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Age and origin of the sedimentary dikes of the Pipe Creek Junior (Silurian) Reef, Grant County, IndianaBurns, Danny E. 03 June 2011 (has links)
Sedimentary dikes at the Pipe Creek Junior Quarry were found to fill fractures formed by compaction and rotation of the reef flank beds and by regional stresses of less certain origin. A sequence of fracturing events has been established as well as a sequence for the emplacement of dike materials. Most of the carbonate dikes are found to be of Cayugan (Silurian) age, although some of the las carbonates are shown to be of Devonian age due to the presence of rounded detrital quartz grains within them. All of the quartz arenite dikes are found to be of Devonian age and are divided into two major groups: older white arenites and younger brown arenites. The two types of arenties have different characteristics and were deposited under different conditions.The arenites of Pipe Creek Junior Quarry were found to be similar to the arenites of the Bluffton Quarry which are also fracture fillings in Silurian reef rock. Other Devonian sand bodies are compared to the fracture filling and, although they are not identical, they show a similarity in materials and a pattern of environment and deposition that point to a northwestern source for all of the rounded quartz studied in this work. Environmental analysis of the quartz grains indicates a litoral mode of transport and sorting for most of the samples with an ecolian mode present in the sands outside the reef area and as a minor component for some of the younger sands within the reef area.A map of the glaciated quarry surface has been prepared for the purposes of this work and to preserve relationships that are constantly being removed by quarrying of the reef flank beds.
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Über Synchronisationsphänomene nichtlinearer akustischer Oszillatoren / About synchronization phenomena of nonlinear acoustic oscillatorsFischer, Jost January 2012 (has links)
In dieser Arbeit werden die Effekte der Synchronisation nichtlinearer, akustischer Oszillatoren am Beispiel zweier Orgelpfeifen untersucht. Aus vorhandenen, experimentellen Messdaten werden die typischen Merkmale der Synchronisation extrahiert und dargestellt. Es folgt eine detaillierte Analyse der Übergangsbereiche in das Synchronisationsplateau, der Phänomene während der Synchronisation, als auch das Austreten aus der Synchronisationsregion beider Orgelpfeifen, bei verschiedenen Kopplungsstärken. Die experimentellen Befunde werfen Fragestellungen nach der Kopplungsfunktion auf. Dazu wird die Tonentstehung in einer Orgelpfeife untersucht. Mit Hilfe von numerischen Simulationen der Tonentstehung wird der Frage nachgegangen, welche fluiddynamischen und aero-akustischen Ursachen die Tonentstehung in der Orgelpfeife hat und inwiefern sich die Mechanismen auf das Modell eines selbsterregten akustischen Oszillators abbilden lässt. Mit der Methode des Coarse Graining wird ein Modellansatz formuliert. / In this study, synchronization properties observed in a system of nonlinear acoustic oscillators in form of two coupled organ pipes are investigated. From given measurements we extract the effects of synchronization one would expect typically. Furthermore we set our focus to the domains of transition into the synchronization region, when the system is complete synchronized and when it tears off, under the condition of different coupling strengths. We analyze and discuss the observed phenomena concerning their nonlinearities. Using numerical, fluid-dynamic and aeroacoustic simulation techniques we investigate how an organ pipe can be understand as a self-sustained, acoustic oscillator. With the results of the numerical simulations we show, how to reduce the complex fluid-dynamical interplay with the acoustic field inside the pipe to a self-sustained acoustic oscillator. For this process we use the coarse graining method.
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Engineering design and analysis of pipe ramming installationsMeskele, Tadesse 08 February 2013 (has links)
The trenchless technology known as pipe ramming for construction of culverts and buried pipes under roadways or other infrastructure has gained significant popularity due to its cost-effectiveness and ability to alleviate surface disruptions associated with open-cut trenching. Although the experience with pipe ramming is increasing, there has been remarkably little technical guidance available for engineers to appropriately specify aspects of a pipeline or culvert installation, including the planning of feasible layouts, rates of penetration, pipe diameters, and hammers. This research provides a comprehensive engineering framework for evaluation of culvert installations at the planning phase to address the gaps in knowledge associated with pipe ramming.
Presently there are no existing and proven techniques for prediction of settlement, vibration, driving stresses, soil resistance to ramming, and drivability for pipe ramming installations. This study has adopted existing drivability, soil resistance, settlement, and vibration prediction models from pipe jacking, microtunneling, and pile driving models and examined their applicability in pipe ramming installations, resulting in new and technology-specific design guidance. The development of this comprehensive engineering guidance is based on engineering calculations empirically tuned using a database of actual performance measurements. Field observations of five production installations and a full-scale experiment were conducted to form the performance database employed to understand the mechanics associated with pipe ramming installations, ranging from vertical ground movements, ground vibrations, and installation performance.
Settlement prediction was evaluated using the inverted normal probability distribution based models, and these methods over-estimated the observed settlements close to the center of the pipes and under-estimated settlements at radial distances away from the pipe. A pipe-ramming-specific hyperbolic model was developed for better prediction of the vertical settlement induced by pipe ramming in granular soils. Attenuation of observed pipe ramming-induced vibrations was modeled using a simple semi-empirical approach, and the calibrated model resulted in reasonable predictions of the ground vibrations for granular soils. The static soil resistance to ramming was evaluated using the traditional quasi-static pipe jacking models and the models resulted in inaccurate predictions for instrumented pipe ramming installations. Therefore pipe ramming-specific static soil resistance models were developed for both the face and casing resistance in granular soils. Principles of stress wave theory routinely applied in the drivability analyses for pile foundations were adopted for the evaluation of the dynamic response pipes during ramming. Reliable estimates of the static soil resistance and dynamic soil parameters were obtained through signal matching processes. Data-informed drivability analysis were performed to simulate the magnitude of driving stresses and develop drivability curves which relate the penetration resistance of a given pipe and hammer to the range of static soil resistances. The study culminates in the first comprehensive framework and recommendations for the installation of pipes by ramming, and should help owners, consultants, and contractors to appropriately plan pipe ramming installations. / Graduation date: 2013
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Interpreting wave propagation in a homogeneous, isotropic, steel cylinderStoyko, Darryl Keith 12 January 2005 (has links)
The majority of commercially available ultrasonic transducers used to excite and measure wave propagation in structures can be coupled only to a free surface. While convenient, this method is likely to excite multiple structural modes, making data interpretation difficult. Furthermore, the many modes excited make predicting the structure’s response a computationally intensive task. Here the dynamic radial displacement induced by a transient radial point load is calculated at more than 230,000 points on the outer surface of a virgin steel pipe to simulate a typical experiment. The radial component of the displacement field is calculated by convolving the Green’s functions of the pipe with the transient load. These functions are calculated on personal computers (in a distributed arrangement) by employing modal summation. The mode shapes are obtained from a Semi-Analytical Finite Element formulation used in conjunction with a separation of variables. The results are presented in a four dimensional animation, providing easier interpretations and insight into how to best select observation points for the detection of defects. The accuracy of the calculated displacements is verified experimentally. Agreement is good when magnitude and phase corrections are incorporated from the frequency response curves of the transducers used. / February 2005
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The Investigation of Guided Wave on Elbow Pipe with DefectDu, Guan-hung 16 September 2012 (has links)
It is usually to see a large number of pipelines separating around the refineries, chemical and petro-chemical plants. The corrosion and erosion defects are unavoidable to occur in transporting pipe line. Especially, the maintain stuff usually find out breakage pipe or leaking liquid at elbowing pipe line because of the corrosion and erosion defects. So it is essential to examine these pipelines with an efficient method. The use of guided waves method is very attractive to solve this problem since guided wave could be excited at one circle on the pipeline and propagate over considerable distance. To choose guided wave torsion mode T (0, 1) as excitation mode because its group velocity doesn¡¦t change with frequencies. And the research analyzes the mode conversion that occurred when T (0, 1) mode propagated after the elbow pipe. The research also discusses the signal difference in different depth, circumferential distribution and axial length defects on the elbow pipe.
The erosion defect usually occurs in the elbow pipe line and it would change with fluid velocity, causticity of fluid and flow direction. Therefore, the research designs the defects according to the character of erosion defect by finite element method software and simulates T (0, 1) mode propagating in the pipe line. Then this research extracts and analyzes the reflection signals from defects. In this guided wave experiment, the research manufactures the defect on elbow pipe. Because the erosion defect could be usually found at outer side of elbow pipe, artificial defect would be set there. And the elbow pipe is manufactured with different depth, circumferential distribution and axial length defect.
The research would discuss the relationship between change of defect and reflection signal. By elbow pipe defect signals of simulation and experiment consequence, the different depth, circumferential distribution and axial length defect signals could be still distinguished. The signals with different axial length defect that received from straight pipe and elbow pipe are similar and are affected by signal constructive and destructive interference. So the research could get maximum and minimum defect signal amplitudes from one-fourth wavelength axial defect and half wavelength axial defect. Therefore, the axial length defect of elbow pipe could be estimated from defect signals and this consequence could help judge the level of damaged elbow pipe. T (0, 1) mode has better sensitivity to outside of the pipe than inside of the pipe. So the bigger signal amplitude could be received from the notch at outside of the pipe. In the process of wave propagation simulation, there are overlapping waveforms and mode conversions occur at elbow pipe. This situation causes the defect signals were amplified at elbow pipe. In practical detection, the misjudgments of amplified defect signals should be attended to.
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Investigation of Swirl Flows Applied to the Oil and Gas IndustryRavuri Venkata Krish, Meher Surendra 16 January 2010 (has links)
Understanding how swirl flows can be applied to processes in the oil and gas industry and how problems might hinder them, are the focus of this thesis. Three application areas were identified: wet gas metering, liquid loading in gas wells and erosion at pipe bends due to sand transport. For all three areas, Computational Fluid Dynamics (CFD) simulations were performed. Where available, experimental data were used to validate the CFD results. As a part of this project, a new test loop was conceived for the investigation of sand erosion in pipes.
The results obtained from CFD simulations of two-phase (air-water) flow through a pipe with a swirl-inducing device show that generating swirl flow leads to separation of the phases and creates distinct flow patterns within the pipe. This effect can be used in each of the three application areas of interest.
For the wet gas metering application, a chart was generated, which suggests the location of maximum liquid deposition downstream of the swirling device used in the ANUMET meter. This will allow taking pressure and phase fraction measurements (from which the liquid flow rate can be determined) where they are most representative of the flow pattern assumed for the ANUMET calculation algorithms.
For the liquid loading application, which was taken as an upscaling of the dimensions investigated for the wet gas metering application, the main focus was on the liquid hold-up. This parameter is defined as the ratio of the flowing area occupied by liquid to the total area. Results obtained with CFD simulations showed that as the water rate increases, the liquid hold-up increases, implying a more effective liquid removal. Thus, it was concluded that the introduction of a swirler can help unload liquid from a gas well, although no investigation was carried out on the persistance of the swirl motion downstream of the device.
For the third and final application, the erosion at pipe bends due to sand transport, the main focus was to check the erosion rate on the pipe wall with and without the introduction of a swirler. The erosion rate was predicted by CFD simulations. The flow that was investigated consisted of a liquid phase with solid particles suspended in it. The CFD results showed a significant reduction in erosion rate at the pipe walls when the swirler was introduced, which could translate into an extended working life for the pipe. An extensive literature review performed on this topic, complemented by the CFD simulations, showed the need for a dedicated multiphase test loop for the investigation of sand erosion in horizontal pipes and at bends. The design of a facility of this type is included in this thesis.
The results obtained with this work are very encouraging and provide a broad perspective of applications of swirl flows and CFD for the oil and gas industry.
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Heat transfer characteristics of a two-pass trapezoidal channel and a novel heat pipeLee, Sang Won 02 June 2009 (has links)
The heat transfer characteristics of airflows in serpentine cooling channels in
stator vanes of gas turbines and the novel QuTech® Heat Pipe (QTHP) for electronic
cooling applications were studied. The cooling channels are modeled as smooth and
roughened two-pass trapezoidal channels with a 180° turn over a range of Reynolds
numbers between about 10,000 and 60,000. The naphthalene sublimation technique and
the heat and mass transfer analogy were applied. The results showed that there was a
very large variation of the local heat (mass) transfer distribution in the turn and
downstream of the turn. The local heat (mass) transfer was high near the end wall and
the downstream outer wall in the turn and was relatively low in two regions near the
upstream outer wall and the downstream edge at the tip of the divider wall in the turn.
The variation of the local heat (mass) transfer was larger with ribs on two opposite walls
than with smooth walls. The regional average heat (mass) transfer was lower in the turn
and higher in the entire channel with the flow entering the channel through the larger
straight section than when the flow was reversed. The pressure drop across the turn was higher with the flow entering the channel through the larger channel than when the flow
was reversed.
Thermal performance of the QuTech® Heat Pipe was identified over a range of
inclination angles between 90° and -90° and thermal mechanism of the QTHP was
studied with GC-MS, ICP-OES, XRD, XPS, and DSC. This study resulted in the
following findings: the performance of the QTHP was severely dependent on gravity; the
QTHP utilizes water as working fluid; there were inorganic components such as Na, K, P,
S, and Cr, etc.; and the vaporization temperature of the working fluid (mostly water) was
lower than the boiling temperature of pure water. This was due to the presence of
inorganic salt hydrates in the QTHP. It may be concluded that thermal performance of
heat pipes increases with additional latent heat of fusion energy and energy required to
release water molecules from salt hydrates.
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An Analysis of Off-grid, Off-pipe Housing in Six U.S. ClimatesMalhotra, Mini 2009 December 1900 (has links)
This dissertation addresses the issues of climate change and depletion of non-renewable resources of energy and water, and aims at eliminating the use of non-renewable resources of energy and water for the building operation in single-family detached residences in the U.S. With this aim, this study investigated the feasibility of the off-grid, off-pipe design approach in six climate locations across the U.S. to achieve self-sufficiency in a house for building energy, indoor water use, and household wastewater and sewage disposal using only on-site available renewable resources.
For the analysis, a 2,500 ft2, 2000/2001 International Energy Conservation Code standard reference house with typical building and usage characteristics was selected as the base case. The six U.S. climate locations included: Minneapolis, MN, Boulder, CO, Atlanta, GA, Houston, TX, Phoenix, AZ, and Los Angeles, CA. The renewable resources considered for this study included: solar radiation, wind, biomass for building energy needs; rainwater for indoor water use. In addition, the building site was considered for the disposal of household wastewater and sewage. The selected climate locations provided different scenarios in terms of base-case building energy needs and availability of renewable resources. Depending on these, energy and water efficiency measures were selected for reducing the building needs. For the reduced building needs, the sizing of systems for self-sufficiency was performed, including: solar thermal system for building’s space heating and water heating needs, photovoltaic and wind power systems for building’s electricity needs; rainwater harvesting system for indoor water needs; and septic system for the on-site disposal of household wastewater and sewage. In this manner, an integrated analysis procedure was developed for the analysis and design of off-grid, off-pipe homes, and was demonstrated for six U.S. climate locations.
The results of the analysis indicated that achieving self-sufficiency for energy, water and sewage disposal was possible is all climates provided the systems for the collection and storage of renewable resources were large. On the other hand, the utilization of these systems was small for locations, where the year-to-year and seasonal variations in the weather conditions and availability of climate resources was large. For increased system utilization, minimization of the peak building needs, utilization of harvested energy for secondary purposes, and considering alternative systems for such applications are preferred.
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Phpa As A Frictional Pressure Loss Reducer And Its Pressure Loss EstimationErcan, Can 01 June 2007 (has links) (PDF)
As the demand of oil and gas is increasing, using the existing reservoirs more efficiently as well as searching for new reservoirs is mandatory. Most undiscovered reservoirs are in deep or ultra-deep offshore locations, where drilling to such targets are very difficult with the available fluid circulation technology, since there exists a significant frictional pressure loss due to extreme long wellbores. In order to reduce the frictional pressure losses inside the drillstring, frictional drag reducers are used. Frictional drag reducers are mostly high molecular weight linear polymer molecules and can be used with water or hydrocarbon based solvents. The system used in this study is Baroid EZ-Mud water solutions. Baroid EZ-Mud is a liquid polymer emulsion containing partially hydrolyzed polyacrylamide / polyacrylate (PHPA) co-polymer.
This study aims to observe the performance of EZ-Mud as a frictional drag reducer. For this purpose, a flow loop that consisted of a circular pipe where the frictional pressure losses can be observed under various flow rates and concentrations is developed.
Pipe flow experiments were performed using water-based mud generated using different concentrations of Baroid EZ-Mud at different flow rates. Differential pressure values were recorded for each run. Rheological properties of each mud sample were determined using Fann (Couette) viscometer in order to determine the theoretical frictional pressure losses. Theoretical and measured frictional pressure losses were compared. Results showed that, as the concentration of EZ-Mud was increased, considerable frictional drag reduction as high as 60% was observed.
Based on the experimental data obtained from the flow loop using EZ-Mud with different concentrations, a friction factor correlation as a function of Reynolds Number and EZ-Mud concentration is developed. The proposed correlation performance was also compared with the existing correlations from the literature. It has been observed that, frictional pressure losses using the developed friction factor could be estimated within an error range of maximum 15 %, whereas, the existing models could not predict frictional pressure losses as accurate as the proposed model.
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A Comparative Investigation Of Heat Transfer Capacity Limits Of Heat PipesKucuk, Sinan 01 December 2007 (has links) (PDF)
Heat pipe is a passive two phase device capable of transferring large rates of heat with a minimal temperature drop. It is a sealed tube with a wick structure lined in it and with a working fluid inside the tube. It consists of three parts: an evaporator, a condenser and an adiabatic section. The heat pipes are widely used in electronics cooling and spacecraft applications. Although they can transfer large rate of heat in a short range, they have operating limits, namely: the capillary limit, the viscous limit, the entrainment limit, the sonic limit and the boiling limit. These limits determine the heat transfer capacity of the heat pipe. The properties of the working fluid, the structure of the wick, the orientation of the pipe, the length and the diameter of the tube etc. are the parameters that affect the limits. In this study, an analytical 1-D heat pipe model is formed and a computer code is prepared in order to analyze the effects of the parameters on the heat transfer capacity of a heat pipe. Water, Ammonia and Mercury are investigated as working fluids for different operating temperature ranges. The software is tested for a typical application for each working fluid.
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