Dissertations / Theses on the topic 'Pipeline pipe'
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1
Hallbom, Donald John. "Pipe flow of homogeneous slurry." Thesis, University of British Columbia, 2008. http://hdl.handle.net/2429/2399.
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The objective of this Thesis is to devise a system for the "rheology-based design" of non-settling (homogeneous) slurry pipelines that is more conducive to application by practicing engineers without impairing its accuracy or utility for research purposes. The cornerstone is the development of a new rheological model and constitutive equation for homogeneous slurry based on the aggregation/deaggregation of the suspended mineral particles. This “yield plastic” model is shown to describe a family of models that includes the Newtonian, Bingham plastic and Casson models as special cases. It also closely approximates the results of many consistency models, including power law, yield power law, Cross and Carreau-Yasuda.
The yield plastic model is then used to develop design equations to determine the pressure-gradient of laminar and turbulent pipe flow. A relative energy dissipation criterion is proposed for the laminar-turbulent transition and shown to be consistent with currently used transition models for Newtonian and Bingham fluids. Finally, a new dimensionless group (the “stress number”) is proposed that is directly proportional to the pressure-gradient and independent of the velocity. When the design equations are presented graphically in terms of the stress number and the plastic Reynolds number, the resulting “design curve diagram” is shown to be a dimensionless (pressure-gradient vs. velocity) pipe flow curve.
The net result is that the hydraulic design of homogeneous slurry systems only requires the use of a single constitutive equation and three engineering design equations. The results are presented in a conceptually easy form that will foster an intuitive understanding of non-Newtonian pipe flow. This will assist engineers to understand the impact of slurry rheology when designing, operating and troubleshooting slurry pipelines and, in the future, other slurry related processes.
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Fischer, W. P. "The mechanics of polymer pipe deformation in pipeline renewal." Thesis, University of Bradford, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.509927.
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Westerhorstmann, Joseph Henry. "The effect of pipe spacing on marine pipeline scour." Thesis, College Station : Texas A&M University, 1988. http://hdl.handle.net/10945/23023.
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CIVINSScour is a major threat to deep water pipelines. A study was performed to determine the relationship between pipe geometry and scour depth, and examine scour hole dimensions under multiple pipes. Model tests were conducted in a two-dimensional wave-current flume facility in which pipes were exposed to unidirectional flow and unidirectional flow with oscillatory motion. The model testing investigated pipes in contact with a sand bed and the effect of pipe spacing on scour. Scour hole profiles were measured and plotted to show the scour hole shape under multiple pipe systems. For two pipe systems, spacing between pipes of 1/2 pipe diameter resulted in less scour depth than full diameter spacing. Unidirectional flow with oscillatory motion resulted in less scour than unidirectional flow. Keywords: Marine engineering; Ocean currents; Stress mechanics; Underwater structures. (KT)
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Salahifar, Raydin. "Analysis of Pipeline Systems Under Harmonic Forces." Thesis, Université d'Ottawa / University of Ottawa, 2011. http://hdl.handle.net/10393/19820.
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Starting with tensor calculus and the variational form of the Hamiltonian functional, a generalized theory is formulated for doubly curved thin shells. The formulation avoids geometric approximations commonly adopted in other formulations. The theory is then specialized for cylindrical and toroidal shells as special cases, both of interest in the modeling of straight and elbow segments of pipeline systems. Since the treatment avoids geometric approximations, the cylindrical shell theory is believed to be more accurate than others reported in the literature. By adopting a set of consistent geometric approximations, the present theory is shown to revert to the well known Flugge shell theory. Another set of consistent geometric approximations is shown to lead to the Donnell-Mushtari-Vlasov (DMV) theory. A general closed form solution of the theory is developed for cylinders under general harmonic loads. The solution is then used to formulate a family of exact shape functions which are subsequently used to formulate a super-convergent finite element. The formulation efficiently and accurately captures ovalization, warping, radial expansion, and other shell behavioural modes under general static or harmonic forces either in-phase or out-of-phase. Comparisons with shell solutions available in Abaqus demonstrate the validity of the formulation and the accuracy of its predictions. The generalized thin shell theory is then specialized for toroidal shells. Consistent sets of approximations lead to three simplified theories for toroidal shells. The first set of approximations has lead to a theory comparable to that of Sanders while the second set of approximation has lead to a theory nearly identical to the DMV theory for toroidal shells. A closed form solution is then obtained for the governing equation. Exact shape functions are then developed and subsequently used to formulate a finite element. Comparisons with Abaqus solutions show the validity of the formulation for short elbow segments under a variety of loading conditions. Because of their efficiency, the finite elements developed are particularly suited for the analysis of long pipeline systems.
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Ritchie, Porter. "The Susceptibility of Electric Resistance Welded Line Pipe to Selective Seam Weld Corrosion." The Ohio State University, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=osu1586336007742949.
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Oliver, Kerry Derrick. "The response of a soil backed submarine pipeline impacted by a dropped object." Thesis, University of Aberdeen, 1999. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU603188.
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The impact of a pipeline by a dropped object has been considered to consist of four distinct impact components: the dropped object, pipeline protection, the soil bed and the pipeline itself. The effect of these components as energy absorbers and the effect on system response has been investigated. Quasi-static and dynamic testing has been earned out to investigate the interaction between the various impact components. Quasi-static testing has been widely used to develop initial predictions, since closer observation of interaction is easier. The validity of applying these predictions to dynamic situations has been addressed using results from dynamic impact testing. The Dropped Object: Two areas have been investigated which address the dropped object within the impact system: the dropped object's impact profile and its deformability. Testing has been carried out to study the effect of typical loading profiles. Research has shown that the dropped object profile significantly effects the pipe response; a cone shaped indentor generates deformation with far less energy than either a wedge or a patch shape. The applicability of a method to predict the interaction between two deforming structures, using a method of shared energy, has been investigated for quasi-static and dynamic loading. During quasi-static testing it was found possible to predict a combined response using individual responses. During dynamic testing prediction was not possible, since inertia effects where found to dominate the response. The Concrete Protective Coating: A programme of work carried out has qualified the role of a pipeline protective coating and assessed the effect of four different types of concrete reinforcement. Summary Although the study has not been exhaustive, it is clear that reinforcements, which hold the concrete coating to the pipe, allow the coating to continue its protection. Fibres added to a concrete mix were found to reduce the damage to the pipe. However mesh reinforcements were found to hold the concrete together most effectively and provided the greatest added protection. The Soil Support: All foundations absorb some energy. Tests have been carried out to investigate the effect of a soil bed on the response of a laterally loaded pipeline. During dynamic tests on sand supported pipes it was noted that no energy was absorbed during the initial deformation, possibly corresponding to local indentation of the pipe wall. After this the sand was seen to react and absorbed a proportion of the energy, depending on the hammer's drop height. The energy absorbed by the soil continued to increase until an energy plateau was reached, after which the soil absorbed no further energy. It was noted that the displacement at which this energy plateau was reached increased as the drop height increased. Two possible causes of the energy plateau have been discussed. The first cause questioned an assumption that the pipe would deform as if on simple supports. The second possible cause suggested a change from dynamic to quasi-static response and investigated the relationship between acceleration, velocity and reaction force. Of the possible causes of the energy plateau, the most likely is thought to be soil related. Investigation into the Deformation of Locally Loaded Pipes: The investigation into pipeline deformation has been carried out using experimental, numerical and theoretical analysis methods. Quasi-static test results have been used to investigate four pipeline parameters and their influence on energy absorbed by the pipeline, (length, L, wall thickness, t, diameter, D and material yield stress, ay). This investigation led to an empirical equation, which brought all energy-displacement (E-8) curves on to a common curve, for a wide range of these variables. This empirical relationship has been developed to predict deformation, for the range of parameters investigated. Dynamic results obtained were normalised using these empirical equations and data was seen to fall into two broad groups, one group comprising seam welded pipe and one group comprising cold drawn pipe. Strain rate effects were proposed as the most likely cause of this bi-grouping. Limitations in the experimentally derived empirical relationship have been identified, resulting from an insufficient range of pipe samples tested.
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Razmara, Mohammad. "Development of an optimum pipeline renovation using Cured-In-Place Pipe (CIPP) techniques." Thesis, University of East London, 2008. http://roar.uel.ac.uk/3887/.
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A study has been performed to investigate resin cure and associated characteristics of composite used in CIPP technique (cured-in-place pipe). CIPP have been employed to rehabilitate deteriorated pipe line. Such liners are often subjected to external hydrostatic pressure which may eventually lead to creep or buckling of the liner within the host pipe. The main objectives of the research are: O To increase flexural modulus without adversely effecting the strength. O To improve the curing and thermo mechanical properties of resin-felt system. Numerous tests were performed on curing systems using DMA (Dynamic Mechanical Analyzer) technique to evaluate material cure and progression for various cataKst percentages. Gellation, vitrification, working open time and glass transition (Tg) were all assessed. A Time Temperature Transformation (TTT) profiles were proposed for three different systems of 2. 3 and 4% w/w catalyst (Figures 8.3. 8.4 and 8.6). indicating the various phases of cure progression (liquid / rubber / glassy and degradation) and further developed using DMA technique in penetration mode. The unique TTT profiles of unsaturated polyester resin in adjacent with nonwoven polyester felt developed to create the similar environment of CIPP production outside of the laboratory condition. In an attempt to enhance the physical and mechanical properties of the liner materials, many different additives were considered. However, it was found that silicon carbide (SiC) nanoparticles can potentially increase the flexural modulus and hardness of the liner materials. However due to the high cost of SiC. various amounts of crystalline SiC>2 (silica) and amorphous SiOo (rice husk ash, RHA) were used to achieve the most optimum mechanical properties. To improve the interfacial interaction between matrix and reinforcement, a suitable coupling agent was used. In the process, Differential Scanning Calorimetric (DSC) was used to evaluate the exothermic behaviour of the samples, scanning electron microscopy (SEM) was used to appraise the mechanism of failure. Thermogravimetry anahsis (TGA) was applied to measure the amount of volatility in the materials. The mechanical performance of all the samples was evaluated using flexural. microhardness, tensile, ring stiffness and creep-recovery tests. Additionally creeprecovery test yielded useful results on the shrinkage of different composite samples containing silica, SiC and RHA. It emerged that by using 8-10% w/w Silica treated by coupling agent resulted in the most cost effective solution, yielding a 30% improvement in flexural modulus of the liner material, this was found to be due to a stronger matrix-reinforcement interfacial interaction. Furthermore, thermo-mechanical properties of different polymer pipe materials used in pipe renovation, including MDPE. HOPE, U-PVC. M-PVC and PUR, were evaluated using DMA. The results of this study indicated that a developed CIPP liner made from polyester felt impregnated with unsaturated polyester resin, containing 10% SiC>2 additive (coupling agent treated) yielded the optimum mechanical performance, with a storage modulus of 1876 MPa, which is noticeably higher than that of different modern pipe materials on the market (PUR. MDPE, HOPE. PVC-U, PVC-M). This improvement in the results has been attributed to the development of optimum interfacial bond strength between silica, matrix and felt. Also this optimum formulation showed excellent toughness performance. The investigation into the thermo-mechanical properties of the optimised CIPP (UPE/F10%SP+CA samples), shows that the developed CIPP has been achieved the best performance in pipeline application.
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Vahedi, Sayeh. "Modelling the effects of inclination and pipe enlargement on outflow following pipeline rupture." Thesis, University College London (University of London), 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.405659.
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Silvestroni, Andrea. "Progettazione, costruzione e posa in opera di un rack per pipeline petrolifere." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2017.
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Il seguente lavoro è relativo alla progettazione e costruzione di un rack per pipeline petrolifere: lo studio qui presentato concerne l’ingegnerizzazione delle attività di cantiere con la verifica della resistenza strutturale delle costruzioni. Si è inoltre cercato di contenere quanto più possibile costi e tempi grazie alla standardizzazione e al riutilizzo delle attrezzature cantieristiche.
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Steiner, Kristi Kalei. "Renewal Engineering Technologies for Drinking Water and Wastewater Pipeline Systems - A State of the Art Literature and Practice Review." Thesis, Virginia Tech, 2012. http://hdl.handle.net/10919/76763.
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Over the last few years, several advancements have been made in water and wastewater pipe renewal technologies that have allowed utilities to utilize innovative renewal techniques that decrease project costs, the impact of the project on the surrounding citizens and environment, and allow for expedited pipeline renewals compared to traditional open trench methods. The challenge now is in getting utilities to implement new innovative technologies within their system. This thesis provides background information on a number of the technologies available for the renewal of water and wastewater system pipelines. It then provides State of the Art Literature and State of the Art Practice Reviews based on technology use trends in literature and technology use trends in utility practice. The information from both reviews is then synthesized to provide a clear view of the state of the water and wastewater pipeline renewal technology industry, including the trends by pipe material, drivers for renewal, and technology type.Master of Science
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Stuart, Alastair David. "The effects of a highly viscous liquid phase on two-phase flow in a vertical pipe and pipeline components." Thesis, Heriot-Watt University, 2005. http://hdl.handle.net/10399/233.
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Marmelo, Patricia C. "Real time evaluation of weld quality in narrow groove pipe welding." Thesis, Cranfield University, 2012. http://dspace.lib.cranfield.ac.uk/handle/1826/7918.
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With the growth in pipeline installations all over the world, there is a great demand for highly productive and robust welding systems. Mechanised pipe welding has been developed over the last 50 years and the present focus is towards development of automated pipeline welding systems. Pipeline welding automation is aimed at reducing costs and improving the installation quality. To attain fully automated pipe welding systems there is a need to rely on sensors and controls systems to mimic human like capabilities, such as visual inspection, in real time. The key aim of this work is to develop and evaluate methods of automatic assessment of weld bead shape and quality during narrow gap GMAW of transmission pipelines. This implies that the measured bead profile will be assessed to determine whether the bead shape will cause defects when the subsequent pass is deposited. Different approaches have been used to conquer the challenge that is emulating human reasoning, all with different objectives in mind. In spite of extensive literature research performed, very little information was found concerning the real time determination and assessment of bead shape quality and none of it was reported to be applied successfully to the pipeline industry. Despite the continuous development of laboratory laser vision systems commercial ones have been on the market for decades, some specifically developed for the welding application. Laser vision sensor systems provide surface profile information, and are the only sensors which can satisfactorily measure bead profile on a narrow groove. In order to be able to use them to automatically assess weld bead shape and quality, a deep understanding of their characteristics and limitations needs to be achieved. Once that knowledge was attained it was then applied to determine the best sensor configuration for this purpose. After that the development of human like judgment algorithms were developed to accomplish the aim that was set. Empirical rules were obtained from an experienced welder regarding the acceptability of bead shapes and were then applied in the developed system with good results. To scientifically evaluate and determine the rules to use in this system, further experiments would be required. The output of the system developed showed very accurate, reliable and consistent results that were true to the external measurements and comparisons performed. The developed system has numerous applications in the pipeline industry and it could easily be implemented on commercial systems.
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Shinohara, Yasuhiro. "Effet d'une pré-déformation sur l'endommagement anisotrope d'un acier pour pipeline de grade API X100." Phd thesis, Ecole Nationale Supérieure des Mines de Paris, 2014. http://pastel.archives-ouvertes.fr/pastel-01073824.
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Dans le cadre de cette étude, l'influence de la pré-déformation sur l'anisotropie du comportement plastique et sur la ténacité d'un acier API X100 pour pipeline a été abordée. Une étude expérimentale approfondie de la microstructure, des propriétés mécaniques et de l'endommagement du matériaux a été mise en oeuvre. Un modèle phénoménologique anisotrope combinant les écrouissagesisotrope et cinématique a été développé dans l'objectif de rendre compte du comportement ductile de cet acier à haute résistance. De plus, un modèle d'endommagement anisotrope a été établi pour représenter l'effet de pré-déformation sur la ductilité et la ténacité de cet acier. L'application des modèles à la flexion sous contrainte illustre, par exemple, l'effet négatif de la pré-déformation sur la charge limite (Moment de flexion maximum) supportée avant flambement du pipe.
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FARZAD, TALEBI. "STUDY ON BEHAVIOR OF BURIED PIPELINES SUBJECTED TO EARTHQUAKE FAULT MOVEMENT BY ANALYTICAL NUMERICAL AND EXPERIMENTAL APPROACHES." Kyoto University, 2020. http://hdl.handle.net/2433/259023.
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Tossey, Brett M. "Steam Oxidation Resistance of Shot Peened Austenitic Stainless Steel Superheater Tubes." The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1306261300.
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Hoza, Martin. "Podchod vodovodu pod dálničním tělesem s využitím mikrotunelu." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2017. http://www.nusl.cz/ntk/nusl-265677.
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During the construction of water pipeline Strelice is necessary to overcome the D1 motorway. This thesis deals with design of the motorway crossing using trenchless technologies. Combination of pipejacking and shield tunneling is chosen. Static calculation includes determination of the jacking force, proposal of the thrust block and assessment of the reinforced concrete jacking pipes.
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Ковтуненко, Олександр Миколайович. "Підбір оптимального матеріалу для елементу паливної системи літака, виходячи з розрахунку на міцність." Master's thesis, КПІ ім. Ігоря Сікорського, 2020. https://ela.kpi.ua/handle/123456789/39574.
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Пояснювальна записка до ДР: 100 с., 46 рис., 11 табл., 33 джерел.
Як об'єкт дослідження було використано модельне представлення елементу тонкостінної конструкції.
Мета даної роботи – підбір матеріалу для виготовлення елементу паливної системи літака. Побудована СЕ модель ділянки конструкції, проведено розрахунок розподілу напружень і деформацій.
Методики дослідження - розбиття на СЕ сітку методом multizone, гідродинамічний і статичний аналізи.
Розробка програмного коду в системі інженерного моделювання ANSYS, який реалізує гідродинамічний та статистичний аналізи тиску i напружень для тонкостінної конструкції із заданою геометрією.
Отримані результати можуть бути використані при проектуванні реальних конструкцій.Report on the DTh: 100 p., 46 fig., 11 tabl., 33 source. A model representation was used as the object of study element of thin-walled construction. The purpose of this work - the selection of material for the manufacture of fuel cell aircraft systems. The SE model of a site of a design is constructed, it is carried out calculation of stress and strain distribution. Research methods - splitting into CE grid by multizone method, hydrodynamic and static analyzes. Development of program code in the ANSYS engineering modeling system, which implements hydrodynamic and statistical analyzes of pressure and stress for thin-walled structure with a given geometry. The obtained results can be used in the design of real structures.
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Бондар, Валерія Андріївна. "Аеродинаміка і теплообмін труб краплеподібної форми." Master's thesis, Київ, 2018. https://ela.kpi.ua/handle/123456789/23241.
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Об’єкт дослідження – процеси аеродинаміки та теплообміну труб
краплеподібної форми при поперечному обтіканні потоком повітря.
Предмет дослідження – вплив режимних параметрів на аеродинамічний
опір і теплообмін труб краплеподібної форми.
Мета роботи – отримання узагальнюючих співвідношень для
розрахунку теплообміну та аеродинамічного опору труб краплеподібної
форми.
Метод дослідження – експериментальне дослідження та CFD-
моделювання.
В даній роботі були проведені експериментальні дослідження та CFD-
моделювання процесів аеродинаміки та інтенсивності конвективного
теплообміну при поперечному обтіканні краплеподібної форми труб, вплив
розташування труб відносно напрямку їх обтікання на інтенсивність
теплообміну та порівняння отриманих результатів з трубами інших форм
поперечного перетину. Була проведена оцінка теплоаеродинамічної
ефективності труб краплеподібної форми. Досліди проведені в діапазоні змін
чисел Рейнольдса ReD = (4..25)·103.
Отримані результати можуть бути використані спеціалістами з
розрахунку теплообмінного обладнання на основі труб краплеподібного
профілю.The object of research - processes of aerodynamics and heat transfer of pipes of a droplet shape with a transverse flow of air. The subject of research - the influence of regime parameters on aerodynamic resistance and heat exchange of tubular droplet forms. The purpose of work – obtaining generalizing relations for calculation of heat transfer and aerodynamic resistance of droplet-shaped tubes. The method of research – experimental research and CFD-modeling. In this paper, experimental studies and CFD-simulation of aerodynamics and convective heat transfer intensity at transverse flow around the drop-shaped tubes, the effect of the arrangement of the pipes in relation to the direction of their flow on the heat transfer intensity and comparison of the results with the pipes of other forms of the cross-section were carried out. An estimation of heat aerodynamic efficiency of droplet-shaped pipes was performed. Experiments are carried out in the range of changes in Reynolds numbers ReD = (4..25)·103. The obtained results can be used by specialists in the calculation of heat- exchange equipment on the basis of pipes of a brittle profile.
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Jahodová, Miroslava. "Pevnostní návrh potrubí." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2015. http://www.nusl.cz/ntk/nusl-231082.
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The subject of this thesis is strength design of pipe connecting furnace of continuous catalytic reforming with reactor. First is realize analytical design of individual parts according to ASME VIII, ČSN EN 12952-3 a ČSN EN 13480-3. It is also design and optimize supporting pipe using Caesar II. At the end of work is creating isometric documentation.
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Запухляк, В. Б. "Удосконалення техніки і технології проведення робіт з реконструкції і ремонту трубопроводів." Thesis, Івано-Франківський національний технічний університет нафти і газу, 2011. http://elar.nung.edu.ua/handle/123456789/1956.
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Дисертацію присвячено удосконаленню технічних засобів і технологій проведення безвогневого врізання в діючий газонафтопровід під тиском на етапах реконструкції та ремонту. Досліджено і проаналізовано процес формування температурного поля від колового руху зварювальної дуги як джерела тепла в стінці діючого трубопроводу. Проведені експериментальні дослідження залежності механічних характеристик трубних сталей від температури. На основі проведених теоретичних і експериментальних досліджень розроблені рекомендації з удосконалення безвогневого методу врізання в діючий трубопровід під тиском. Результати промислових випробувань підтверджують високу ефективність проведених досліджень і розробок. Створено і затверджено галузеву методику «Типові розрахунки показників надійності систем газонафтопостачання»The thesis is devoted to the improvement of technical means and technologies of hot tapping into a running oil and gas pipeline under the pressure at the stages of reconstruction and maintenance. It is developed and analyzed the process of forming of temperature field from a circular motion of welding arc as a heat source in the wall of running pipeline. It is conducted the experimental research of mechanical characteristic dependence of pipe steel on temperature. On the basis of the conducted theoretical and experimental researches, the recommendation on the improvement of hot tapping into a running pipeline under the pressure is made. Industrial testing results confirm high effectiveness of the conducted research and developments. It is developed and approved an industrial strategy, named “Typical Calculations of the Reliability Index of Oil and Gas Supply Systems”.
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Yonan, Shafik J. "Pipe jacking forces in sand." Thesis, Loughborough University, 1993. https://dspace.lboro.ac.uk/2134/15343.
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In this research work, a comprehensive review of investigations into pipe jacking operations, and in particular the forces generated during the process, is presented. The factors affecting these forces were examined and their influence was studied in order to give a clear indication on the their magnitude and behaviour. A model scale testing facility, based on a 1.8m X 1.5m X 1.5m high steel tank, has been developed together with hydraulic jacking facilities and scale model pipes of 200mm diameter having both steel and concrete surfaces. In this facility the actual pipe jacking operation can be simulated, so that a study of the jacking forces could be made with the use of appropriate instrumentation techniques and computerised data recording. A series of tests was conducted to examine the influence of several parameters on the jacking forces, such as overcut ratio, type of soil, type of pipe surface, overburden pressure, and the rate of jacking. These parameters were in relation to the distance jacked. Two granular soils, uniformly graded Leighton Buzzard sand and well-graded River sand, were used as the material surrounding the pipeline, that is the material through which the pipes were jacked. Laboratory analysis on the soil materials was conducted and the relationship between results obtained from these tests and scale model testing were established. The interface friction between the surface of the pipeline and the surrounding soil was determined. The results show a peak in the jacking forces at the start of the jacking process, followed by a decrease and leveling off as the jacking continued. The graph is very similar to the stress/strain relationship of a typical granular soil. Both steel and concrete pipes were used in the tests to detennined the influence of pipe surface, and to a lesser degree pipe joint, characteristics. Higher forces were recorded for concrete pipes. The jacking rate was kept constant and consistent for all tests. It was found to have little effect on the magnitude of the jacking forces. The jacking forces were measured automatically using a computer. The results show a clear trend of increase in the jacking forces when the overburden pressure and jacking length were increased. Tests using different overcut ratios have indicated that a minimum jacking force might be achieved at a specific overcut ratio. The results of this research show that the jacking forces are influenced by a number of parameters. These include the overburden pressure, overcut ratio, pipe diameter, jacking length and the influence of the surrounding material. This is fully demonstrated by establishing a method of jacking forces prediction, termed herein the Loughborough Method.
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Pavlíček, David. "CFD modelování mísení kapalin v potrubí." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2018. http://www.nusl.cz/ntk/nusl-387733.
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This work is focused on computational modelling of mixing fluids in pipeline with static mixers. Main objective is to analyze several selected static mixers in a particular industrial application, namely dosing of the aluminium sulphate solution in the clarification process for potable water treatment. The analysis focuses on the degree of mixedness and pressure loss of individual mixers. Further, the aim of this work is to process the search of available types of static mixers. The benefit of this work is at least an effort to motivate the reader to deeper understanding of the mixing fluids, especially by static mixers.
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Maschner, Emil Alexis. "Vertical buckling of heated submarine pipelines." Thesis, London South Bank University, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.336365.
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Plácido, Joa̧o Carlos Ribeiro. "Development of a predictive drillpipe fatigue model and experimental verification /." Access abstract and link to full text, 1994. http://0-wwwlib.umi.com.library.utulsa.edu/dissertations/fullcit/9500707.
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Kirby, Travis W. "Capacitive sensor technology for polyethylene pipe fault detection." Morgantown, W. Va. : [West Virginia University Libraries], 2009. http://hdl.handle.net/10450/10080.
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Thesis (M.S.)--West Virginia University, 2009.Title from document title page. Document formatted into pages; contains vii, 43 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 14).
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Xie, Qingqing. "Study of mass transfer and turbulence in large pipe flow using limiting current density technique." Ohio : Ohio University, 1997. http://www.ohiolink.edu/etd/view.cgi?ohiou1184606447.
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Tanbakuei, Kashani Majid. "Effect of Forming Process on the Deformational Behaviour of Steel Pipes." Thesis, Université d'Ottawa / University of Ottawa, 2017. http://hdl.handle.net/10393/35914.
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Buried pipeline networks play a vital role in the transportation of oil and natural gas from centers of production to centers of consumption. A common manufacturing technique for such pipes is the UOE process, where a flat steel plate is first formed into a U shape, then into an O shape, welded at the seam, and mechanically expanded before being shipped on site. The UOE forming process deforms the pipe material plastically and induces residual strains in the pipe.
Such pipes are commonly buried on side and then are pressurized under the high head of the fluids they convey which induce hoop stresses as high as 80% of the pipe yield strength. When buried pipelines cross the regions of discontinuous permafrost, they undergo differential frost heaving, inducing significant bending deformations, which potentially induce local buckling in the pipe wall. To control local buckling, design standards impose threshold limits on buckling strains. Such threshold values are primarily based on costly full-scale experimental results. Past nonlinear finite
element analysis attempts aiming at determining the threshold buckling strains have neglected the presence of residual stresses induced by the UOE forming and were thus found to grossly overestimate the buckling strains compared to those based experiments.
Within the above context, the present study focuses on developing a numerical technique to predict the residual stresses induced during UOE forming, and incorporating the induced residual stresses in 3D nonlinear FEA modeling to more reliably predict buckling strain limits. Comparisons with conventional analysis techniques that omit residual stresses reveal the importance of incorporating
residual stresses induced in forming when quantifying buckling strains.
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Stříž, Michal. "Konstrukční návrh pece." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2012. http://www.nusl.cz/ntk/nusl-230111.
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This master´s thesis deals with issues of tube furnaces in the process industries, especially with a design of a transfer pipeline, which is one of the main parts of the furnace. According to the requirements, designed pipeline is stress analyzed using the two pipeline programs Japar and Caesar II, that are briefly described. In addition to this design several variants of analysis are performed and the results are compared. Comparison helps to explain the diversity of the programs. For example, the effect of elbows on the stress analysis. The master´s thesis also describes the factors that affect the working life of the furnace.
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Van, Deventer Christoffel Gerhardus. "Guidelines for predicting the remaining life of underground pipe networks that are subjected to the combined effects of external corrosion and internal pressure." Diss., Pretoria : [s.n.], 2002. http://upetd.up.ac.za/thesis/available/etd-10312005-113656/.
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Morrow, Damian. "Pipe-soil interaction on a clay seabed." Thesis, University of Dundee, 2016. https://discovery.dundee.ac.uk/en/studentTheses/a39e6fbb-c6f0-44cc-9419-4b018db357af.
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Subsea pipelines form an integral part of the infrastructure associated with offshore oil and gas developments. These pipelines fulfill a range of functions from linking extraction wells to other subsea infrastructure to transporting products onshore, or to a central processing facility. Ancillary pipelines may also be present for gas or water injection to the reservoir or transporting additives. Pipelines are typically installed directly onto the seabed and, in the absence of significant drivers to undertake burial operations, they may remain on the seabed for the remainder of their design life. This is typically the case for deepwater developments. Subsea pipelines are subjected to a wide range of load cases including, self weight, installation loads, thermal and pressure driven expansion and hydrodynamic loading. Design of pipeline systems to accommodate these load cases requires an understanding of pipe-soil interaction. This thesis reports the results of a research study investigating pipe-soil interaction on a clay seabed, as relevant to the design of subsea pipeline systems. This study has utilised numerical analysis techniques based on the finite difference code FLAC to investigate a range of problem definitions. These problem definitions include pipelines subject to both vertical loading (V) and combined vertical and horizontal (V-H) loading. Factors such as variation in interface conditions, large strain and large displacement effects, soil unit weight effects and variation in shear strength conditions were considered in these problem definitions. Reliability based analysis techniques have also been used to investigate both V and V-H loading problem definitions. The analyses and investigations undertaken as part of this study generally achieved the following; reproduction and validation of earlier research with additional interpretation, extension of problem definitions to deeper pipeline embedment depths and investigation of pipe-soil interaction problem definitions that have not previously been considered. Reliability based analysis techniques have also provided some interesting insights into the impact of soil shear strength variation as well as providing a fundamental link between safety factors and probability of failure. Application to design practice of this, and similar studies, has been considered as part of this thesis and potential areas for future research have also been suggested.
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Vishwakarma, Anmol. "Development Of A Performance Analysis Framework For Water Pipeline Infrastructure Using Systems Understanding." Thesis, Virginia Tech, 2019. http://hdl.handle.net/10919/87081.
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The fundamental purpose of drinking water distribution systems is to provide safe drinking water at sufficient volumes and optimal pressure with the lowest lifecycle costs from the source (treatment plants, raw water source) to the customers (residences, industries). Most of the distribution systems in the US were laid out during the development phase after World War II. As the drinking water infrastructure is aging, water utilities are battling the increasing break rates in their water distribution system and struggling to bear the associated economic costs. However, with the growth in sensory technologies and data science, water utilities are seeing economic value in collecting data and analyzing it to monitor and predict the performance of their distribution systems. Many mathematical models have been developed to guide repair and rehabilitation decisions in the past but remain largely unused because of low reliability. This is because any effort to build a decision support framework based on a model should rest its foundations on a robust knowledge base of the critical factors influencing the system, which varies from utility to utility. Mathematical models built on a strong understanding of the theory, current practices and the trends in data can prove to be more reliable. This study presents a framework to support repair and rehabilitation decisions for water utilities using water pipeline field performance data.Master of Science
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Javaid, Muhammad Salik. "Measurement of pressure distribution around a circular cylinder on a plane wall in oscillatory flow." Diss., Georgia Institute of Technology, 1994. http://hdl.handle.net/1853/20733.
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Gao, Xiang. "Hydrodynamics of HCP with slopes and bends /." free to MU campus, to others for purchase, 1999. http://wwwlib.umi.com/cr/mo/fullcit?p9962524.
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Yan, Pei. "High frequency induction welding & post-welding heat treatment of steel pipes." Thesis, University of Cambridge, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.609702.
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Yayla, Pasa. "Rapid crack propagation in polyethylene gas pipes." Thesis, Imperial College London, 1991. http://hdl.handle.net/10044/1/8711.
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Tran, Vinh Cong. "Imperfect upheaval subsea pipeline buckling." Thesis, Sheffield Hallam University, 1994. http://shura.shu.ac.uk/3179/.
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The objective of the research programme has been to develop a set of theoretical models suited to the perceived needs of industrial practice with regard to in-service, subsea pipeline buckling. The role of imperfections is shown to be of central importance. These factors are considered in the context of modern offshore engineering practice, including the particular employment of trenching and/or burial for purposes of protection. Novel, small scale, full thermo-mechanical system testing is presented, the design and construction of the actual experimental set-up being a key feature of the research programme. Subsidiary geotechnical experimentation is also undertaken. Theoretical studies employing the empirical data provided by latter are assessed against the resulting full system experimental data. With an introduction to the purpose of the research programme and the physical problem and its mechanical demands given in Chapter 1, Chapter 2 serves to clarify the factors involved. Although novelty involving the testing of burial pipe elements is present in the experimental studies of Chapter 3 the majority of original work lies in the theoretical studies of Chapters 4 to 6 and the full system experimentation reported in Chapter 7. The results of forty-five tests are therein provided and theoretical/experimental correlation considered. Definition of the upheaval state, crucial to offshore engineering requirements, is considered to be effectively provided for with regard to symmetric prototype configurations and a software suite of complementary models has been developed.
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Van, Sittert Fritz Peter. "The effect of pipe roughness on non-Newtonian turbulent flow." Thesis, Cape Technikon, 1999. http://hdl.handle.net/20.500.11838/1035.
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Thesis (MTech (Civil Engineering))--Cape Technikon, Cape Town, 1999Pipe roughness is known to greatly increase the turbulent flow friction factor for Newtonian fluids. The well-known Moody diagram shows that an order of magnitude increase in the friction is possible due to the effect of pipe roughness. However, since the classical work of Nikuradse (1926 -1933), very little has been done in this area. In particular, the effects that pipe roughness might have on non-Newtonian turbulent flow head loss, has been all but totally ignored. This thesis is directed at helping to alleviate this problem. An experimental investigation has been implemented in order to quantify the effect that pipe roughness has on non-Newtonian turbulent flow head loss predictions. The Balanced Beam Tube Viscometer (BBTV), developed at the University of Cape Town, has been rebuilt and refined at the Cape Technikon and is being used for research in this field. The BBTV has been fitted with pipes of varying roughness. The roughness of smooth P\'C pipes was artificially altered using methods similar to those of Nikuradse. This has enabled the accumulation of flow data in laminar and turbulent flow in pipes that are both hydraulically smooth and rough Newtonian and non-Newtonian fluids have been used for the tests. The data have been subjected to analysis using various theories and scaling laws. The strengths and problems associated with each approach are discussed and It is concluded that roughness does have a significant effect on Newtonian as well as non-Newtonlan flow.
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Петрина, Д. Ю. "Вплив експлуатаційної деградації матеріалів і зварних з'єднань магістральних нафтогазопроводів на їх працездатність." Thesis, Івано-Франківський національний технічний університет нафти і газу, 2011. http://elar.nung.edu.ua/handle/123456789/1902.
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У дисертації на основі вивчення змін фізико-механічних і електрохімічних властивостей, механізмів руйнування тривало експлуатованих сталей нафтогазопроводів та їх зварних з’єднань вдосконалено існуючі та розроблено нові методи оцінки характеристик деградованого металу з позиції його подальшої працездатності.
Виявлено аномалію у механічній поведінці тривало експлуатованих сталей, що проявляється в зменшенні твердості та міцності за одночасного зниження опору крихкому руйнуванню та відносного звуження і в різному характері зміни показників пластичності (зменшенні у і рості б).
Найефективніше експлуатаційна деградація трубних сталей проявляється за більш жорстких умов навантаження, понижених температурах, наявності агресивних середовищ. Вона помітно погіршує електрохімічні характеристики, особливо поляризаційний опір.
Розроблений новий метод статистичної оцінки залежності ударної в’язкості трубної сталі 17Г1С та її складових від температури випробувань. Висока чутливість ударної в’язкості до деградації сталей зумовлена зниженням складової роботи поширення тріщини.
Встановлено, що періоди зародження та докритичного росту корозійно-механічної тріщини є меншими для експлуатованої сталі порівняно з новою.
Тривала експлуатація спричиняє деградацію характеристик пластичності, ударної в’язкості, тріщиностійкості та корозійної тривкості зварних з’єднань .In the thesis on the basic of study of physico-mechanical and electrochemical in properties and destruction mechanisms of the long-term operating steel of oil and gas pipelines the existing methods of assessment of degradation metal from the viewpoint of its durability were improved and developed were the new ones. The abnormality in the mechanical behavior of long-term operating steel has been revealed that results in hardness and toughness decrease at simultaneous reduction of resistance to brittleness destruction and relative contraction and in a different mode of changes of plasticity indices (lowering xp and increasing 8). The most efficient pipeline steel operating degradation is revealed at more sever loading conditions, decreased temperatures and the availability of corrosive medium. It significantly worsens electrochemical characteristics, particularly resistance to polarization. Developed was, the new method of statistical assessment of dependence of impact toughness of pipeline steel 17Г1C and its components upon the testing temperature. High sensitivity of impact toughness to steel degradation is due to such operational component as crack expansion. It has been determined that the periods of corrosive-mechanical crack nucleation and its subcritical growth are shorter for operating steel in comparison with the newly made. The long-term operation leads to degradation of characteristics of plasticity, impact toughness, crack growth resistance and corrosive resistance durability of welded joints.
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Chen, Zhenxin. "The mechanical behaviour and fatigue analysis of flexible pipes." Thesis, Heriot-Watt University, 1990. http://hdl.handle.net/10399/1292.
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Staheli, Kimberlie. "Jacking Force Prediction: An Interface Friction Approach based on Pipe Surface Roughness." Diss., Available online, Georgia Institute of Technology, 2006, 2006. http://etd.gatech.edu/theses/available/etd-07052006-203035/.
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Thesis (Ph. D.)--Civil and Environmental Engineering, Georgia Institute of Technology, 2007.Dr. J. David Frost, Committee Chair ; Dr. G. Wayne Clough, Committee Co-Chair ; Dr. William F. Marcuson III, Committee Member ; Dr. Paul W. Mayne, Committee Member ; Dr. Susan Burns, Committee Member.
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Al-Khazaali, Mohammed. "Soil-Pile, Pile Group Foundations and Pipeline Systems Interaction Behavior Extending Saturated and Unsaturated Soil Mechanics." Thesis, Université d'Ottawa / University of Ottawa, 2019. http://hdl.handle.net/10393/38843.
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Rapid growth in population along with positive trends in global economy over the past several decades has significantly contributed to an increased demand for various infrastructure needs worldwide. For this reason, the focus of this thesis has been directed towards extending the mechanics of unsaturated soils, which is an emerging geotechnical engineering field to investigate the behavior of two key infrastructure systems, namely pile foundations and energy pipeline systems. The mechanism of soil-pile foundations and soil-pipeline systems interaction behavior has several similarities.
Both these infrastructure facilities require comprehensive understanding of the soil-structure interaction mechanism. Reliable estimation of mechanical properties of both the soil and the soil-structure interface is required for the rational interpretation the load-displacement behavior of pile foundations and pipeline systems. Currently, the design of systems is predominantly based on design codes and guidelines that use empirical procedures or employ the principles of saturated soil mechanics. In many scenarios, pile foundations extend either totally or partly in unsaturated soils as the groundwater table level in many regions is at a greater depth. Such scenarios are commonly encountered in semi-arid and arid regions of the world. In addition, pipeline systems are typically buried at shallow depths in unsaturated soil strata, which are susceptible to wetting and drying, freezing and thawing cycles or both, due to seasonal environmental changes. Capillary stress or matric suction in the unsaturated zone increases the effective stress contribution towards the shear strength and stiffness of soil and soil-structure interface. Extending saturated soil mechanics to design or analyze such structures may lead to erroneous estimation of pile foundation carrying capacity or loads transferred on pipeline body from the surrounding unsaturated soil.
Experimental, analytical and numerical investigations were undertaken to study the behavior of single pile, pile group, and pipeline systems in saturated and unsaturated sands under static loading. The experimental program includes 40 single model pile and 2×2 pile group, and six prototype pipeline tests under saturated and unsaturated condition. The results of the experimental studies suggest that matric suction has significant contribution towards the mechanical behavior of both pile foundation and pipeline system.
The axial load carrying capacity of single pile and pile group increased approximately 2 to 2.5 times and the settlement reduced significantly compared to saturated condition. The influence of matric suction towards a single pile is significantly different in comparison to pile group behavior. The cumulative influence of matric suction and stress overlap of pile group behavior in sandy soils result in erroneous estimation of pile group capacity, if principles of saturated soil mechanics are extended. Group action plays major role in changing the moisture regime under the pile group leading to incompatible stress state condition in comparison to single pile behavior.
On the other hand, the peak axial load on the pipe is almost 2.5 folds greater in unsaturated sand that undergoes much less displacement in comparison to saturated condition. Such an increase in the external axial forces may jeopardize the integrity of energy pipeline systems and requires careful reevaluation of existing design models extending the principles of unsaturated soil mechanics. Two analytical design models to estimate the axial force exerted on pipeline body were proposed. The proposed models take account of matric suction effect and soil dilatancy and provide smooth transition from unsaturated to saturated condition. These models were developed since measurement of the unsaturated soil and interface shear strength and stiffness properties need extensive equipment that require services of trained professional, which are expensive and time consuming. The models utilize the saturated soil shear strength parameters and soil-water characteristic curve (SWCC) to predict the mechanical behavior of the structure in saturated and unsaturated cohesionless soils. The prototype pipeline experimental results were used to verify the proposed models. The predicted axial force on pipeline using the proposed models agrees well with the measured behavior under both saturated and unsaturated conditions.
Moreover, numerical techniques were proposed to investigate the behavior of pile foundation and pipeline system in saturated and unsaturated sand. The proposed methodology can be used with different commercially available software programs. Two finite element analysis programs were used in this study; namely, PLAXIS 2D (2012) to simulate soil-pile foundation behavior and SIGMA/W (2012) to simulate soil-pipeline system behavior. The proposed techniques require the information of unsaturated shear strength and stiffness, which can be derived from saturated soil properties and the SWCC. The model was verified using pile and pipeline test results from this study and other research studies from the published literature. There is a good agreement between the measured behavior and the predicted behavior for both the saturated and unsaturated conditions. The methodology was further extended to investigate the behavior of rigid and flexible pipelines buried in Indian Head till (IHT) during nearby soil excavation activity. The simulation results suggest that excavation can be extended safely without excessive deformation to several meters without the need for supporting system under unsaturated condition.
The studies summarized in the thesis provide evidence that the principles of saturated soil mechanics underestimate the pile foundations carrying capacity as well as the axial force exerted on pipelines in unsaturated soils. Such approaches lead to both uneconomical pile foundation and unsafe pipeline systems designs. For this reason, the pile and pile group carrying capacity and pipeline axial force should be estimated taking into account the influence of matric suction as well as the dilatancy of the compacted sand. The experimental studies, testing techniques along with the analyses of test results and the proposed analytical and numerical models are useful for better understanding the pile foundation and buried pipeline behaviors under both saturated and unsaturated conditions. The proposed analytical and finite element models are promising for applying the mechanics of unsaturated soils into conventional geotechnical engineering practice using simple methods.
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Macaro, Giulia. "Distinct element modelling of pipe-soil interaction for offshore pipelines on granular soils." Thesis, University of Oxford, 2015. http://ora.ox.ac.uk/objects/uuid:cf38c129-502f-4d7d-aa8c-fea5d95ad2d2.
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Offshore on-bottom pipelines are subjected to cycles of thermal and pressure-induced axial expansion, which can cause them to buckle laterally. For an elegant and cost-effective solution, lateral buckling is allowed in a controlled manner. Of the various design parameters, the soil resistance has the greatest associated uncertainty. Previous studies of lateral pipe-soil interaction have used laboratory model tests and continuum-based numerical methods. However, they are economically and computationally expensive, and have mostly been restricted to pipes on undrained clay. To overcome this limitation, this thesis introduces the distinct element method (DEM) as a novel numerical tool for the study of lateral pipe-soil interaction for partially embedded offshore pipelines on sandy seabeds. The DEM directly models the particulate nature of sandy soils, allowing large displacements of discrete bodies and providing insights into the mechanics of the soil at a particle level. Pipe{soil interaction is studied by DEM analyses through four separate research stages: (i) mechanical characterisation of the soil, (ii) specimen preparation and pipeline implementation, (iii) small displacement pipe loading tests and (iv) large displacement pipe loading tests. The soil is modelled as an assembly of spherical particles exchanging contact forces, energy and momentum when they interact. At the microscopic scale, a novel moment-relative rotation contact law is introduced to account for the irregular shape of real sand grains. At a macroscopic scale, the mechanical behaviour of the sand is calibrated using experimental triaxial test data. Additional work includes the numerical preparation of a soil assembly and the implementation of a pipeline object in the open-source DEM code Yade. A novel specimen preparation technique is developed to assemble a homogeneous sample at a desired relative density. The pipeline is implemented as a cylindrical body with a continuously curved surface and a specific mass. Small displacement loading tests are performed, with a segment of the pipeline interacting with a 3D prismatic soil domain, replicating plane strain conditions. The influence of particle size, domain thickness, loading velocity and damping are investigated. The findings provide valuable recommendations for performing DEM simulations of this problem, balancing numerical accuracy and computational effort. Large displacement loading tests are performed to validate the DEM approach and to obtain detailed insights into the nature of the pipe-soil interaction. Monotonic vertical and lateral loading simulations are quantitatively compared with laboratory results. To replicate realistic loading conditions of the pipeline on the seabed, cyclic large displacement tests are also performed. Both the monotonic and the cyclic tests show a good level of agreement with experimental results obtained in previous research. Moreover, the numerical analyses provide insights into the evolution of particle motion and the failure mechanism within the soil.
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Meyer, Vinícius. "PIPEL: modelo de gerência da elasticidade para aplicações organizadas em pipeline." Universidade do Vale do Rio dos Sinos, 2016. http://www.repositorio.jesuita.org.br/handle/UNISINOS/5772.
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No ambiente da computação workflows tornam-se um padrão crescente para diversos experimentos científicos. Workflows científicos são compostos por várias aplicações estruturadas em um fluxo de atividades, onde o resultado de uma delas torna-se a entrada de outra. Uma aplicação pipeline é um tipo de workflow que recebe um conjunto de tarefas, as quais devem passar por todas as fases desta aplicação de forma sequencial, o que pode levar a um tempo de execução proibitivo. Tendo em vista este problema, aplicações pipeline podem se beneficiar da utilização de recursos distintos para cada um dos estágios, ou seja, executadas em plataformas distribuídas. Entretanto, dependências e necessidade especificas da computação distribuída surgem devido à interação entre os estágios de processamento e a grande quantidade de dados que devem ser processadas. O fluxo de entrada para aplicações que utilizam padrões pipeline pode ser intenso, inconstante ou irregular. De acordo com o comportamento do fluxo de tarefas, alguns estágios da aplicação podem ter seu desempenho prejudicado, atrasando os estágios subsequentes e por fim interferindo no desempenho da aplicação. Uma alternativa para resolver isto é alocar o máximo de recursos disponíveis (over-provisioning) em cada estágio da aplicação. Entretanto, esta técnica pode gerar um alto custo de infraestrutura, além da possibilidade que em alguns momentos os recursos fiquem ociosos. Sendo assim, a elasticidade em ambiente de nuvem computacional aparece como uma alternativa, explorando o conceito “pagar somente pelo que usar” (pay-as-you-go). Nesse contexto é proposto um modelo de elasticidade baseado na camada PaaS (Plataform as a Service) da nuvem, intitulado de Pipel. Este modelo permite que aplicações pipeline tirem vantagem do provisionamento dinâmico de recursos da infraestrutura de nuvem computacional. Pipel utiliza uma abordagem reativa, fazendo uso de thresholds para a tomada de decisões da elasticidade, baseados na carga de CPU das máquinas virtuais em cada estágio da aplicação. Cada estágio possui um balanceador de carga (chamado de controlador de estágio) e um determinado número de recursos em operação. O controlador do estágio recebe as tarefas que o estágio deve executar, as aloca em uma fila onde são distribuídas nas máquinas virtuais disponíveis em seu estágio. De acordo com regras estabelecidas Pipel realiza ações de elasticidade sobre o ambiente de nuvem. Para validar esta proposta foi desenvolvido um protótipo, o qual foi testado em dois cenários: (i) sem uso de elasticidade e (ii) com uso da elasticidade. Em cada cenário utilizou-se quatro cargas de processamento: (i) Crescente; (ii) Decrescente; (iii) Constante e (iv) Oscilante. Os resultados apresentam uma redução de 38% no tempo da execução da aplicação com o uso da elasticidade provida por Pipel.
In the computing environment workflows has become a standard for many scientific experiments. Scientific workflows consist of several applications structured in an activity flow, where the output of one becomes the input of another. A pipeline application is a type of workflow that receives a set of tasks, which must pass through all stages of this application in a sequential manner, which can lead to a prohibitive execution time. Considering this problem, pipeline applications can benefit from the use of different resources for each stage, or performed in a distributed way. However, specific dependencies and distributed computing problems arise due to the interaction between the processing stages and the mass of data that must be processed. The input stream for applications that use pipeline standards can be intense, erratic or irregular. According to the task flow behavior some stages may have degraded performance, delaying subsequent stages and ultimately interfering in the application’s performance. An alternative to solve this is to allocate the maximum available resources (over-provisioning) in each application stage. However, this technique can generate a high infrastructure costs and the possibility that some resources remain idle in certain moments. Thus, the elasticity in cloud computing environments appears as an alternative, exploring the pay-as-you-go concept. In this context, we propose an elastic model based on the PaaS layer (Platform as a Service) cloud, named Pipel. This model allows pipeline applications to take advantage of the dynamic resource provisioning capabilities of cloud computing infrastructure. Pipel uses a reactive approach, using thresholds for elasticity decisions based on the CPU load of virtual machines in each application stage. Each stage has a load balancer (called stage controller) and a number of operating resources. The stage controller receives the tasks that the stage should run, allocates in a queue and then distribute the tasks in virtual machines available at each stage. According to established rules Pipel performs elasticity actions on the cloud environment. To validate this proposal we developed a prototype that has been tested in two different scenarios: (i) without elasticity and (ii) with elasticity. In each scenario we used four different processing loads: (i) Increasing; (ii) Decreasing; (iii) Constant and (iv) Oscillating. The results showed a reduction of 38% of the application’s execution time using the elasticity provided by Pipel.
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Alves, Iberê Nascentes. "Slug flow phenomena in inclined pipes /." Access abstract and link to full text, 1991. http://0-wwwlib.umi.com.library.utulsa.edu/dissertations/fullcit/9203792.
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Alzuhd, Tahir Hussein Hasan. "Pressure losses associated with slurry flow in horizontal pipelines." Thesis, University of Hertfordshire, 2003. http://hdl.handle.net/2299/14146.
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The flow of solid liquid mixtures (slurries) has attracted much attention in research work because of its importance to industry. Prediction of pressure losses associated with slurry flow helps pipe designers select the correct pipe sizes for optimum energy consumption, equipment sizing and reliable operation of the pipeline networks. Many workers developed empirical correlations, but due to the randomness of the problem they seem of limited use in design applications because they do not contain an assessment except by trial and error, which is costly. The existence of more than one particle size poses more complexities to the slurry flow problem but it is in need in practical applications. The aims of this work are justified under the light of the observations on the state of the art in slurry transport. An experimental program is designed to highlight the effects of this problem through a predetermined set of test runs. The variables are grouped to optimise the number of experiments and to remove the effect of dimensions on the prediction method The test rig is built to serve the aims of this exercise and test runs conducted, results grouped and discussed for polyfractional slurries. A mathematical model is developed in the form of an empirical correlation. Statistical tests are employed to verify the goodness of fit. Finally, conclusions and recommendations for further work are listed.
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Ali, Imad. "CFD prediction of stratified and intermittent gas-liquid two-phase turbulent pipe flow using RANS." Thesis, University of Manchester, 2017. https://www.research.manchester.ac.uk/portal/en/theses/cfd-prediction-of-stratified-and-intermittent-gasliquid-twophase-turbulent-pipe-flow-using-rans(4fa69a04-51b9-4b5e-8bef-76cc93135407).html.
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The transport of multi-phase flow in pipelines can be met in a wide range of industrial applications, including the oil and gas industry, showing great savings in developments. In addition, as the exploration of new fields in oil and gas expands to harsh environments, such as ocean or polar, the multi-phase flow transport sometimes becomes the only feasible option. The important features of such multi-phase flow applications include flow regimes, pressure drop and liquid holdup. The precise estimation of these parameters has significant technical and economical impacts on the design and operation of an oil and gas pipelines. Many prediction correlations and methods have been developed; computational fluid dynamics (CFD) being one of them. This type of modelling approach has many advantages over the conventional approaches such as its ability to solve 3D transient problems; offering access to a wealth of information which with conventional techniques is extremely difficult to obtain. Therefore, interest in applying CFD for multi-phase flow transport in pipelines has been on the rise. This thesis is aimed at presenting CFD simulations based on the use of the Volume of Fluid model (VOF) approach for various conditions of gas-liquid turbulent flow in a horizontal circular pipe. In the current VOF formulation in addition to the secondary phase transport equation, a geometric reconstruction technique based on a piecewise-linear interface construction approach is used for reconstructing the interface. A number of multi-phase studies using different turbulence models to the current one have recently appeared in the open literature for simple flow geometries such as rectangular channels. However, most of them assume specific boundary conditions (such as fully-separated phases for stratified flows, the use of square wave at the inlet to represent slug flow or imposing an interfacial disturbance to initiate slugging). These require case-by-case empirical information such as, interfacial roughness for stratified- or slug frequency for intermittent-flow. However, most of them have not presented any detailed validation of their results. The former two points are very crucial for the design of transport pipelines as a pre-knowledge of the operative flow regime and empirical information are not available at the design stage. The predictive accuracy of the present simulations is tested against most common mechanistic approaches and detailed measurements of stratified two-phase flow in a horizontal pipe of Strand (1993) and have been found to be in reasonable quantitative agreement. For the intermittent flow type cases, the numerical results are qualitatively compared against experiments in a horizontal pipe of Al-alweet (2008). The computed flow data of intermittent flow type are further tested against some empirical and mechanistic correlations; the numerical results are qualitatively in a reasonable agreement. Gas compressibility effects on the simulations of slug flow are also explored and are found to bring about some positive benefit. Overall, the predictive accuracy of the present approach is reasonable and promising, demonstrating the ability of the model to predict different types of flow regimes found in two-phase pipe flows. Furthermore, the proposed model shows potential for general applicability to the design of two-phase pipeline systems as it does not require pre-knowledge of the flow regime or any case-by-case empirical information.
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Kamalarasa, Sanmugarasa. "Buckle propagation in submarine pipelines." Thesis, University of Cambridge, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.328779.
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Glennon, Dermot. "A study of the molecular organisation in structural PVDF." Thesis, University of Portsmouth, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.310418.
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Thorvaldsen, Gary Sven. "The effect of the particle size distribution on non-Newtonian turbulent slurry flow in pipes." Thesis, Cape Technikon, 1996. http://hdl.handle.net/20.500.11838/896.
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Thesis (MTech (Chemical Engineering))--Cape Technikon, Cape Town,1996The handling of solid-liquid suspensions is an important concern within the chemical and processing industries and many theoretical models have been proposed to try and explain and predict turbulent flow behaviour. However, the prediction of turbulent flow from only the viscous properties of non-Newtonian suspensions has over the years been questioned by researchers. This thesis considers theoretical models well established in the literature and the Slatter model, which uses both the rheology of the suspension and the particle size distribution of the solids. These models are used to analyze the experimental data and the effect that particle size and the particle size distribution has on turbulent flow behaviour. The literature concerning the rheological fundamentals relevant to fluid flow in pipes has been examined. The Newtonian turbulent flow model as well as the non-Newtonian models of Dodge & Metzner, Torrance, Kemblowski & Kolodziejski, Wilson & Thomas and Slatter have been reviewed. Test work was conducted at the University of Cape Town's Hydrotransport Research Laboratory using a pumped recirculating pipe test rig. The test apparatus has been fully described and calibration and test procedures to enable collecting of accurate pipeline data have been presented. Three slurries were used in test work namely kaolin clay, mixture I (kaolin clay and rock flour) and mixture 2 (kaolin clay, rock flour and sand) with ad,s particle size ranging from 24/Lm to 170/Lm. The yield pseudoplastic model has been used to model and predict the laminar flow of the suspensions that were tested and the meth9J adopted by Neill (1988) has been used to determine the rheological constants. The pipeline test results have been presented as pseudoshear diagrams together with the theoretical model lines providing a visual appraisal of the performance of each model. The Slatter model predicts the test data best with the other theoretical models that were considered tending to under predict the head loss. The reason the Slatter model performs better than the other theoretical models is because this model can account for the wall roughness and particle roughness effect. Evidence to support this statement has been presented. This thesis highlights the fact that the particle size distribution is a vitally important property of the suspension and that it does influence turbulent flow behaviour. It shows that turbulence modelling using the particle roughness effect (eg Slatter, 1994) is valid and can be adopted for non-Newtonian slurries. It is concluded that the particle size distribution must be used to determine the particle roughness effect and this effect must be incorporated in the turbulent flow analysis of non-Newtonian slurries.
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Maltby, Timothy Crichton. "The upheaval buckling of buried pipelines." Thesis, University of Cambridge, 1993. https://www.repository.cam.ac.uk/handle/1810/251542.
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