical detector with a platinum ultramicro working electrode and factors influencing its performance are described.
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Galloway, Stuart D. R. „Ambient temperature and exercise capacity : effects of substrate and fluid provision“. Thesis, University of Aberdeen, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.338331.
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This series of studies began with an examination of the effects of ambient temperature (4°C-31°C) on exercise capacity at approximately 70% of VO2max. In this first study, exercise capacity was greatest at 11°C (93.5(16.4) min) and shortest at 31°C (51.6(10.5) min) with intermediate exercise times at 4°C (81.4(27.2) min) and 21°C (81.2(16.3) min). In the trial at 31°C, Tre, Tsk, HR, RPE, and sweat rate were all significantly higher and total CHO oxidation was significantly lower than during any other trial. At 21°C Tre, Tsk, and sweat rate were all significantly higher, and total CHO oxidation lower, than during the 4°C and 11°C trials. These results suggest that heat stress and subsequent failure of thermoregulation or circulatory collapse rather than complete depletion of endogenous muscle glycogen were the possible limiting factors during exercise at 21 and 31°C. At 4°C and 11°C total CHO oxidation was similar suggesting that CHO depletion may have limited exercise capacity in these trials. The reduced exercise capacity at 4°C compared to 11°C can be explained by the observed increase in the rate of CHO oxidation during exercise in the 4°C trial. The second study of this series examined exercise capacity at approximately 60% of VO2max in a hot (30°C) environment with ingestion of either a dilute CHO drink (2%) aimed at fast fluid replacement or a concentrated CHO drink (15%) aimed at CHO provision. In this study we clearly observed that a 2% drink was most effective in delaying the onset of fatigue during prolonged exercise at 30°C but a 15% drink was also effective at delaying fatigue when compared with no fluid. The results of the studies performed in this series have implications for the optimisation of exercise performance in different environmental conditions and indicate that a drink with low CHO content and an emphasis on fluid replacement would be preferential in both cold and hot environments.
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Polacheck, William J. (William Joseph). „Mechanotransduction of interstitial fluid stresses and effects on tumor cell migration“. Thesis, Massachusetts Institute of Technology, 2013. http://hdl.handle.net/1721.1/85531.
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Thesis: Ph. D., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2013."September 2013." Cataloged from PDF version of thesis.
Includes bibliographical references (pages 93-106).
Breast cancer incidence in the United States is I in 8, and over 90% of breast cancer related deaths are due to metastases, secondary tumors at a site distant from the primary tumor. Metastasis formation requires carcinoma cells to navigate through the tumor microenvironment and invade the surrounding stroma. Migration is a highly orchestrated process in which cells are guided by both internal signals and signals from the microenvironment. Hence, understanding the mechanisms that guide cell migration in response to various stimuli in the tumor and stromal microenvironments is key to developing therapies that prevent tumor cell migration and render cancer more treatable. Osmotic and hydrostatic pressure gradients within the extracellular matrix (ECM) drive flow of interstitial fluid through the ECM. Elevated osmotic pressure, lymphatic collapse, solid stress, and increased microvascular permeability contribute to elevated interstitial fluid pressure (IFP) during carcinoma progression, and high intratumoral IFP leads to pressure gradients at the tumor margin, which drive fluid flow that emanates from the tumor core to drain in the surrounding stroma. In this thesis, we explore the effect of interstitial flow (IF) on tumor cell migration. We developed a microfluidic platform to apply repeatable, robust IF through tissue constructs consisting of human metastatic breast cancer cells embedded within a 3D collagen type I matrix. We implemented the microfluidic device to validate CCR7-mediated autologous chemotaxis as a mechanism that guides downstream migration in response to IF. However, we identified a separate competing pathway that drives cell migration upstream (rheotaxis). Rheotaxis results from asymmetry in matrix adhesion stress that is required to balance fluid drag imparted by IF on tumor cells. Thus, autologous chemotaxis, mediated by chemical transport, and rheotaxis, mediated by fluid stresses, compete to direct cell migration downstream or upstream in response to IF. Our results provide insight into mechanotransduction in 3D porous media and into the mechanisms by which asymmetries in matrix adhesion tension guide cell migration. Furthermore, our results demonstrate that the consideration of IF is crucial for understanding and treating metastatic disease. Key words: Interstitial flow, mechanotransduction, tumor cell migration, microfluidics.
by William J. Polacheck.
Ph. D.
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Thompson, Thomas L., Michael A. Maurer und Tom L. Weinert. „Effects of fluid nitrogen fertigation and rate on microsprinkler irrigated grapefruit“. College of Agriculture, University of Arizona (Tucson, AZ), 1999. http://hdl.handle.net/10150/222515.
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Microsprinkler irrigation offers excellent flexibility for site-specific management of water and nitrogen inputs for citrus orchards in the southwestern United States. Escalating water costs, declining water availability, and increasing regulation of nitrogen (N) fertilizer use are causing growers to adopt practices to improve water and N use efficiency. A three-year field experiment was initiated in the spring of 1996 on six-year-old pink grapefruit trees at the University of Arizona Citrus Agricultural Center. The objectives of this experiment are to i) evaluate the effects of fertigation frequency and fluid N application rate on the yield and fruit quality of microsprinkler irrigated grapefruit, and ii) develop best management guidelines for fluid N application frequency and rate for microsprinkler irrigated citrus. Treatments include a factorial combination of two N rates (recommended and 2 the recommended rate) and three fertigation frequencies (weekly, monthly, and tri-monthly). Minimal treatment effects were observed during the first season due to the influence of previous management practices. During the second season, fertilized trees yielded greater than the control trees. There was no significant difference between N rates, but fruit yield was generally higher with monthly or weekly fertigation. Leaf tissue samples collected during the second and third growing seasons showed increasing leaf N with increasing fertigation frequency at the high N rate.
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Tattersall, P. „Evaluation and reduction of numerical diffusion effects in viscous aerofoil flow calculations“. Thesis, Loughborough University, 1993. https://dspace.lboro.ac.uk/2134/6755.
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The Reynolds-averaged Navier-Stokes (RANS) equations form the most accurate model of viscous flow which can currently be solved computationally on a routine basis for practical engineering problems, given the size and cost of present-day computers. Before RANS solution methods can be used with confidence for the design of aircraft components, a number of areas related to solution accuracy must be investigated, one of which is numerical diffusion. Numerical diffusion, arising from the discrete solution method employed, is necessary to ensure numerical stability, but if too much is included the ability to predict physical phenomena (particularly diffusive ones) accurately can be seriously impaired, with obvious implications for the rational assessmenot f turbulence models. The amount of numerical diffusion in solutions of the RANS equations is evaluated in the present work using two currently popular algorithms, for aerofoil flow test cases. The effect of the numerical diffusion on the prediction of physical processes is investigated, as is the behaviour of the numerical diffusion and corresponding solution when grid quality and algorithm smoothing parameters are varied. Results are presented in two ways, line diagrams giving detailed information along individual grid lines, and contour plots (showing a quantity called the Numerical Diffusion Ratio, NDR) giving overall information on accuracy of the solution throughout the field. The level of numerical diffusion in certain parts of the solution is shown to be unacceptably high in a number of cases. Methods for modifying the NDR are investigated, with the aim of making it suitable for use as a "weighting function" for guiding automatic grid adaptation, to improve solution accuracy. It is shown that some of the modified forms of NDR can be used successfully in this manner. The advantages and disadvantages of using such a solution-accuracy measure (as opposed to the usual solution-activity measures) are discussed and some conclusions and recommendations are made.
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Hausner, Alejo. „Non-linear effects in pulsating pipe flow“. Thesis, McGill University, 1992. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=61228.
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The present thesis considers the phenomenon of flow-rate enhancement of polymer solutions in a pipe due to pulsating pressure gradients. It presents an historical review of the problem. The unexplained experimental dependence of enhancement on pulsation frequency reported by Barnes et al is examined, as are later theoretical attempts to reproduce their results. We find that the results can be reproduced only by omitting the important inertial term. The Modified Moment Method is applied to the problem. The results confirm the predictions of other models. The enhancement is of second order in the pulsation amplitude, exhibits a maximum when the pressure gradient is varied, and declines with increasing pulsation frequency. An expansion in powers of the pulsation amplitude gives a satisfactory approximation. Less power is consumed at the same rate of flow if the pressure gradient is constant and not pulsated.
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Schoemaker, André. „The effects of condensation on heat transfer in a preheater“. Thesis, Umeå universitet, Institutionen för fysik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-172919.
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Mare, Chris. „Effects of stratification on flow and dispersion around obstacles in turbulent boundary layers“. Thesis, University of Surrey, 2003. http://epubs.surrey.ac.uk/844132/.
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The effects of stability on the flow and dispersion downstream of a simple obstacle were studied experimentally. Experiments were conducted in the EnFlo atmospheric wind tunnel, where a stably stratified boundary layer is set up by heating the inlet air and cooling the floor of the wind tunnel. Neutral and stable boundary layers with different measures of stability have been successfully modelled and their measured characteristics are reported. The majority of the experiments were then conducted with a neutral boundary layer with a nominal freestream velocity of 2.5 m/s, and two stable boundary layers with nominal freestream velocities of 1.3 m/s and 1.1 m/s. The obstacle used throughout was a 100 mm cube, placed normal to the flow direction and at 45° to the flow direction. A pressure tapped version of the cube was placed in the neutral and stably stratified boundary layers and the pressure distribution was measured on the surface of the cube for each case. Flow measurements were also made in the wake of the cube for the neutral and two stable boundary layers. Concentration measurements were made for different release locations and the flow configurations described above. The source was placed at the leading edge, and source heights at ground level, equal to the obstacle height, and 50% higher than the obstacle height were used. The results and statistics reported here are vertical profiles of concentration, concentration fluctuations and concentration flux, vertical and horizontal plume spread, centreline ground level concentrations and probability distributions. A simple three dimensional wake theory typically used in dispersion modelling was evaluated and the assumptions associated with it reviewed. A Gaussian dispersion model incorporating a building effects model based on the wake theory was then implemented in a computer program. Comparisons were made between the measured and the modelled ground level concentrations. The building effects modelling was then isolated by using the experimental undisturbed plume spread results in the model.
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Williston, William C. „Rotordynamic effects driven by fluid forces from a geometrically imperfect labyrinth seal“. Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1993. http://handle.dtic.mil/100.2/ADA276424.
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Hu, Jin. „Experimental and theoretical investigation of roughness effects on thin laminar fluid films“. Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp02/NQ27957.pdf.
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姚元慶 und Yuanqing Yao. „The effects of human oviductal cells and follicular fluid on sperm functions“. Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1998. http://hub.hku.hk/bib/B31239614.
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Davis, F. H. „Mechanical effects of fluid pressure on the rate of fatigue crack growth“. Thesis, University of Bristol, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.381377.
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Frettsome, Rebecca Louise. „The effects of the human cocyte vestments and follicular fluid on spermatozoa“. Thesis, University of Birmingham, 2012. http://etheses.bham.ac.uk//id/eprint/3512/.
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Our knowledge of the released human ovulatory components, the cumulus-oocyte complex (COC) and follicular fluid, and their physiological effects on spermatozoa and roles in fertilisation remain poorly characterised. The aim of this study was to use a multi-pronged approach to begin to unravel these interactions and their relation to fertilisation success. Experiments designed to better replicate the physiological environment of the female tract showed environmental modulation of sperm motility. Mean sperm velocity values VSL, VAP and VCL increased by 12.4%, 15%, 16.5% respectively, when exposed to cumulus cells from pregnancy-positive donors, compared to pregnancy-negative donors. Follicular fluid elicited a [Ca2+]i response in spermatozoa that was independent of treatment outcome. The response of spermatozoa exposed to follicular fluid at a 50% (v/v) dilution was a large spike on the front of the ‘classical’ progesterone transient response, which has not been previously reported. Human sperm-zona binding (SZB) studies are hampered by the shortage of oocytes, and thus zona pellucida (ZP) available for research. As a possible source of ZP this study investigates the development of an in vitro model for oogenesis, utilising follicular fluid and cumulus cell co-culture with human embryonic stem cells. The feasibility of SPR technology, using both native and recombinant sources of ZP, to measure SZB and identify possible binding candidates is also assessed. The data in this study addresses just some of the potential effects of the COC and follicular fluid on spermatozoa. Further developments within this area may lead to better diagnostics and treatments for patients undergoing ART, in addition to providing targets for novel contraceptives.
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Obligado, Martín. „Fluid-particle interactions : from the simple pendulum to collective effects in turbulence“. Thesis, Grenoble, 2013. http://www.theses.fr/2013GRENI108/document.
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Cette thèse est organisée en deux parties. Après une brève introduction théorique (chapitre 1) et une discussion présentant la soufflerie du LEGI et des techniques expérimentales utilisées (chapitre 2), une première partie étudie les effets individuels des particules dans les écoulements tantôt laminaires et turbulents. Dans une seconde partie je me suis intéressé aux effets collectifs d’une population dense d’inclusions en interaction avec un champ turbulent.Dans le chapitre 3, nous montrons que l’équilibre d’un disque pendulaire faisant face à un écoulement présentant une vitesse moyenne présente un comportement bi-stable et hystérétique. Nous donnons une interprétation simple de ce comportement en termes d’une description par deux puits de potentiel, nécessitant uniquement de connaître la dépendance angulaire du coefficient de trainée normale d’une plaque statique inclinée. Nous étudions l’influence de la turbulence sur l’équilibre du pendule en général et sur la bi-stabilité observée en particulier.La dynamique des objets tractés dans un environnement fluide est d’intérêt pour de nombreuses situations pratiques. Les chapitres 4,5 et 6 concernent l’étude expérimentale de l’équilibre et de la stabilité de la trajectoire d’une sphère tractée à vitesse constante. Dans le chapitre 4, nous avons vu que le sillage d'une sphère peut produire un mouvement hélicoïdal d'une sphère remorqué par un fil. Nous avons constaté qu'il existe un nombre de Reynolds (défini avec le diamètre de la particule et la vitesse moyenne de l’écoulement) particulier pour activer cette motion instable. Une trajectoire en trois dimensions est reconstruite avec un dispositif expérimental extrêmement simple, utilisé pour la caractérisation de la forme de la trajectoire des particules. Dans le chapitre 5, nous étudions expérimentalement l'équilibre et la stabilité de la trajectoire d'une sphère remorqué à une vitesse constante dans la avec un rapport longueur - diamètre sans précédent. En ce chapitre, nous étudions les instabilités développées dans le fil pour un écoulement laminaire. Diffèrent types d’instabilités ont été trouvés dans cette expérience. Dans le chapitre 6, le même système est étudié, mais l'écoulement environnant est turbulent. Nous nous concentrons sur la comparaison entre la dynamique turbulente de la sphère tractée et d’une sphère librement advectèe. Nos résultats sont en accord avec un scénario de filtrage résultant du temps de réponse visqueuse d'une particule d'inertie dont la dynamique est couplée au fluide environnant par la force de traînée. Une caractéristique frappante des écoulements turbulents chargés de particules inertielles est la concentration préférentielle qui conduit à de très fortes hétérogénéités du champ de concentration en particules à différentes échelles. Les diagrammes de Voronoi ont été utilisés pour caractériser quantifier ce phénomène.En ce qui concerne les effets collectifs, trois écoulements différents ont été étudiés : bulles d’air (particules moins denses que le fluide, avec une taille de l’ordre de l´échelle de Kolmogorov) dans un canal a eau (chapitre 7), des particules solides légèrement plus denses que le fluide et diamètre supérieur à l´échelle de Kolmogorov dans une écoulement de von Kármán (chapitre 8) et gouttelettes d’eau dans la soufflerie (chapitre 9) ; de particules beaucoup plus denses que le fluide et diamètre inférieur à l’échelle de Kolmogorov. Enfin, nous proposons une nouvelle méthode de reconstruction des champs de concentration des particules dans les expériences par analogie avec le fonctionnement des caméras linéaire, et en exploitant l’hypothèse de Taylor dans la soufflerie. Cette nouvelle approche nous permet de reconstruire des champs de particules de plusieurs mètres de long. Ces champs permettent d’analyser la formation des superclusters. Nous montrons en effet que les clusters tendent eux-mêmes à s’organiser en superclusters (amas d’amas)This PhD thesis covers many features of fluid-particle interactions, ranging from a simple pendulum inmersed in a flow to the presence of superclusters of water droplets in a wind tunnel.The simplest case studied was a pendulum with a pendulum-blob facing the wind in the wind-tunnel. As the pendulum-blob was a plate, the aerodynamic coefficients as a function of the angle between the plate and the streamwise velocity present a non-trivial behavior, resulting in an hysteresis cycle. We also investigate the influence of turbulence on the equilibrium of the pendulum in general and on the observed bi-stability in particular.Then, different instabilities of towed systems has been studied. In chapter 4 we have seen that the wake of a sphere can produce helicoidal motion of a sphere towed by a wire. We found that there exists a particle Reynolds number Rep threshold for activating this unstable motion. A three-dimensional trajectory was reconstructed with an extremely simple experimental setup, used for characterizing the shape of particle's trajectory. In chapter 5 we investigate experimentally the equilibrium and the stability of the trajectory of a sphere towed at constant velocity in the wind tunnel at the tip of a cable with unprecedented large length-to-diameter aspect ratio. In thist chapter we study the instabilities developped in the wire for a laminar flow.Flutter and divergence instabilities has been found in this experiment.In chapter 6 the same system is studied, but the surrounding flow is turbulent. In this chapter we focus on a comparison with this towed system with freely advected particles in turbulence. Our results are consistent with a filtering scenario resulting from the viscous response time of an inertial particle whose dynamics is coupled to the surrounding fluid via the dragforce.Therefore, depending on several parameters such as the Reynolds number of the particle, the wire or the fluctuations level of the flow, a whole family of instabilities can appear, with no trivial dependencies and important consequences considering different applications of such systems.Concerning the collective effects, three different flows have been studied: a water tunnel, a von Karman flow and a wind tunnel. A broad range of Reynolds numbers, dissipation scales and particles diameters and densities has been covered. Using Voronoi diagrams, we have quantified preferential concentration as a function of the Stokes number and the Reynolds number. In chapter 7 and 8 simultaneous PIV measurements complemented the inertial particles acquisitions. The goal was to analyze if the particles tend to stick into special regions of the flow.In the last chapter also DNS have been performed for comparing with experimental results. A sweep-stick mechanism, in which inertial particles tend to have the same statistics as zero-acceleration points has been proved to be consistent with our results.Finally, a promising new technique has been presented. Based on the standard measurements, a spatial field has been reconstructed allowing us to acquire a several meters long image of particles. The enormous amount of structures present in the image has evidenced that the clusters are grouped at the same time in bigger clusters (i.e. clusters form clusters, that we call superclusters). This new result is still being studied and presents a new and fascinating field for studying particle-flow interactions
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Tanugula, Rohit. „Effects of baffles on damping lateral fluid sloshing oscillations in tanker trucks“. Morgantown, W. Va. : [West Virginia University Libraries], 2001. http://etd.wvu.edu/templates/showETD.cfm?recnum=2112.
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Thesis (M.S.)--West Virginia University, 2001.Title from document title page. Document formatted into pages; contains xiv, 97 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 90-92).
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Yao, Yuanqing. „The effects of human oviductal cells and follicular fluid on sperm functions /“. Hong Kong : University of Hong Kong, 1998. http://sunzi.lib.hku.hk/hkuto/record.jsp?B20868212.
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Cao, Teng. „Pulsating flow effects on turbocharger turbine performance“. Thesis, University of Cambridge, 2015. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.708901.
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