Dissertations / Theses on the topic 'Fluid-structural'
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Yuan, Zhi. "Fluid Modeling with Stochastic and Structural Features." Kent State University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=kent1372898089.
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Lea, Patrick D. "Fluid Structure Interaction with Applications in Structural Failure." Thesis, Northwestern University, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=3605735.
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Methods for modeling structural failure with applications for fluid structure interaction (FSI) are developed in this work. Fracture as structural failure is modeled in this work by both the extended finite element method (XFEM) and element deletion. Both of these methods are used in simulations coupled with fluids modeled by computational fluid dynamics (CFD). The methods presented here allow the fluid to pass through the fractured areas of the structure without any prior knowledge of where fracture will occur. Fracture modeled by XFEM is compared to an experimental result as well as a test problem for two phase coupling. The element deletion results are compared with an XFEM test problem, showing the differences and similarities between the two methods.
A new method for modeling fracture is also proposed in this work. The new method combines XFEM and element deletion to provide a robust implementation of fracture modeling. This method integrates well into legacy codes that currently have element deletion functionality. The implementation allows for application by a wide variety of users that are familiar with element deletion in current analysis tools. The combined method can also be used in conjunction with the work done on fracture coupled with fluids, discussed in this work.
Structural failure via buckling is also examined in an FSI framework. A new algorithm is produced to allow for structural subcycling during the collapse of a pipe subjected to a hydrostatic load. The responses of both the structure and the fluid are compared to a non-subcycling case to determine the accuracy of the new algorithm.
Overall this work looks at multiple forms of structural failure induced by fluids modeled by CFD. The work extends what is currently possible in FSI simulations.
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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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Chow, Yi-Mei Maria 1974. "Computational fluid dynamics for high performance structural facilities." Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/50366.
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Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 1998.Includes bibliographical references (leaves 104-106).
by Yi-Mei Maria Chow.
M.Eng.
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Govindarajan, Vijay. "Three dimensional fluid structural interaction of tissue valves." Diss., University of Iowa, 2013. https://ir.uiowa.edu/etd/2508.
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This thesis presents a stable fluid structural interaction technique to simulate the dynamics of tissue valves including bio-prosthetic heart valves and natural heart valves under physiological Reynolds numbers. A partitioned approach is implemented where the equations governing the flow and the displacement of the structure are solved using two distinct solvers. A FEAP based solid solver is strongly coupled to the p-ELAFINT flow solver using subiteration procedure. The flow solver has been massively parallelized so that the domain can be distributed among several processors. The fixed Cartesian method with adaptive mesh refinement in p-ELAFINT enables us to perform fast and efficient flow computations of problem involving moving boundaries such as heart valve leaflets. To capture the structure deformation, Enhanced Assumed Solid shell element has been implemented into the solid solver which is known for its locking free and superior bending characteristics. Aitken Relaxation method which dynamically computes the relaxation parameter is used for relaxing the solid displacement in the FSI coupling. This helps the subiteration procedure to achieve a faster convergence compared to traditional Subiterative procedures with fixed relaxation parameter. Fung type material model with experimentally derived parameters is used as the constitutive model to capture the realistic solid deformation.
Opening phase of a bicuspid aortic valve (BAV) model derived from a patient specific data and a pericardial bioprosthetic valve model were simulated using the FSI algorithm with realistic material parameters under physiological flow conditions. It was observed that the valves attained its fully open position under 35 milliseconds which is similar to the physiological opening. The bioprosthetic valve attained a fully circular orifice while the BAV attained an ellipsoidal shaped orifice at its fully open position. In the BAV, strong vortical patterns were observed at peak systole and recirculation zones were observed near the sino-tubular junction. The work presented in this thesis be seen as a platform from which complex patient specific data can be modeled under physiological conditions and as a base to include contact mechanics with which complete cardiac cycle can be simulated.
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LeVett, Marshall Allan. "Parallel Time-Marching for Fluid-Thermal-Structural Interactions." The Ohio State University, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=osu1452178897.
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Rathnasingham, Ruben. "Coupled fluid-structural characteristics of actuators for flow control." Thesis, Massachusetts Institute of Technology, 1995. http://hdl.handle.net/1721.1/11142.
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Gallagher, Timothy. "Towards multi-scale reacting fluid-structure interaction: micro-scale structural modeling." Thesis, Georgia Institute of Technology, 2015. http://hdl.handle.net/1853/53483.
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The fluid-structure interaction of reacting materials requires computational models capable of resolving the wide range of scales present in both the condensed phase energetic materials and the turbulent reacting gas phase. This effort is focused on the development of a micro-scale structural model designed to simulate heterogeneous energetic materials used for solid propellants and explosives. These two applications require a model that can track moving surfaces as the material burns, handle spontaneous formation of discontinuities such as cracks, model viscoelastic and viscoplastic materials, include finite-rate kinetics, and resolve both micro-scale features and macro-scale trends. Although a large set of computational models is applied to energetic materials, none meet all of these criteria. The Micro-Scale Dynamical Model serves as the basis for this work. The model is extended to add the capabilities required for energetic materials. Heterogeneous solid propellant burning simulations match experimental burn rate data and descriptions of material surface. Simulations of realistic heterogeneous plastic-bound explosives undergoing impact predict the formation of regions of localized heating called hotspots which may lead to detonation in the material. The location and intensity of these hotspots is found to vary with the material properties of the energetic crystal and binder and with the impact velocity. A statistical model of the hotspot peak temperatures for two frequently used energetic crystals indicates a linear relationship between the hotspot intensity and the impact velocity. This statistical model may be used to generate hotspot fields in macro-scale simulations incapable of resolving the micro-scale heating that occurs in heterogeneous explosives.
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Ciero, Mark K. (Mark Keith). "Design of a fluid elastic actuator with application to structural control." Thesis, Massachusetts Institute of Technology, 1993. http://hdl.handle.net/1721.1/49904.
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Rugonyi, Sandra 1970. "A simultaneous solution procedure for fully coupled fluid flows with structural interactions." Thesis, Massachusetts Institute of Technology, 1999. http://hdl.handle.net/1721.1/80022.
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Lee, June. "Hydro-impact, fluid-structure interaction and structural response of modern racing yacht." Thesis, University of Southampton, 2009. https://eprints.soton.ac.uk/142787/.
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In recent years, faster, lighter and bigger are the key issues in a modern racing yacht for extreme performance. As a result, many yachts have experienced various structural failures caused by the hydrodynamic impact or ’hydro-impact’ phenomenon by slamming. The structural failure by hydro-impact originates from the facts that the external hydro-impact load and fluid structure interaction effect is somewhat misled and when applying the load into current structural design, the ’dynamic’ load is typically, manipulated in a ’static’ way with fluid structure interaction effect, generally, ignored. In this thesis, the hydro-impact load by slamming, its fluid structure interaction effect and dynamic response of the local structure of the yacht are studied. Firstly, to acquire insight into the hydro-impact phenomenon, a series of drop tests and seakeeping-slamming tests are carried out with various sensing instruments of pressure transducers, accelerometer and ’slam patch system’ - a specific application form of generally known pressure panel - are installed. The slam patch system is designed and implemented to investigate the hydro-impact loads and fluid structure interaction effect of slamming. Afterward, the measured hydro-impact loads are summarised via statistical manipulations with regard to pressure and duration time. Secondly, impact pressure by the rules and regulations of various organisations are provided to compare it with the experimental results and structural response calculations. The applicability of the rules and regulations on the high performance racing yacht is also pointed out. Finally, the manipulated loads are used as input data to simulate the transient response of local structure of the yacht structure. Throughout this study, the dynamic and fluid structure interaction effect by hydroimpact phenomenon on local composite structure can be easily visualised and calculated in a conservative way through conventional finite element analysis work.
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Culler, Adam John. "Coupled Fluid-Thermal-Structural Modeling and Analysis of Hypersonic Flight Vehicle Structures." The Ohio State University, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=osu1280930589.
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Miller, Brent Adam. "Loosely Coupled Time Integration of Fluid-Thermal-Structural Interactions in Hypersonic Flows." The Ohio State University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=osu1429828070.
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Chan, Weng Yew, and chanwengyew@gmail com. "Simulation of arterial stenosis incorporating fluid-structural interaction and non-Newtonian blood flow." RMIT University. Aerospace, Mechanical and Manufacturing Engineering, 2006. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20070108.164458.
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The aim of this study is to investigate the fluid-structural response to pulsatile Newtonian and non-Newtonian blood flow through an axisymmetric stenosed vessel using FLOTRAN and ANSYS. This is to provide a basic understanding of atherosclerosis. The flow was set to be laminar and follows a sinusoidal waveform. The solid model was set to have isotropic elastic properties. The Fluid-Structural Interaction (FSI) coupling was two-way and iterative. Rigid and Newtonian cases were investigated to provide an understanding on the effects of incorporating FSI into the model. The wall expansion was found to decrease the axial velocity and increase the recirculation effects of the flow. To validate the models and methods used, the results were compared with the study by Lee and Xu [2002] and Ohja et al [1989]. Close comparisons were achieved, suggesting the models used were valid. Two non-Newtonian models were investigated with FSI: Carreau and Power Law models. The Carreau model fluid behaviour was very close to the Newtonian model. The Power Law model produced significant difference in viscosity, velocity and wall shear stress distributions. Pressure distribution for all models was similar. In order to quantify the changes, Importance Factor (IG) was introduced to determine the overall non-Newtonian effects at two regions: the entire flow model and about the vessel wall. The Carreau model showed reasonable values of IG whereas the Power Law model showed excessive values. Transient and geometrical effects were found to affect the Importance Factor. The stress distributions for all models were found to be similar. Highest stress occurred at the shoulders of the stenosis where a stress concentration occurred due to sharp corners of the geometry and large bending moments. The highest stresses were in the axial direction. Notable circumferential stress was found at the ends of the vessel. Carreau model produced slightly higher stresses than the other models. Wall stresses were found to be primarily influenced by internal pressure, rather than wall shear stresses.
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Younis, Hesham F. (Hesham Farouk). "Fluid and structural modeling of the disease-free and atherosclerotic human carotid bifurcation." Thesis, Massachusetts Institute of Technology, 2002. http://hdl.handle.net/1721.1/8335.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2002.Includes bibliographical references.
Cardiovascular disease is the leading cause of death in the United States. It claims more lives each year than the next 7 leading causes of death combined. Atherosclerosis is a major cause of cardiovascular disease and is an inflammatory process characterized by intimal thickening of arteries and plaque build up. Atherosclerosis can also damage the arterial wall and in turn cause the formation of a thrombus that can partially or totally occlude the diseased artery. If the actual vessel is the carotid artery, this often leads to a stroke. The focus of this study is to analyze the blood flow and arterial wall motion in the carotid bifurcation, a frequently diseased site of the cerebral circulation. Using ultrasound velocity measurements and magnetic resonance imaging (MRI) data of normal volunteers and patients in vivo, realistic blood velocity profiles and wall anatomy geometries are generated and imported into a commercial finite element package, ADINA (Automatic Dynamic Incremental Nonlinear Analysis, Watertown, MA) for computational analysis. Using three types of 3D transient finite element analyses: structure only, rigid walled fluid only and fully coupled fluid-structure interaction, areas of low fluid shear stress and high mechanical strain are identified. These results are compared with experimental evidence collected from the literature as well as histological data of plaque gathered from imaged patients after endarterectomy to identify potential correlations with regions of inflammation.
(cont.) In normal volunteers, localized high cyclic strains (which have been implicated in the stimulation of endothelial and smooth muscle cells) and high maximum wall shear stress temporal gradients (which are related to the expression of atherogenesis-related genes in endothelial cells) are observed at the flow divider and along the outside wall of the external carotid, both common sites of early inflammation. Localized separated flow regions are observed, especially near the outer wall of the internal carotid (the carotid bulb), in response to the localized abrupt changes in the curvature and cross-sectional area of the artery wall. The oscillation and low mean value of wall shear stress in these regions have been widely correlated to atherogenesis and late stage atherosclerotic inflammation. Within the 4 patients studied (P1, P2, P3 and P4), the results indicate that strong correlations exist in the vicinity of the carotid bulb, immediately downstream of observed stenoses, although the sign of the correlation coefficient seems to depend on the severity of the stenosis. The results in the two patients (P1 and P2) with non-constricting ( < 50%) stenoses, show that the wall shear stress (oscillatory shear index) in P1 at that location generally observes strong negative (positive) correlations with smooth muscle cell (SMC), lipid and collagen presence, but no correlation to macrophage presence and vice versa in P2, which experiences solely strong correlations with macrophage presence. This is evidence that the inflammatory process, is continuing downstream of the stenosis ...
by Hesham F. Younis.
Ph.D.
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Boucher, Kaleb S. "The structural and fluid evolution of the Efemçukuru epithermal gold deposit, western Turkey." Thesis, University of British Columbia, 2016. http://hdl.handle.net/2429/58337.
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The Western Tethyan Metallogenic Belt in Turkey hosts numerous hydrothermal mineral deposits. The Efemçukuru epithermal gold deposit, southwest of Izmir contains a resource of 1.69 Moz Au (at 8.39 g/t) and comprises two mineralized NW-trending quartz-rhodochrosite veins (Kestanebeleni and Kokarpınar). These structures are hosted in carbonate-rich phyllites of the Bornova Flysch; an Upper Cretaceous ophiolitic mélange sequence. The veins are pre-dated by similarly striking rhyolite dikes, and a 200 to 500 m wide halo of silicification and chloritization.
Six main stages of veining were identified based on mineralogy, textures, and crosscutting relationships. Early veins of quartz, chlorite, and calc-silicates (Stage I) are cut by two stages of brecciating and banded veins of quartz, rhodochrosite, rhodonite, and pyrite (II, III). Later veins with disseminated (IV) and massive base-metal sulfides (V) cut previous phases, and subsequently by late quartz-carbonate veinlets (VI). Gold occurs as electrum and with pyrite and galena in Stages III, IV, and V. Kestanebeleni and Kokarpınar veins are controlled by moderately to steeply dipping NW- to NNW-trending faults. An analysis of the fault patterns, vein and dike orientations, combined with rock and soil geochemistry indicate that the highest and most prolific gold grades are associated with the steeply dipping NNW-trending structures. These vein segments are dominated by the vein stages of IV and V and represent “fault-linkage zones” where hydrothermal fluids were focused. Carbon and oxygen isotope analysis of vein carbonates indicate a mixed meteoric and magmatic source for the hydrothermal fluids. Variations in δ¹³C and δ¹⁸O values reveal two trends; one corresponding to interaction of meteoric fluids with host rocks (Trend 1), and the second from strong degassing (i.e. boiling) of magmatic fluids (Trend 2). Trend 1 samples are common in both Kestanebeleni and Kokarpınar, while Trend 2 samples occur as localized segments in Kestanebeleni. The latter also correspond to the thickest and highest gold grade regions of Kestanebeleni, indicating degassing was an important process for high grade gold deposition. The fault linkage zones provided the structural permeability that facilitated rapid degassing of auriferous fluids from Stages IV and V.Science, Faculty of
Earth, Ocean and Atmospheric Sciences, Department of
Graduate
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Northrup, Clyde John. "Thermal, chemical, and structural characteristics of fluid migration and fluid-rock interaction in a mid-Proterozoic shear zone, Manzano Mountains, New Mexico." Thesis, The University of Arizona, 1991. http://hdl.handle.net/10150/144646.
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The structure in the study area is dominated by a large, mid-Proterozoic shear zone that strikes NE and dips steeply SE. The zone had a NW directed tectonic transport direction during the shearing. Hydrothermal veining developed at several stages in the deformational history. Early fluids were relatively low in salinity and CO$\sb2$ content and flowed through the rock in small, pervasive structural sites produced by ductile deformation. Fluids migrating through the shear zone at progressively later times tended to be more focused along larger more brittle structures, and had higher salinity and CO$\sb2$ contents. The earliest veins show little alteration of the host rocks while progressively later veins show increasing amounts of wall rock alteration. Alteration near early veins is broadly characterized by increased Fe, Mg, Ca, and Al and decreased Si and K; later veins have increased Si and K, manifested by silicification, sericitization, +/$-$ sulfidization of the host rocks.
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Rydeblad, Elin. "Structural analysis of the hinge region of the Islay Anticline." Thesis, Stockholms universitet, Institutionen för geologiska vetenskaper, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-126006.
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The hinge region of a major anticlinal fold structure in the SW Scottish Highlands was located in the eastern part of the Isle of Islay. The structure plunges gently NNW, with the hinge line measuring 02/026. The hinge region was located by mapping a 2km2 area comprised of deformed Neoproterozoic metasedimentary and metacarbonate rocks, and plotting the measurements on stereograms. The data collected was also analysed to attempt to asses evidence of refolding, and it is suggested in this thesis that the area displays evidence of at least one subsequent refolding event.
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Kendall, Peter K. "Numerical study of effects of fluid-structure interaction on dynamic responses of composite plates." Thesis, Monterey, California : Naval Postgraduate School, 2009. http://edocs.nps.edu/npspubs/scholarly/theses/2009/Sep/09Sep%5FKendall.pdf.
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Thesis (M.S. in Mechanical Engineering)--Naval Postgraduate School, September 2009.Thesis Advisor(s): Kwon, Young W. "September 2009." Description based on title screen as viewed on 6 November 2009. Author(s) subject terms: Fluid-structure interaction, composite, carbon fiber composite, dynamic response, finite element. Includes bibliographical references (p. 95-96). Also available in print.
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Zheng, LiangKan 1972. "Fluid-structure coupling for aeroelastic computations in the time domain using low fidelity structural models." Thesis, McGill University, 2005. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=99127.
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Flutter analysis plays an important role in the design and development of aircraft wings because of the information it provides regarding the flight envelope of the aircraft. With the coupling of the flow and structural solver, the flutter boundary of wings can be evaluated in the time domain. This study: First, computes the aeroelastic response for a typical sweptback wing section model by coupling a flow solver and a two degree of freedom structural equation of motion solver to predict the flutter boundary of an airfoil at different Mach numbers. The results agree well with previous numerical results, and the transonic-dip phenomenon can be observed. Second, a new coupling approach is introduced to conservatively transfer the load and displacement between the flow solver and the structural solver for 3-D flow. By coupling the flow solver and a low fidelity finite element structural model, the flutter point of AGARD wing 445.6 at Mach number 0.499 is computed. The flutter point agrees well with experimental results and previous numerical results.
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Sarwade, Rohit Foster Winfred A. "Life prediction analysis of a subscale rocket engine combustor using a fluid-thermal-structural model." Auburn, Ala., 2006. http://repo.lib.auburn.edu/2006%20Spring/master's/SARWADE_ROHIT_49.pdf.
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Ding, Jie. "Structural and fluid analysis for large scale PEPA models, with applications to content adaptation systems." Thesis, University of Edinburgh, 2010. http://hdl.handle.net/1842/7975.
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The stochastic process algebra PEPA is a powerful modelling formalism for concurrent systems, which has enjoyed considerable success over the last decade. Such modelling can help designers by allowing aspects of a system which are not readily tested, such as protocol validity and performance, to be analysed before a system is deployed. However, model construction and analysis can be challenged by the size and complexity of large scale systems, which consist of large numbers of components and thus result in state-space explosion problems. Both structural and quantitative analysis of large scale PEPA models suffers from this problem, which has limited wider applications of the PEPA language. This thesis focuses on developing PEPA, to overcome the state-space explosion problem, and make it suitable to validate and evaluate large scale computer and communications systems, in particular a content adaption framework proposed by the Mobile VCE. In this thesis, a new representation scheme for PEPA is proposed to numerically capture the structural and timing information in a model. Through this numerical representation, we have found that there is a Place/Transition structure underlying each PEPA model. Based on this structure and the theories developed for Petri nets, some important techniques for the structural analysis of PEPA have been given. These techniques do not suffer from the state-space explosion problem. They include a new method for deriving and storing the state space and an approach to finding invariants which can be used to reason qualitatively about systems. In particular, a novel deadlock-checking algorithm has been proposed to avoid the state-space explosion problem, which can not only efficiently carry out deadlock-checking for a particular system but can tell when and how a system structure lead to deadlocks. In order to avoid the state-space explosion problem encountered in the quantitative analysis of a large scale PEPA model, a fluid approximation approach has recently been proposed, which results in a set of ordinary differential equations (ODEs) to approximate the underlying CTMC. This thesis presents an improved mapping from PEPA to ODEs based on the numerical representation scheme, which extends the class of PEPA models that can be subjected to fluid approximation. Furthermore, we have established the fundamental characteristics of the derived ODEs, such as the existence, uniqueness, boundedness and nonnegativeness of the solution. The convergence of the solution as time tends to infinity for several classes of PEPA models, has been proved under some mild conditions. For general PEPA models, the convergence is proved under a particular condition, which has been revealed to relate to some famous constants of Markov chains such as the spectral gap and the Log-Sobolev constant. This thesis has established the consistency between the fluid approximation and the underlying CTMCs for PEPA, i.e. the limit of the solution is consistent with the equilibrium probability distribution corresponding to a family of underlying density dependent CTMCs. These developments and investigations for PEPA have been applied to both qualitatively and quantitatively evaluate the large scale content adaptation system proposed by the Mobile VCE. These analyses provide an assessment of the current design and should guide the development of the system and contribute towards efficient working patterns and system optimisation.
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Scott, Brandt E. "Structural Control of Thermal Fluid Circulation and Geochemistry in a Flat-Slab Subduction Zone, Peru." DigitalCommons@USU, 2019. https://digitalcommons.usu.edu/etd/7469.
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Hot spring geochemistry from the Peruvian Andes provide insight on how faults, or fractures in the Earth's crust, are capable of influencing fluid circulation. Faults can either promote or inhibit fluid flow and the goal of this study is test the role of a major fault, such as the Cordillera Blanca detachment, as a channel for transporting deep fluids to the surface. Hot springs are abundant in the Cordillera Blanca and Huayhuash ranges in Peru, and several springs issue along the Cordillera Blanca detachment, making this region an ideal setting for our study. To test the role of the Cordillera Blanca detachment, hot springs were sampled along the trace of the fault (Group 1), the western edge of the Cordillera Blanca (Group 2), the eastern side of the Cordillera Blanca (Group 3), and in the Cordillera Huayhuash (Group 4). Water and dissolved gas samples were collected from a total of 25 springs and then analyzed for an array of geochemical parameters. Distinct fluid chemistries from Groups 1 and 2 suggest that the Cordillera Blanca detachment and adjacent minor faults to the west intersect at depth and provide a preferential flow path for deep fluid circulation. Understanding the influence of faults on fluid flow is essential for many disciplines (e.g. oil exploration, hydrology), and this work demonstrates that fluid geochemistry is an excellent tool for assessing the role of faults on fluid distribution.
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Yarra, Dharani Raja. "Structural, mineralogical and fluid evolution of the Shahumyan intermediate sulphidation vein deposit, Kapan district, Armenia." Thesis, University of British Columbia, 2017. http://hdl.handle.net/2429/62679.
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The full abstract for this thesis is available in the body of the thesis, and will be available when the embargo expires.Science, Faculty of
Earth, Ocean and Atmospheric Sciences, Department of
Graduate
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Hayder, Mir Mohammad Abu 1976. "Cross-flow past oscillating circular cylinders." Thesis, McGill University, 2008. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=115685.
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The cross-flow past a pair of equal-diameter circular cylinders, arranged in a staggered configuration, was investigated experimentally in a closed-circuit water tunnel at Reynolds numbers, based on the mean-flow velocity and the cylinder diameter, within the lower subcritical range. The wake formation process was studied employing dye-injection flow visualization and hot-film measurements. The main emphasis was placed on acquiring a physical understanding of the mechanisms leading to vortex shedding, and particularly on the effect of a forced oscillation transverse to the flow direction of either of the two cylinders. For comparison purposes, investigations were also carried out with both cylinders stationary.Experimental results showed that, for a reasonably large angle of incidence, the flow in the wake of a stationary cylinder pair could be characterized by two distinct periodicities, each of which was dominant on one side of the wake. Furthermore, for lower Reynolds numbers (Re < 1.0x10 4), there was an integral relationship between the two Strouhal numbers, but this integral relationship was no longer maintained for Re > 1.0x10 4. On the other hand, the flow around stationary cylinders for a small angle of incidence was characterized by a single Strouhal number, which remained approximately constant over the entire Reynolds number range.
For all the cylinder configurations investigated the wake flow patterns remained essentially the same as those of the corresponding static cases, when either of the two cylinders was forced to oscillate with a nondimensional forcing frequency less than approximately 0.10. However, beyond this value, the wake underwent considerable modification vis-a-vis when the cylinders were stationary, and the flow pattern within the wake was strongly dependent on the value of the forcing frequency. In particular, there were distinct regions of synchronization between the dominant wake periodicities and the cylinder oscillation; these synchronization regions involved sub- and superharmonics as well as fundamental synchronizations. With either upstream or downstream cylinder oscillation, the wake on the mean-flow side of the downstream cylinder synchronized with the shear layers separated from its outer surface, whereas synchronizations on the mean-flow side of the upstream cylinder were caused by the periodicities formed from the interaction of the other three shear layers.
The flow phenomena associated with the synchronizations were described in detail via flow visualization. The organization of the wake was strongly dependent on whether it was the upstream or downstream cylinder which was oscillating. The synchronized wake on the mean-flow side of the downstream cylinder at both lower and higher oscillation frequencies for upstream cylinder oscillation was observed to form either by the shedding of independent vortices or by the coalescence of two or more vortices. However, for downstream cylinder oscillation, although the synchronizations on this side of the wake at lower oscillation frequencies were caused by the shedding of independent vortices or by the coalescence of vortices, those at higher oscillation frequencies were the consequence of the coalescence of vortices only. For large incidence angles, the number of shear layers separated from the downstream cylinder which interacted with those separated from the upstream cylinder was critical in causing the synchronizations on the mean-flow side of the upstream cylinder.
In most cases, the flow for all the cylinder configurations traversed between the same patterns as those obtained when the cylinders were placed stationary at their minimum and maximum transverse spacings; but there were also some situations where the oscillation of either cylinder pushed the flow outside the regimes associated with the stationary configurations. The synchronization ranges obtained when the upstream or downstream cylinder was oscillating were different from each other, and these ranges were much wider than the corresponding synchronization ranges for a single oscillating cylinder. For two cylinders, an analysis of the fundamental synchronization showed that the frequency range over which this occurred was much broader for upstream cylinder oscillation than for downstream cylinder oscillation. Also, the fundamental synchronization ranges for downstream cylinder oscillation were closer to those for single cylinder oscillation in comparison to those for upstream cylinder oscillation.
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Witeof, Zachary. "Exploratory Study on the Design of Combined Aero-Thermo-Structural Experiments in High Speed Flows." The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1366213825.
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Nüchter, Jens Alexander. "The structural record of mid crustal stress and pore fluid pressure changes related to the earthquake cycle." [S.l.] : [s.n.], 2007. http://deposit.ddb.de/cgi-bin/dokserv?idn=983666849.
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Haggan, Titus. "Paragenesis, fluid flow and structural controls on bitumen vein deposits and bitumen-hosted ore deposits, Andean Cordillera." Thesis, University of Aberdeen, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.395068.
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Three bitumen-hosted ore deposits from Peru, Argentina and Chile are described. These deposits (now abandoned) contain diverse mineral assemblages and were mined for vanadium (Minasragra, Peru), uranium (Cerro Huemul, Argentina) and copper (Copiapó, Chile). Highly integrated geological and geochemical studies have enabled the construction of paragenetic sequences and genetic models for these deposits. The Minasragra deposit was a bitumen-hosted vanadium orebody located within the Central Peruvian Andes. It was characterised by a highly unusual and world-unique mineral assemblage which included the vanadium sulphide mineral, patronite. Paragenesis is divided into four distinct phases and deposit genesis is linked to the extreme alteration of an in situ vanadium and sulphur-rich bitumen vein catalyzed by the intrusion of a high-level dyke suite. Cerro Huemul is a bitumen-hosted sandstone-type U-Cu deposit located within continental facies in the Neuquén Basin. Petrographic studies of bitumens and ore species coupled with fluid inclusion analysis enable reconstruction of fluid flow through this sandstone unit. Mineralization is divided into three paragenetic stages and is integrated into a regional and deposit-specific genetic model for ore deposition. The Copiapó study focuses on an extensive andesite lava horizon of Lower Cretaceous age which contains a diverse suite of copper sulphide minerals in intimate association with solid bitumen. Petrographic studies of ore and bitumen species enable the construction of paragenetic sequence which is divided into three mineralizing stages. All three bitumen-ore deposits formed due to the presence of solid bitumen and each case study investigates the role that bitumen played in the mineralizing process. Collectively these studies provide detailed insight into mineralization processes at bitumen-hosted ore deposits and highlight the versatility of bitumens to economically-concentrate a wide range of metals and minerals. A synopsis of the formation of all bitumen-type deposits (solid bitumen veins and bitumen-hosted ore bodies) is presented and ideas regarding the potential of mineral exploration for organo-metallic deposits within the Andean Cordillera are outlined.
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Wang, Baoyuan. "Detached-Eddy Simulation of Flow Non-Linearity of Fluid-Structural Interactions using High Order Schemes and Parallel Computation." Scholarly Repository, 2009. http://scholarlyrepository.miami.edu/oa_dissertations/221.
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The objective of this research is to develop an efficient and accurate methodology to resolve flow non-linearity of fluid-structural interaction. To achieve this purpose, a numerical strategy to apply the detached-eddy simulation (DES) with a fully coupled fluid-structural interaction model is established for the first time. The following novel numerical algorithms are also created: a general sub-domain boundary mapping procedure for parallel computation to reduce wall clock simulation time, an efficient and low diffusion E-CUSP (LDE) scheme used as a Riemann solver to resolve discontinuities with minimal numerical dissipation, and an implicit high order accuracy weighted essentially non-oscillatory (WENO) scheme to capture shock waves. The Detached-Eddy Simulation is based on the model proposed by Spalart in 1997. Near solid walls within wall boundary layers, the Reynolds averaged Navier-Stokes (RANS) equations are solved. Outside of the wall boundary layers, the 3D filtered compressible Navier-Stokes equations are solved based on large eddy simulation(LES). The Spalart-Allmaras one equation turbulence model is solved to provide the Reynolds stresses in the RANS region and the subgrid scale stresses in the LES region. An improved 5th order finite differencing weighted essentially non-oscillatory (WENO) scheme with an optimized epsilon value is employed for the inviscid fluxes. The new LDE scheme used with the WENO scheme is able to capture crisp shock profiles and exact contact surfaces. A set of fully conservative 4th order finite central differencing schemes are used for the viscous terms. The 3D Navier-Stokes equations are discretized based on a conservative finite differencing scheme, which is implemented by shifting the solution points half grid interval in each direction on the computational domain. The solution points are hence located in the center of the grid cells in the computational domain (not physical domain). This makes it possible to use the same code structure as a 2nd order finite volume method. A finite differencing high order WENO scheme is used since a finite differencing WENO scheme is much more efficient than a finite volume WENO scheme. The unfactored line Gauss-Seidel relaxation iteration is employed for time marching. For the time accurate unsteady simulation, the temporal terms are discretized using the 2nd order accuracy backward differencing. A pseudo temporal term is introduced for the unsteady calculation following Jameson's method. Within each physical time step, the solution is iterated until converged based on pseudo time step. A general sub-domain boundary mapping procedure is developed for arbitrary topology multi-block structured grids with grid points matched on sub-domain boundaries. The interface of two adjacent blocks is uniquely defined according to each local mesh index system (MIS) which is specified independently. A pack/unpack procedure based on the definition of the interface is developed to exchange the data in a 1D array to minimize data communication. A secure send/receive procedure is employed to remove the possibility of blocked communication and achieve optimum parallel computation efficiency. Two terms, "Order" and "Orientation", are introduced as the logics defining the relationship of adjacent blocks. The domain partitioning treatment of the implicit matrices is to simply discard the corner matrices so that the implicit Gauss-Seidel iteration can be implemented within each subdomain. This general sub-domain boundary mapping procedure is demonstrated to have high scalability. Extensive numerical experiments are conducted to test the performance of the numerical algorithms. The LDE scheme is compared with the Roe scheme for their behavior with RANS simulation. Both the LDE and the Roe scheme can use high CFL numbers and achieve high convergence rates for the algebraic Baldwin-Lomax turbulence model. For the Spalart-Allmaras one equation turbulence model, the extra equation changes the Jacobian of the Roe scheme and weakens the diagonal dominance. It reduces the maximum CFL number permitted by the Roe scheme and hence decreases the convergence rate. The LDE scheme is only slightly affected by the extra equation and maintains high CFL number and convergence rate. The high stability and convergence rate using the Spalart-Allmaras one equation turbulence model is important since the DES uses the same transport equation for the turbulence stresses closure. The RANS simulation with the Spalart-Allmaras one equation turbulence model is the foundation for DES and is hence validated with other transonic flows including a 2D subsonic flat plate turbulent boundary layer, 2D transonic inlet-diffuser, 2D RAE2822 airfoil, 3D ONERA M6 wing, and a 3D transonic duct with shock boundary layer interaction. The predicted results agree very well with the experiments. The RANS code is then further used to study the slot size effect of a co-flow jet (CFJ) airfoil. The DES solver with fully coupled fluid-structural interaction methodology is validated with vortex induced vibration of a cylinder and a transonic forced pitching airfoil. For the cylinder, the laminar Navier-Stokes equations are solved due to the low Reynolds number. The 3D effects are observed in both stationary and oscillating cylinder simulation because of the flow separations behind the cylinder. For the transonic forced pitching airfoil DES computation, there is no flow separation in the flow field. The DES results agree well with the RANS results. These two cases indicate that the DES is more effective on predicting flow separation. The DES code is used to simulate the limited cycle oscillation of NLR7301 airfoil. For the cases computed in this research, the predicted LCO frequency, amplitudes, averaged lift and moment, all agree excellently with the experiment. The solutions appear to have bifurcation and are dependent on the initial perturbation. The developed methodology is able to capture the LCO with very small amplitudes measured in the experiment. This is attributed to the high order low diffusion schemes, fully coupled FSI model, and the turbulence model used. This research appears to be the first time that a numerical simulation of LCO matches the experiment. The DES code is also used to simulate the CFJ airfoil jet mixing at high angle of attack. In conclusion, the numerical strategy of the high order DES with fully coupled FSI model and parallel computing developed in this research is demonstrated to have high accuracy, robustness, and efficiency. Future work to further maturate the methodology is suggested.
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Eastes, Bryan. "Fluid and Crystallized g vs. Multiple Intelligence| A Structural Equation Modeling Study of Human Intelligence Theories & Measurement." Thesis, George Mason University, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=10140345.
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The thesis investigated debated intelligence theories: Cattell’s (1943) “Theory of Fluid and Crystallized Intelligence” and Gardner’s (1983) “Theory of M.I.” The research asks: Which existing theory-based and hypothetically based measurement models of intelligence fit the measurement data better? How does a traditional vs. modified M.I. Theory measurement model fit? How does a combined measurement model of the theories fit? Participants (n=287) were students (age 18-25) from a top-tier East-Coast university. Approximate statistical power is .90 with effect size of .5 (p≤.05). Participants were administered the Reynolds Adaptable Intelligence Test and Multiple Intelligence Developmental Assessment Scales. Structural equation modeling revealed better fit for the “Theory of Fluid and Crystallized Intelligence” data (χ2(4) =8.08, p=.09; CMIN/d.f.=2.02; RMSEA= .06; TLI= .98; CFI= .99; IFI=.99; SRMR=.0221). The traditional Theory of M.I.” model fit was insupportable (χ 2(300) =1441.448, p<.000; CMIN/d.f.=4.80; RMSEA= .12; TLI= .61; CFI= .64; IFI=.65; SRMR=.2239), but alternative M.I. models were supported. A correlated M.I. model (χ2(264) =569.09, p<.001; CMIN/d.f.=2.16; RMSEA= .06; TLI= .88; CFI= .90; IFI= .91; SRMR=.06) and 4-factor model M.I. with distinct bodily-kinesthetic and musical talent (χ2(267) =526.32, p<.001; CMIN/d.f.=2.12; RMSEA= .06; GFI=.91; TLI= .92; CFI= .94; IFI= .94; SRMR=.06) show acceptable to good fit. A M.I. Indicator & R.A.I.T. TII to g SCU Model shows good fit (χ2(120) =247.56, p<.001; CMIN/d.f.=2.06; RMSEA= .06; TLI= .89; GFI=.94; CFI= .96; IFI= .96; SRMR=.10). Current findings are further discussed in relation to analogous studies.
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Almurshedi, Ahmed. "Alternative plate deformation phenomenon for squeeze film levitation." Thesis, Brunel University, 2018. http://bura.brunel.ac.uk/handle/2438/17120.
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This thesis deals with a theoretical and an experimental exploration of squeeze film levitation (SFL) of light objects. The investigations aimed to find the important design parameters controlling this levitation mechanism and also to suggest an alternative way to implement SFL. The study, through computer modelling and experimental validation, focused on Poisson's contraction effect for generating SFL. A finite element model (ANSYS) was verified by experimental testing of five different plate designs. Each plate was subjected to a uniaxial plain stress by an arrangement of two hard piezoelectric actuators (PZT) bonded to the bottom of the plate and driven with DC or AC voltages. It was observed that pulsation of a dimple or crest shaped elastic deformation along the longitudinal axis in the central area of the plate was created because of Poisson's contraction. This Poisson's effect generated the squeeze-film between the plate and the levitated object. The separation distance between a floating lightweight object and the plate was analysed using computational fluid dynamics (ANSYS CFX) through creation of a modelling model for the air-film entrapped between the two interacting surfaces - a typical three-dimensional fluid-solid interaction system (FSI). Additionally, the levitation distance has been experimentally measured by a Laser Sensor. A satisfactory agreement has been found between model predictions and experimental results. Two levitation systems, one based on a horn transducer (Langevin type) and the other one in the form of a plain rectangular plate made of Aluminium and firmly fastened at both ends with a surface-mounted piezoelectric actuator, were compared in this thesis. Both devices were based on SFL mechanism. Evidently, the performances of both designs were greatly influenced by the design structure and in particular by the driving plate characteristics such as plate size and geometry as well as the driving boundary conditions. To this end, physical experiments were carried out and it was found that the device utilising horn-type transducer yields better levitation performance. Ultimately, the research explained the confusion between three approaches to non-contact levitation through literature review and also pointed out some essential parameters like piezoelectric actuators location, material of the driving structure, coupled-field between the actuators and the driving structure and the fluid-solid interface that was existed between the excited plate and the levitated object.
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Lynn, Helen Beatrice. "Structural controls on subsurface fluid migration through thrust sheets of the Stewart Peak culmination, northern Salt River Range, Wyoming." Thesis, Montana State University, 2012. http://etd.lib.montana.edu/etd/2012/lynn/LynnH1212.pdf.
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The Stewart Peak culmination is a duplex fault zone of the Absaroka thrust sheet, which is part of the Sevier fold-and-thrust belt in western Wyoming. Duplex structures can serve as subsurface oil, gas and carbon dioxide (CO â‚‚) traps. The culmination lies east and up-dip from naturally occurring CO â‚‚ traps in Idaho and west of the Moxa arch in Wyoming, another naturally occurring CO â‚‚ trap and potential target for CO â‚‚ sequestration. The culmination has been uplifted and breached by erosion, exposing traps and reservoir rocks analogous to proximal subsurface structures, thus allowing for outcrop-scale investigation of the elements that comprise a complex trap and an analysis of the relative timing of faulting, fracturing, fluid migration and structurally-controlled diagenesis. The purpose of this study was to characterize structural elements of the Stewart Peak culmination that controlled fluid flow. Field-based analyses of fractures, fault damage zones and breccia pipes were conducted in order to assess how these structures affected fluid flow. Rocks were sampled in order to elucidate the diagenetic characteristics of alteration associated with episodes of fluid migration and document the qualities of reservoir rocks. Faulting has led to extensive fracturing and brecciation of rocks in the culmination. The geometry of faults and fracture sets initially controlled fluid migration pathways. Brecciated fault zones of large-displacement thrusts served as focused fluid conduits. Fracturing also facilitated fluid flow, locally enhancing porosity and permeability. The protracted history of deformation in the culmination helped maintain fluid flow pathways through fractures and fault zones. Fault zones and fractures display complex diagenetic alteration as a result of multiple eposodes of deformation and fluid migration. Sub-vertical fracture swarms and breccia bodies dissect some fault zones and represent discrete vertical fluid pathways through which CO â‚‚-charged hydrothermal fluids were focused. Hydrothermal brines may have enhanced structurally-controlled fluid migration pathways through interrelated processes of effervescence-induced brecciation and dolomitization. Faulting, fracturing, brecciation and diagenetic alteration generally enhanced the quality of reservoir rocks and increased the hydraulic connectivity within the culmination. The enhanced porosity and permeability of the Madison Limestone and Bighorn Dolomite indicate that these reservoirs have good potential for CO â‚‚ sequestration.
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Hesseltine, Garth. "Micro- to Macro-Scale Structural and Lithological Architecture of Basal Nonconformities: Implications for Fluid Flow and Injection Induced Seismicity." DigitalCommons@USU, 2019. https://digitalcommons.usu.edu/etd/7497.
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Rising incidents of earthquakes caused by human activity in the United States, known as induced earthquakes, is a growing concern. Induced earthquakes may occur when fluid and/or wastewater is injected several kilometers beneath the Earth’s surface into sedimentary rocks. Fluids and pressures can migrate from the sedimentary rocks, which are typically friendlier to fluid flow, into underlying less friendlier crystalline rocks along fluid pathways weakening and possibly reactivating preexisting faults. Understanding potential fluid pathways and/or barriers from the sedimentary rocks to crystalline rocks is crucial. I investigate the structure, composition, and heterogeneity of rocks near the contact between the sedimentary and crystalline rocks, known as nonconformities, and highlight their possible role in the transmission of fluids and porefluid pressures into the crystalline basement.
To characterize nonconformities, we examined outcrop analogs and drillcore of nonconformities in New Mexico, Colorado, and Michigan. Geochemical, structural, and hydrological techniques were used to analyze the nonconformities at microscopic to megascopic scales. The nonconformities observed in this study consist of variably deformed, weathered, and altered igneous and metamorphic crystalline basement overlain by sedimentary rocks cut by outcrop- and map-scale faults. The nonconformity at the New Mexico sites includes a clay-rich weathered horizon atop deformed and jointed crystalline basement. Heterogeneity observed in the fracture and joint networks within the crystalline basement contributes to permeability heterogeneity and anisotropy. The crystalline basement adjacent to the nonconformity at the Colorado site is relatively fresh and unweathered and overlain by low permeability sandstones. The nonconformity and underlying slates in the Michigan drillcore are overprinted by hydrothermal alteration and carbonate mineralization, which provides evidence of hydrological communication between sedimentary and crystalline rocks. The nonconformities display a range of structural, hydrological, and geochemical styles and characteristics which vary over relatively small spatial extents. The geological and hydrogeological histories and complexities of nonconformity analogs provide valuable information to understand how fluids, past, and present, interact with the contact. This study introduces some of the factors that may control fluid flow adjacent to nonconformities and their possible significance to the interplay of deformation, fluid flow, and induced seismicity.
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Paik, Kwang Jun. "Simulation of fluid-structure interaction for surface ships with linear/nonlinear deformations." Diss., University of Iowa, 2010. https://ir.uiowa.edu/etd/569.
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The present research develops a numerical fluid-structure interaction (FSI) code based on CFDShip-Iowa version 4, a general-purpose URANS/DES overset fluid solver. Linear and nonlinear FSI methods are developed to compute structural responses on surface ships or marine structures. The modal superposition transient analysis and the nonlinear FEM structure solver are used for small and large deformation FSI problems, respectively.
The gluing method is applied to transfer the forces and displacements on non-matching grids for fluid and structure domains. The linear FEM solver is applied to deform the boundary layer grid with large deformation in the fluid domain, while the deformation is ignored in small deformation problems. Deformation of an interior point in the boundary layer grid is obtained using linear interpolation in both linear and nonlinear deformation problems.
The S175 containership is studied in regular waves as an application example for the linear problem. Heave and pitch responses are compared with the experiments, showing good agreement. Time histories of vertical bending moment (VBM) are calculated using rigid model, one-way coupling, and two-way coupling approaches. The elastic models are able to capture the ringing of the VBM induced by slamming, while the rigid model shows a peak at the moment of slamming without further fluctuations. The two-way coupling method shows the effects of hull deformation on the amplitude and phase of VBM as well as the accelerations of heave and pitch.
For the nonlinear deformation problem three sloshing tanks with an elastic bar clamped to its bottom or top are simulated and compared with the experiments and other numerical simulation results. The present simulation results show reasonable agreement with the experiments for bar deformation and free surface elevation. A secondary wave on the free surface is creadted by the vorticity generated from the free surface. The effect of the bar on the sloshing impact is studied comparing dynamic pressure acting on the tank wall without bar, with an elatic bar, and with a rigid bar.
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Thompson, Sally. "Structural and lithological controls upon fluid migration within the Chalk and Upper Greensand aquifers in the Chilterns and Lambourn Downs." Thesis, Royal Holloway, University of London, 2002. http://digirep.rhul.ac.uk/items/36cb9d93-4302-5c6f-cfa5-0306066beff7/1/.
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The influence of lithological heterogeneities, structural discontinuities and discontinuity surface mineralisation upon groundwater migration within the Chalk and the Upper Greensand of southern England has been investigated. Lithological heterogeneities in the Chalk succession include marl seams, hardgrounds, tabular flints and nodular flints. Each of these heterogeneities has a lower intrinsic porosity and permeability than in the calcite rich chalk. The influence that each of these heterogeneities exerts upon groundwater flow is assessed in relation to the porosity and permeability of the Chalk. Clay minerals, iron oxide and dendrites of manganese hydroxide are forms of discontinuity surface mineralisation. The paragenesis of these deposits is predominately from superficial deposits resting on the Chalk. The presence of mineralisation reduces the porosity and permeability of discontinuity surfaces. Mineralisation reduces the exchange between water in discontinuities with that in the matrix. In the matrix, parallel to the discontinuity surface, a zone of enhanced porosity occurs, formed by the dissolution of the Chalk matrix. Parallel to this zone is a zone of reduced porosity which has been formed by the precipitation of calcite as overgrowths upon the matrix. Mineralised discontinuity surfaces provide routes for rapid migration of groundwater in both the saturated and unsaturated zones. There is no discernible relationship between the physical properties of discontinuities (i.e. orientation, dip, dip direction) and the occurrence of mineralisation. The distribution of discontinuities within the Chalk is not uniform. Clusters of similarly orientated discontinuities occur separated by less disturbed material, which causes the Chalk act as an anisotropic aquifer. Solution formed cavities have been observed at the point of intersection between discontinuities, or at the intersection of discontinuities with lithological heterogeneities. The cavities extend laterally along the line of intersection. These cavities allow rapid migration of groundwater within the saturated zone. Inclined solution cavities are formed where the discontinuities have differing orientations or where the lithological heterogeneities are dipping. Such cavities provide preferential routes of groundwater recharge through the unsaturated zone. The Chalk is a less effective aquifer at depth due to the decreased occurrence of solution enhanced discontinuities. The Chalk and Upper Greensand aquifers are not in hydraulic continuity in locations where the basal unit of the Lower Chalk, the Glauconitic Marl is present.
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Samyn, Denis. "Structural and geochimical analysis of basal ice from Taylor Glacier, Antarctica: on role and behaviour of the interstistial fluid phase." Doctoral thesis, Universite Libre de Bruxelles, 2005. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210968.
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Ruan, Xiaoyong. "Structural Integrity Assessment of Nuclear Energy Systems." Kyoto University, 2020. http://hdl.handle.net/2433/253517.
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Wijns, Christopher P. "Exploring conceptual geodynamic models : numerical method and application to tectonics and fluid flow." University of Western Australia. School of Earth and Geographical Sciences, 2005. http://theses.library.uwa.edu.au/adt-WU2005.0068.
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Geodynamic modelling, via computer simulations, offers an easily controllable method for investigating the behaviour of an Earth system and providing feedback to conceptual models of geological evolution. However, most available computer codes have been developed for engineering or hydrological applications, where strains are small and post-failure deformation is not studied. Such codes cannot simultaneously model large deformation and porous fluid flow. To remedy this situation in the face of tectonic modelling, a numerical approach was developed to incorporate porous fluid flow into an existing high-deformation code called Ellipsis. The resulting software, with these twin capabilities, simulates the evolution of highly deformed tectonic regimes where fluid flow is important, such as in mineral provinces. A realistic description of deformation depends on the accurate characterisation of material properties and the laws governing material behaviour. Aside from the development of appropriate physics, it can be a difficult task to find a set of model parameters, including material properties and initial geometries, that can reproduce some conceptual target. In this context, an interactive system for the rapid exploration of model parameter space, and for the evaluation of all model results, replaces the traditional but time-consuming approach of finding a result via trial and error. The visualisation of all solutions in such a search of parameter space, through simple graphical tools, adds a new degree of understanding to the effects of variations in the parameters, the importance of each parameter in controlling a solution, and the degree of coverage of the parameter space. Two final applications of the software code and interactive parameter search illustrate the power of numerical modelling within the feedback loop to field observations. In the first example, vertical rheological contrasts between the upper and lower crust, most easily related to thermal profiles and mineralogy, exert a greater control over the mode of crustal extension than any other parameters. A weak lower crust promotes large fault spacing with high displacements, often overriding initial close fault spacing, to lead eventually to metamorphic core complex formation. In the second case, specifically tied to the history of compressional orogenies in northern Nevada, exploration of model parameters shows that the natural reactivation of early normal faults in the Proterozoic basement, regardless of basement topography or rheological contrasts, would explain the subsequent elevation and gravitationally-induced thrusting of sedimentary layers over the Carlin gold trend, providing pathways and ponding sites for mineral-bearing fluids.
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Dinc, Aysun Nilay [Verfasser]. "Local earthquake tomography of Central America : structural variations and fluid transport in the Nicaragua-Costa Rica subduction zone / Aysun Nilay Dinc." Kiel : Universitätsbibliothek Kiel, 2010. http://d-nb.info/1019951737/34.
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Duschl, Florian [Verfasser], Alfons van den [Akademischer Betreuer] Kerkhof, Martin [Gutachter] Sauter, and Jonas [Gutachter] Kley. "Structural control on fluid migration in inverted sedimentary basins / Florian Duschl ; Gutachter: Martin Sauter, Jonas Kley ; Betreuer: Alfons van den Kerkhof." Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2019. http://d-nb.info/1185168605/34.
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Ebna, Hai Bhuiyan Shameem Mahmood [Verfasser]. "Finite Element Approximation of Ultrasonic Wave Propagation under Fluid-Structure Interaction for Structural Health Monitoring Systems / Bhuiyan Shameem Mahmood Ebna Hai." Hamburg : Helmut-Schmidt-Universität, Bibliothek, 2017. http://d-nb.info/1148436170/34.
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Laukamp, Carsten. "Structural and fluid system evolution in the Otavi Mountainland (Namibia) and its significance for the genesis of sulphide and nonsulphide mineralisation." [S.l. : s.n.], 2006. http://nbn-resolving.de/urn:nbn:de:bsz:16-opus-72259.
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Zhang, Tianqi, and Chetan Bhandare. "Numerical Investigations on theBuckling Characteristics andAnalysis of Deformation andStress of Brush Seals." Thesis, Blekinge Tekniska Högskola, Institutionen för maskinteknik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-15669.
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Brush seals are contact seals which are efficient and reliable and can beused in any rotatory machinery. A theoretical model of a brush seal wassuggested and used for a simulation study. Comparison between the resultsof the experiment and simulation is used to verify the accuracy of model.Following the basic simulation steps, more simulation will be done to geta further analysis. The further analysis will be studied in bristles’ bucklingcharacteristics, deformation and stress. The buckling, stress anddeformation is related to the brush seal’s performance. This work givesthe different geometry of bristle’s effect to its buckling characteristics andthe study of stress and deformation caused by fluid flow across bristlesduring operation.
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Fadipe, Oluwaseun Adejuwon. "Reservoir quality, structural architecture, fluid evolution and their controls on reservoir performance in block 9, F-O gas field, Bredasdorp Basin, offshore South Africa." Thesis, University of the Western Cape, 2012. http://hdl.handle.net/11394/4005.
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Philosophiae Doctor - PhDThe use of integrated approach to evaluate the quality of reservoir rocks is increasingly becoming vital in petroleum geoscience. This approach was employed to unravel the reason for the erratic reservoir quality of sandstones of the F-O gas field with the aim of predicting reservoir quality, evaluate the samples for presence, distribution and character of hydrocarbon inclusions so as to gain a better understanding of the fluid history. Information on the chemical conditions of diagenetic processes is commonly preserved in aqueous and oil fluid inclusion occurring in petroleum reservoir cements. Diagenesis plays a vital role in preserving, creating, or destroying porosity and permeability, while the awareness of the type of trap(s) prior to drilling serves as input for appropriate drilling designs. Thus an in-depth understanding of diagenetic histories and trap mechanisms of potential reservoirs are of paramount interest during exploration stage.This research work focused on the F-O tract located in the eastern part of Block 9 on the north-eastern flank of the Bredasdorp Basin, a sub-basin of Outeniqua Basin on the southern continental shelf, offshore South Africa. The Bredasdorp Basin experienced an onset of rifting during the Middle-Late Jurassic as a result of dextral trans-tensional stress produced by the breakup of Gondwanaland that occurred in the east of the Falkland Plateau and the Mozambique Ridge. This phenomenon initiated a normal faulting, north of the Agulhas-Falkland fracture zone followed by a widespread uplift of major bounding arches within the horst blocks in the region that enhanced an erosion of lower Valanginian drift to onset second order unconformity.This study considered 52 selected reservoir core samples from six wells(F-O1, F-O2, F-O3, F-O4, F-R1 and F-S1) in the F-O field of Bredasdorp Basin with attention on the Valanginian age sandstone. An integrated approach incorporating detailed core descriptions, wireline log analysis (using Interactive petrophysics), structural interpretation from 2D seismic lines (using SMT software) cutting across all the six wells, multi-mineral (thin section, SEM,XRD) analyses, geochemical (immobile fluid and XRF) and fluid inclusion(fluid inclusion petrography and bulk volatile) analyses were deployed for the execution of this study. Core description revealed six facies from the six wells grading from pure shale (Facies 1), through progressively coarsening interbedded sand-shale “heterolithic facies (Facies 2 - 4), to cross bedded and minor massive sandstone (Facies 5 - 6). Sedimentary structures and mineral patches varies from well to well with bioturbation, synaeresis crack, echinoid fragments, fossil burrow, foreset mudrapes, glauconite and siderite as the main observed features. All these indicate that the Valanginian reservoir section in the studied wells was deposited in the upper shallow marine settings. A combination of wireline logs were used to delineate the reservoir zone prior to core description. The principal reservoirs are tight, highly faulted Valanginian shallow-marine sandstones beneath the drift-onset unconformity, 1At1 and were deposited as an extensive sandstone “sheet” within a tidal setting. The top and base of the reservoir are defined by the 13At1 and 1At1 seismic events,respectively. This heterogeneous reservoir sandstones present low-fair porosity of between 2 to 18 % and a low-fair permeability value greater than 0.1 to 10 mD. The evolution of the F-O field was found to be controlled by extensional events owing to series of interpreted listric normal faults and rifting or graben generated possibly by the opening of the Atlantic. The field is on a well-defined structural high at the level of the regional drift-onset unconformity, 1At1.Multi-mineral analysis reveals the presence of quartz and kaolinite as the major porosity and permeability constraint respectively along with micaceous phases. The distribution of quartz and feldspar overgrowth and crystals vary from formation to formation and from bed to bed within the same structure. The increase in temperature that led to kaolinite formation could have triggered the low-porosity observed. Three types of kaolinite were recognized in the sandstone, (1) kaolinite growing in between expanded mica flakes; (2)vermiform kaolinite; and (3) euhedral kaolinite crystals forming matrix.Compositional study of the upper shallow marine sandstones in the Valanginian age indicates that the sandstones are geochemically classified as majorly litharenite having few F-O2 samples as subarkose with all F-O1 samples classified as sub-litharenite sandstone.Most of the studied wells are more of wet gas, characterized by strong response of C2 – C5 with F-O1 well showing more of gas condensate with oil shows (C7 – C11) based on the number of carbon atom present. In some cases,sulphur species (characterized by the presence of H2S, S2, CS2 and SO2) of probably thermal origin were identified while some log signatures revealed aromatic enriched sandstones possibly detecting nearby gas charges. The studied wells in the F-O field, based on fluid inclusion bulk volatile analysis are classified as gas discoveries except for F-O1 with gas condensate and oil shows.The integration of multi-mineral results and fluid inclusion studies show a dead oil stain with no visible liquid petroleum inclusion in the samples indicating the presence of quartz, kaolinite and stylolite as a major poro-perm constraint.
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Bodurtha, Paul. "Novel techniques for investigating the permeation properties of environmentally-friendly paper coatings : the influence of structural anisotropy on fluid permeation in porous media." Thesis, University of Plymouth, 2003. http://hdl.handle.net/10026.1/2049.
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In this study, we have investigated the effects of structural anisotropy of porous media on the permeation of fluids. The motivation for the work was an increased understanding of the permeation of inks into paper coatings, which often contain platey or needle-like particles, which have been aligned during the coating process. However, the findings are also relevant to other systems, such as the sub-terranean migration of fluids, including pollutants, within shale that contains particles of high aspect ratio. Mineral pigments, comprising mainly of calcium carbonate or clay, are often are applied to the surface of paper to improve optical and printing properties. For a high quality image to be achieved, the coating should have sufficient capillarity to allow the ink film to set within the time-scale of a modern printing press. The permeation of fluids into a range of different coating formulations has been investigated, with its main focus on the following samples: Speswhite and Amazon90 SD, which belong to the Kaolin (day) mineral group, and OpacarbA40 and Albaglos, which belong to the Precipitated Calcium Carbonate (PCC) mineral group. The permeation was measured by five different techniques, including a novel use of the Ink Surface Interaction Tester. The results were modelled using a modified version of the software package ‘Pore-Cor’, which simulated both permeability and capillary absorption of a wetting liquid into porous media containing anisotropic voids, and allowed the effects of anisotropy to be isolated from other closely related pore properties. The model generated a simplified three-dimensional void network having pores with a rectangular cross-section and throats with an elliptic cross-section. From visual inspection of the modelled structures, the effect of anisotropy revealed advance wetting in the narrow features of Speswhite-CL and OpacarbA40-CL. Overall, to gain a clear understanding of the permeation of anisotropic structures both inertia and surface throat density is needed to be included in the Pore-Cor model. Once these factors were applied to the model, it was able to predict the permeation of fluids more successfully than those predicted by the Kozeny and aligned cylinders models. The insights gained from this study have allowed conclusions to be drawn about the nature of fluid permeation; they have therefore opened the way to more sophisticated modelling and the engineering of high performance coating structures.
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Rubio, Jose E. "Modal Characterization and Structural Dynamic Response of a Crane Fly Forewing." ScholarWorks@UNO, 2014. http://scholarworks.uno.edu/td/1941.
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This study describes a method for conducting the structural dynamic analysis of a crane fly (family Tipulidae) forewing under different airflow conditions. Wing geometry is captured via micro-computed tomography scanning. A finite element model of the forewing is developed from the reconstructed model of the scan. The finite element model is validated by comparing the natural frequencies of an elliptical membrane with similar dimensions of the crane fly forewing to its analytical solution. Furthermore, a simulation of the fluid-structure interaction of the forewing under different airflows is performed by coupling the finite element model of the wing with a computation fluid dynamics model. From the finite element model, the mode shapes and natural frequencies are investigated; similarly, from the fluid-structure interaction, the time-varying out-of-plane deformation, and the coefficients of drag and lift are determined.
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Lehmann, Lutz. "Wave propagation in infinite domains : with applications to structure interaction /." Berlin [u.a.] : Springer, 2007. http://www.gbv.de/dms/bs/toc/523903820.pdf.
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Ickes, Jacob. "Improved Helicopter Rotor Performance Prediction through Loose and Tight CFD/CSD Coupling." University of Toledo / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1408476196.
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Nasar, Abouzied. "Eulerian and Lagrangian smoothed particle hydrodynamics as models for the interaction of fluids and flexible structures in biomedical flows." Thesis, University of Manchester, 2016. https://www.research.manchester.ac.uk/portal/en/theses/eulerian-and-lagrangian-smoothed-particle-hydrodynamics-as-models-for-the-interaction-of-fluids-and-flexible-structures-in-biomedical-flows(507cd0db-0116-4258-81f2-8d242e8984fa).html.
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Fluid-structure interaction (FSI), occurrent in many areas of engineering and in the natural world, has been the subject of much research using a wide range of modelling strategies. However, problems with high levels of structural deformation are difficult to resolve and this is particularly the case for biomedical flows. A Lagrangian flow model coupled with a robust model for nonlinear structural mechanics seems a natural candidate since large distortion of the computational geometry is expected. Smoothed particle Hydrodynamics (SPH) has been widely applied for nonlinear interface modelling and this approach is investigated here. Biomedical applications often involve thin flexible structures and a consistent approach for modelling the interaction of fluids with such structures is also required. The Lagrangian weakly compressible SPH method is investigated in its recent delta-SPH form utilising inter-particle density fluxes to improve stability. Particle shifting is also used to maintain particle distributions sufficiently close to uniform to enable stable computation. The use of artificial viscosity is avoided since it introduces unphysical dissipation. First, solid boundary conditions are studied using a channel flow test. Results show that when the particle distribution is allowed to evolve naturally instabilities are observed and deviations are noted from the expected order of accuracy. A parallel development in the SPH group at Manchester has considered SPH in Eulerian form (for different applications). The Eulerian form is applied to the channel flow test resulting in improved accuracy and stability due to the maintenance of a uniform particle distribution. A higher-order accurate boundary model is developed and applied for the Eulerian SPH tests and third-order convergence is achieved. The well documented case of flow past a thin plate is then considered. The immersed boundary method (IBM) is now a natural candidate for the solid boundary. Again, it quickly becomes apparent that the Lagrangian SPH form has limitations in terms of numerical noise arising from anisotropic particle distributions. This corrupts the predicted flow structures for moderate Reynolds numbers (O(102)). Eulerian weakly compressible SPH is applied to the problem with the IBM and is found to give accurate and convergent results without any numerical stability problems (given the time step limitation defined by the Courant condition). Modelling highly flexible structures using the discrete element model is investigated where granular structures are represented as bonded particles. A novel vector-based form (the V-Model) is identified as an attractive approach and developed further for application to solid structures. This is shown to give accurate results for quasi-static and dynamic structural deformation tests. The V-model is applied to the decay of structural vibration in a still fluid modelled using Eulerian SPH with no artificial stabilising techniques. Again, results are in good agreement with predictions of other numerical models. A more demanding case representative of pulsatile flow through a deep leg vein valve is also modelled using the same form of Eulerian SPH. The results are free of numerical noise and complex FSI features are captured such as vortex shedding and non-linear structural deflection. Reasonable agreement is achieved with direct in-vivo observations despite the simplified two-dimensional numerical geometry. A robust, accurate and convergent method has thus been developed, at present for laminar two-dimensional low Reynolds number flows but this may be generalised. In summary a novel robust and convergent FSI model has been established based on Eulerian SPH coupled to the V-Model for large structural deformation. While these developments are in two dimensions the method is readily extendible to three-dimensional, laminar and turbulent flows for a wide range of applications in engineering and the natural world.
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Crowell, Andrew R. "Model Reduction of Computational Aerothermodynamics for Multi-Discipline Analysis in High Speed Flows." The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1366204830.
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