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Fischdick Acuna, Andres FabricioHybrid Laser Welding in API X65 and X70 Steels
Master of Science, The Ohio State University, 2016, Materials Science and Engineering
Hybrid laser welding presents an important advance in productivity due to high welding speeds. However, fast cooling rates are inherent to the process, affecting the resultant microstructures and joint performance. In this research, three API steels were welded using hybrid laser welding with three distinct preheating conditions. The specimens, which were obtained using one hybrid laser root pass and two other GMAW filling passes, were subjected to microstructural characterization and performance evaluation using hardness and toughness measurements. Incomplete joints with only the hybrid root pass and completed joints (root and filling passes) were evaluated. Hardness mapping revealed as the critical area the top portion of hybrid laser fusion zone, which was subsequently reheated by the GMAW filling pass. Optical and scanning electron microscopy revealed a bainitic-martensitic microstructure with the proportion of those two phases varying as a function of the preheating. Miniaturized Charpy V-notch testing was used to evaluate the local toughness and ductile-to-brittle transition of several regions within the joint. Fractographic analysis confirmed the abrupt transition from ductile-to-brittle behavior. The localized fracture toughness testing showed an adequate joint performance for all tested conditions. Nevertheless, the hardness values meet the requirements only for higher preheating temperature conditions.

Committee:

Antonio Ramirez (Advisor); John Lippold (Committee Member)

Subjects:

Engineering; Materials Science; Metallurgy; Petroleum Engineering

Keywords:

Hybrid Laser, Pipeline, GMAW, HLAW, Steel, Hardness, Toughness, KLST, MCVN, Miniaturized Charpy, Ductile-to-Brittle Transition Temperature, DBTT, Bainite, Martensite

Schaser, Matt SaxonMaterial Specific Load Combination Factors for Option 2 FAD Curves
Master of Science in Engineering Mechanics, Cleveland State University, 2013, Fenn College of Engineering
The use of failure assessment diagrams (FAD) for evaluating the integrity of components containing crack-like flaws has developed a well-defined methodology over the years that includes a correction factor to account for combined loading effects that are a result of primary and secondary stresses. The load combination factor, Ψ, is based on the Option 1 FAD currently in use in the Central Electricity Generating Board’s (CEGB) report No. R/H/R6 (R6) and the API-579-1/ASME FFS-1 fitness-for-service standard. The Ψ factors for the Option 2 FAD based on ASME B&PV Code Section VIII, Division 2 material stress-strain curves are developed and tabulated here for a wide range materials used for the construction of pressure vessels. The Ψ factors based on the Option 1 FAD are recalculated here and compared to current published data. The approach utilizing Option 1 FAD methods is evaluated here with regard to its conservatism and applicability to material models other than the Ramberg-Osgood model. In addition, a sensitivity analysis is performed to estimate Ψ factor errors due to uncertainty in material property parameters. A critical review of the tabulated data in API-579 is performed and errors are identified along with suggested solutions to correct the data.

Committee:

Stephen Duffy, PhD (Committee Chair); Paul Lin, PhD (Committee Member); Norbert Delatte, PhD (Committee Member)

Subjects:

Engineering; Materials Science; Mechanical Engineering; Metallurgy; Nuclear Engineering; Petroleum Engineering

Keywords:

Failure Assessment Diagram; FAD; Load Combination Factor; FFS; Fitness-for-Service; Fitness for Service; Psi Factor; Phi Factor; API-579; API-579-1; ASME FFS-1; Prager Stress Strain Model; Prager Stress-Strain Model; Crack-like Flaw

Balagurunathan, JayakishanInvestigation of Ignition Delay Times of Conventional (JP-8) and Synthetic (S-8) Jet Fuels: A Shock Tube Study
Master of Science (M.S.), University of Dayton, 2012, Mechanical Engineering
The global depletion of petroleum-based fuels has led the world to more closely examine alternate fuels. Therefore, alternate fuels produced from feedstocks such as coal, soybeans, palm oil or switch grass through methods such as coal liquefaction, biomass gasification, and Fischer-Tropsch synthesis have been tested. Among these techniques, fuels generated using Fischer-Tropsch technologies are of interest because they produce clean burning hydrocarbons similar to those found in commercial fuels. Therefore, in this study the Fischer-Tropsch derived S-8 fuel was evaluated as a drop-in replacement for the jet fuel JP-8. The jet fuel JP-8 is comprised of n-, iso- and cyclo- alkanes as well as aromatics while the S-8 fuel is primarily comprised of n- and iso- alkanes. The composition of the fuel affects its ignition characteristics chemically and physically by either advancement or delay of time to ignition. Since this study focused on the chemical effects, the fuels were completely pre-vaporized and pre-mixed. A high pressure, high temperature heated single pulse shock tube was used for this study. The shock tube is an established experimental tool used to obtain ignition delay data behind reflected shock waves under operating conditions relevant to modern engines. The experiments were conducted over a temperature range of 1000-1600 K, a pressure of 19±2 atm, equivalence ratios of 0.5, 1 and 3, within a dwell time of 7.6±0.2 ms and an argon dilution of 93% (v/v). Ignition delay times were measured using the signal from the pressure transducer on the end plate with guidance from the optical diagnostic signal. Along with JP-8 and S-8, the ignition delay of n-heptane was also studied. N-heptane was chosen to represent the n-alkanes in the fuels for this study since it was present in both fuels and also to prove the fact that the n-alkanes were rate controlling. The results indicate that both S-8 and JP-8 fuels have similar ignition delays at corresponding equivalence ratios. The fuel-rich mixtures ignited faster at lower temperatures (<1150 K) and the fuel-lean mixtures ignited faster at higher temperatures (>1150 K). In the transition period between lower to higher temperatures (~1100-1200 K), the equivalence ratio had no significant effect on the ignition delay time. The results also show that the ignition delay time measurements of S-8 and JP-8 fuels are similar to the ignition delay of n-heptane at the equivalence ratio of Φ=0.5 and thereby indicate that the n-alkanes present in these fuels controlled the ignition under these conditions. The ignition delay results of S-8 and JP-8 at Φ=3.0 from this study were also compared to prior work (Kahandawala et al., 2008) on 2-methylheptane and n-heptane/toluene (80/20 liquid vol.%), respectively and found to be indistinguishable. This data serves to extend the gas phase ignition delay database for both JP-8 and S-8 and is the first known data taken for both these fuels at higher temperatures (>1000 K) for an equivalence ratio of 3.0 with argon as the diluent gas.

Committee:

Sukh Sidhu, Dr (Committee Chair); Philip Taylor, Dr (Committee Member); Moshan Kahandawala, Dr (Committee Member)

Subjects:

Aerospace Engineering; Aerospace Materials; Alternative Energy; Automotive Engineering; Automotive Materials; Chemical Engineering; Chemistry; Energy; Engineering; Environmental Engineering; Mechanical Engineering; Petroleum Engineering; Technology

Keywords:

Ignition delay; shock tube; S-8; JP-8; Jet fuels; Fuel characteristics; heated shock tube; Fischer-Tropsch; Alternate fuels; alkanes; synthetic fuel; fuel; iso-alkanes; jayakishan balagurunathan

Emami, FatemesadatThermodynamically Consistent Interatomic Potentials for Silica to Design Specifically Binding Peptides: Role of Surface Chemistry, PH, and Amino Acid Sequence
Doctor of Philosophy, University of Akron, 2013, Polymer Engineering
Silica is commonplace in many industrial and laboratory-scale applications. However, control over the morphology of the silica particles has remained a major challenge. Nature exhibits examples of highly ornate silica-based materials produced under benign environmental conditions. For instance, marine microorganisms are able to condense silicic acid in-vivo in the presence of specific polypeptides and create a hierarchical siliceous frustule. Hence understanding the interactions of biological molecules in contact with silica can revolutionize the fabrication of tailored silica-based materials for specific applications. In this project, we pursued a systematic study of experimental and computational approaches to explain specific adsorption of peptides on silica particles. Silica surfaces exhibit sensitive surface chemistry with variable densities of silanol and siloxide groups depending on synthetic routes, pH, ionic strength, nanoparticle size, and other chemical and thermal treatments. In first approximation, amorphous silica can be described by Q3-type surfaces with approximately 4.7 silanol groups per square nanometer from which 0 to 20% are ionized depending on solution pH and ionic strength. We introduce a suite of models that captures realistic surface morphology and chemical functionality of silica in various chemical environments. Further, thermodynamically consistent intermolecular potentials compatible with common force fields such as CVFF, CHARMM, AMBER, PCFF, and COMPASS are presented. Bulk and interfacial properties including X-ray structure, IR-spectrum, density, heat of immersion, surface pressure, and surface wettability are reproduced in comparison to available experimental data. Experimental results of screening phage libraries on amorphous silica particles (biopanning experiment) show that peptides recognize the surface chemistry of the particles. Increasingly basic peptides preferred increasingly acidic silica particles, the surface structure of which was quantified by zeta potential measurements and acid-base titration. Subsequent examination of adsorption of the selected peptides by fluorometric assay and infrared spectroscopy followed by extensive molecular dynamics simulations indicated a distinct binding mechanism for cationic and non-cationic peptides. Positively charged peptides were strongly attracted to the particles by ion pairing of the positively charged moieties with surface siloxide groups. Adsorption levelled off at higher peptide concentration due to a rise in peptide-peptide electrostatic repulsion and possible reversal of the zeta potential. Non-cationic peptides were less strongly attracted to the particles by intermittent hydrogen bonds. Further, hydrophobic moieties tended to stay in the proximity of the surface due to exclusion from water with a strong hydrogen bond network. Point mutation of steric-restraining residues from the middle and end of the peptide showed significant change in the peptide conformation and binding. Peptide adsorption was also studied as a function of pH and particle size. The negative surface charge of silica increases at higher pH so that positively charged peptides are more strongly and negatively charged peptides less strongly recognized. Larger particles are more acidic at the interface, which can also alter the binding mechanism. Comparison of detected cross peaks of NOES by NMR experiment and inter-nuclear distances obtained from the simulation further confirms that molecular simulation with the new potentials is suited to monitor and predict conformations of peptides and other organic on aqueous silica surfaces.

Committee:

Hendrik Heinz, Dr. (Advisor); Jutta Luettmer-Strathmann, Dr. (Committee Member); Thein Kyu, Dr. (Committee Member); Ali Dhinojwala, Dr. (Committee Member); Younjin Min, Dr. (Committee Member); Jie Zheng, Dr. (Committee Member)

Subjects:

Chemical Engineering; Chemistry; Molecular Biology; Molecular Chemistry; Molecular Physics; Petroleum Engineering; Pharmaceuticals; Pharmacy Sciences; Physics; Polymer Chemistry; Polymers

Babic, MarijanRole of Interfacial Chemistry on Wettability and Carbon Dioxide Corrosion of Mild Steels
Doctor of Philosophy (PhD), Ohio University, 2017, Chemical Engineering (Engineering and Technology)
Internal corrosion of oil and gas pipelines made from mild steel is a commonly encountered problem in the oil and gas industry. It is frequently associated with the presence of water that wets the steel surface and carbon dioxide which produces corrosive species in a water phase. This study addresses four aspects related to the role of interfacial chemistry on wetting and corrosion: • Effect of crude oil foaming on corrosion inhibition. • Effect of oil on foams produced by corrosion inhibitors and subsequent corrosion inhibition. • Effect of ionization of naturally present crude oil compounds on wetting and corrosion inhibition. • Effect of residual carbide corrosion products on steel wettability and wetting. The effect of crude oil foaming on corrosion inhibition was investigated with model compounds chosen to represent polar compounds in real crudes with dual foam-forming and corrosion inhibition properties; the investigations were performed in a small scale experimental apparatus. It was found that corrosion inhibition properties of oils were unaffected by the foaming process. The effect of oil on inhibitor-induced foaming was studied in small scale tests with an imidazoline-type corrosion inhibitor and two oils of different chemical composition. The results showed that the hydrocarbon oil can suppress foam generation, effectiveness of corrosion inhibitor can be partially preserved when the layer of oil is in the contact with a foaming aqueous solution. The influence of pH on corrosion inhibition by polar crude oil compounds on their corrosion inhibition and wetting properties was determined using a model oil. Experiments were again performed using an in-house designed and built apparatus for wetting measurements in dynamic conditions. It was shown that pH can significantly alter the corrosion and wetting properties of steel by ionizing crude oil polar compounds. In the last segment of the study the wettability of corroded surfaces was investigated. It was found that carbide layers were more hydrophobic compared to the initial steel surface. However, the water which stays entrapped within the porous carbide layer creates confined aqueous environments that have the potential to significant affect corrosion.

Committee:

Srdjan Nesic (Advisor)

Subjects:

Chemical Engineering; Chemistry; Petroleum Engineering

Keywords:

pipeline; mild steel; crude oil; hydrocarbon; water; carbon dioxide; corrosion; multiphase flow; wetting; wettability; inhibition; contact angle; foam; defoaming; polar compounds; pH; cementite;

Ghanbarian-Alavijeh, BehzadModeling Physical and Hydraulic Properties of Disordered Porous Media: Applications from Percolation Theory and Fractal Geometry
Doctor of Philosophy (PhD), Wright State University, 2014, Environmental Sciences PhD
A fundamental component of the hydrologic cycle is the movement of fluids in the pore space of geological formations and soils. Prediction of the motion of fluids in such porous materials requires first modeling the physical properties of the medium itself, and second, invoking a capable theory to describe fluid transport in tortuous interconnected pathways. In this dissertation, for the former we use fractal geometry since most phenomena in nature are fractal, and for the latter percolation theory is applied because it has successfully described flow and transport in disordered networks and media. We propose models for the soil water retention curve and tortuosity. We also focus on modeling different kinds of transport, such as air permeability, gas and solute diffusion, unsaturated hydraulic conductivity, and dispersion. Applications of critical path based analyses of flow and conduction properties reveals asymmetry between the saturation dependence of the air and water permeabilities as well as distinctions between the electrical and hydraulic conductivities. In particular, the saturation dependence of the hydraulic conductivity is strongly dependent on the pore size distribution, but that of the electrical conductivity is only weakly so, and the air permeability is not dependent. Gas diffusion relates more closely to the air permeability, while solute diffusion is, under a wide range of circumstances, tied directly to the electrical conductivity. Comparisons with experiment confirmed this. Applying critical path analysis and universal scaling from percolation theory to media that could be treated within the pore-solid fractal (PSF) approach, we developed unimodal and bimodal models for unsaturated hydraulic conductivity in porous media. Predictions were developed for unsaturated hydraulic conductivity using the soil water retention curve. To evaluate our unimodal model we used 104 experiments from the UNSODA database and compared with two other models. The results obtained indicated that our non-universal percolation based model predicted unsaturated hydraulic conductivity better than the other two models. In order to evaluate the bimodal models for soil water retention and unsaturated hydraulic conductivity curves, we compared them with 8 measured experiments collected from the UNSODA database. Although the bimodal unsaturated hydraulic conductivity model was fitted well to the experiments, we found discrepancy between measurements and predictions. We found that the predictions were relatively more successful for the first regime at large water contents than the second regime at low water contents. The universal scaling law from percolation theory was confirmed for the saturation dependence of the air permeability. Analyzing two independent databases including 39 experiments showed that the experimental exponent was 2.028 ± 0.028 and 1.814 ± 0.386 for the first and second databases, respectively. We found the extracted exponent in the power law fit is most sensitive to the measured values of the air permeability at low values of the air-filled porosity, and in cases where these experimental values are missing, the data can yield values significantly different from 2. We also found that the threshold value of the air-filled porosity could be predicted reasonably from the wet end of the soil water retention curve. Diffusion modeling in percolation clusters provided a theoretical framework to address gas and solute transport in porous media. Theoretically, above the percolation threshold, the saturation dependence of gas and solute diffusion should follow universal scaling from percolation theory with an exponent of 2.0. In order to evaluate our hypothesis, we used 71 and 106 gas and solute experiments, respectively, including different types of porous media available in the literature. Although our results conclusively confirmed the universality of gas diffusion, we found scatter in solute diffusion data. Nonetheless, the experimental exponent of solute diffusion was very close to 2 (1.842). We found that combining percolation and effective medium theories resulted in an accurate numerical prefactor for both gas and solute diffusion. We also developed a saturation dependence model for dispersion. Based on concepts from critical path analysis, cluster statistics of percolation, and fractal scaling of percolation clusters we derived an expression for the characteristic velocities along different pathways through the network. We compared our theoretical framework for solute transport with two experimental databases. Our model evaluation with experiments indicated excellent results. In the first dataset, we fitted our model to the arrival time distribution calculated from the measured breakthrough curve at saturation and determined the model parameters. Then those parameters were used to predict the arrival time distribution at two other saturations, giving an excellent match with the measurements. In the second dataset, the arrival time distribution was predicted from the measured soil water retention curve. Our results indicated that we predicted the arrival time distribution very well for 5 unsaturated experiments.

Committee:

Allen Hunt, Ph.D. (Advisor); Thomas Skinner, Ph.D. (Advisor); Muhammad Sahimi, Ph.D. (Committee Member); Robert Ritzi, Ph.D. (Committee Member); Chao Chen Huang, Ph.D. (Committee Member)

Subjects:

Agricultural Engineering; Agriculture; Chemical Engineering; Civil Engineering; Environmental Engineering; Environmental Science; Fluid Dynamics; Geological; Geology; Geophysical; Geophysics; Hydrologic Sciences; Hydrology; Petroleum Engineering; Physics; Soil Sciences; Theoretical Mathematics

Keywords:

Percolation theory, Fractals, Porous media, Dispersion, Unsaturated hydraulic conductivity, Air permeability, Diffusion, Tortuosity, Saturation dependence, Pore-size distribution

Kurtz, Aaron DDetermining Mineralogy from Traditional Well Log Data
Bachelor of Science in Petroleum Engineering, Marietta College, 2013, Petroleum Engineering and Geology
It has been hypothesized that utilizing current well logging practices, with Dual Water Theory, it is possible to identify all minerals within rock formations. The purpose of this study was to develop software that supports this hypothesis. It also was created to demonstrate a hypothesized plotting correlation discovered by Professor Ben Ebenhack. The results show promise in supporting this hypothesis correct, and recommendations for future adjustments to the software are given.

Committee:

Ben Ebenhack (Advisor); Robert Van Camp (Committee Member); David Brown (Committee Member)

Subjects:

Petroleum Engineering; Petroleum Geology

Keywords:

Dual Water Theory; Density; mineral composition; formation evaluation; quartz; shale; effective porosity; porosity; gamma ray; software

Kondaveeti, RajivImpact of Halogenated Aliphatic and Aromatic Additives on Soot and Polycyclic Aromatic Hydrocarbons -- An Ethylene-air Laminar Co-flow Diffusion Flame Study
Master of Science (M.S.), University of Dayton, 2012, Mechanical Engineering

The objective of this study is to investigate the effects of aliphatic and aromatic halogenated additives on soot and PAH formation (polycyclic aromatic hydrocarbon) using a laminar co-flow ethylene-air diffusion flame. Both aliphatic surrogates (bromobutane, chlorobutane and bromo/chlorobutane mix) and aromatic surrogates (benzene, bromobenzene, chlorobenzene and bromo/chlorobenzene mix) were added to the base fuel for investigation. The soot particles were collected on quartz filters and their mass was determined using a Leco carbon burn-off method. The gaseous effluents were collected in an Amberlite XAD-2 sorbent trap and extracted using the Soxhlet technique. Gas chromatography / mass spectrometry (GC/MS) was used to identify and quantify the extracted gaseous effluents. Significant amounts of enols were detected along with PAHs, indicating that enols are also important intermediate species in hydrocarbon combustion.

The results showed that all the halogenated additives reduced the temperature of the sampling system, indicating flame suppression properties. All the additives gave increased soot yields when compared to the baseline experiment. The brominated fuel additives displayed a higher propensity to soot than the corresponding chlorinated fuel additives. The aromatic additives showed a greater tendency to soot than their aliphatic counterparts. All the additives increased the total PAH and enol yields, with benzene yielding the highest. The halogenated form of benzene decreased the total PAH and enol yields when compared to benzene, suggesting that halogens accelerate the conversion of PAHs to soot. The effect of bromine in increasing the total PAH and enol yields is more than that of chlorine.

Committee:

Dr. Sukh Sidhu (Committee Chair); Dr. Philip Taylor (Committee Member); Dr. Moshan Kahandawala (Committee Member)

Subjects:

Aerospace Engineering; Analytical Chemistry; Automotive Engineering; Chemical Engineering; Chemistry; Engineering; Environmental Engineering; Mechanical Engineering; Organic Chemistry; Petroleum Engineering

Keywords:

Co-Flow Ethylene-Air Diffusion Flame; Flame retardants; Halogenated additives; Brominated; Chlorinated; Benzene; Chlorobenzene; Bromobenzene; Chlorobutane; Bromobutane; Bromochloro mixtures; Emissions; Soot; PAHs; Polycyclic Aromatic Hydrocarbons; Enols

Jauseau, NicolasMultiphase Flow Effects on Naphthenic Acid Corrosion of Carbon Steel
Doctor of Philosophy (PhD), Ohio University, 2012, Chemical Engineering (Engineering and Technology)
Because of increasing oil prices and the continuous need for improving business margins, the refining industry faces new challenges by processing cheaper oils, such as "opportunity crudes". These usually contain higher amounts of corrosive sulfur compounds and naphthenic acids (NAP) which, at high velocity multiphase flow conditions, can impair the integrity of transfer lines in crude distillation units. Previous studies have shown that NAP corrosion is particularly aggressive in the presence of a liquid phase at the metal surface. Although the effect of flow was previously assessed in single-phase flow conditions, a high velocity multiphase flow has been suggested to occur in the transfer lines. Therefore, this study investigates the multiphase flow effect on NAP corrosion of carbon steel in the presence or absence of an iron sulfide corrosion product layer, at elevated temperature and fluid flow velocities, using a small-scale annular flow rig (AFR). In parallel, it examines the hydrodynamics of a multiphase flow mixture at room temperature and high flow velocities in a large-scale cold flow rig (CFR), in order to identify the flow patterns and their characteristics. A mechanistically derived gas-liquid two-phase flow model is additionally developed to predict the flow regimes and related characteristics, and for its application to the operating conditions in the AFR to understand what may control the NAP corrosion rate. Results show a multiphase flow effect on the NAP corrosion rate at superficial gas velocities in the range of 1–10 m/s, where a decrease in the corrosion rate by 60% occurred at a constant liquid velocity of 0.1 m/s and a total acid number of 2 mg KOH / g oil. The iron sulfide scale built during sulfidation conferred some protection in single phase flow, but none in multiphase flow. The main predicted flow patterns were: annular, stratified, intermittent and bubble. The oil wetting is suggested to be the main mechanism controlling pure NAP corrosion in multiphase flow; the dominant pattern in the AFR was most likely a mist flow, leading to lower wetted wall fractions and, consequently, reduced corrosion rates.

Committee:

Srdjan Nesic, PhD (Committee Chair); Valerie Young, PhD (Committee Member); Dusan Sormaz, PhD (Committee Member); Lauren McMills, PhD (Committee Member); Howard Dewald, PhD (Committee Member)

Subjects:

Chemical Engineering; Fluid Dynamics; Materials Science; Petroleum Engineering

Keywords:

naphthenic acid corrosion; multiphase flow; high flow velocity; entrainment of liquid droplets; oil refinery; transfer lines

Aliev, RuslanCFD Investigation of Heat Exchangers with Circular and Elliptic Cross-Sectional Channels
Master of Science in Mechanical Engineering, Cleveland State University, 2015, Washkewicz College of Engineering
Design of the fluid flow and heat transfer components utilizing the Computational Fluid Dynamics (CFD) is relatively new yet cheaper and accurate method that becomes popular and reliable today. In this thesis, design of a heat exchanger using CFD analysis technique is considered. A key investigation of this devise is the selection of the tubes and connection them to inlet and outlet manifolds. Correctly selected tube size and tube cross section impacts the heat exchanger performance. Thermal and hydrodynamic performance of the flow in circular and elliptic tubes connected to the inlet and outlet manifolds have been computationally investigated for maximum Figure of Merit. The tube with high Figure of Merit is the one with high heat transfer rate and low pressure drop. The tube has four different configurations of the cross section: a circular tube and three elliptic tubes with aspect ratios = 0.75, 0.50, and 0.25. All tubes are constrained to have the same wetted perimeter and the length, thus have the same heat transfer area. The tube is a smooth straight tube that has the length of 0.3048 m (12 in.) and wetted perimeter of 0.0798 m (3.1416 in.). The tube wall thickness is negligible. The contribution of the inlet and outlet manifolds is examined. A wide range of Reynolds numbers is covered, Re =100 (laminar flow), 10,000 (transitional flow), and 20,000 (turbulent flow). ANSYS FLUENT commercial code has been utilized in this investigation. The code was validated matching with experimental correlations (for developing hydrodynamic and thermal flow) available in the literature. The CFD simulation results were in agreement with the experimental correlation within 5%. This investigation started with simulating 12 different flow conditions inside the tubes without manifolds: three sets with four different tube options (as stated above) in each set. Each set represents the different flow regime: laminar transitional and turbulent with set Reynold number value, as noted earlier. All CFD simulation results were evaluated for their Figure of Merit (“Goodness” factor). The elliptic tube with aspect ratio = 0.25 showed the highest figure of merit for all cases of Re. In the following stage of this research the results of selected tube (aspect ratio = 0.25) was integrated with inlet and outlet manifolds. In this scenario only laminar and turbulent flow regimes were examined. The contribution of the inlet and outlet manifolds overall resulted a negative effect. The reasons of that impact are the following: (1) the inlet flow condition into the tube is no longer uniform (as was assumed in the earlier study), (2) the pressure drop in the manifolds are significantly higher than that in the tube. and (3) the tube length investigated is short. Despite significantly improved thermal characteristics of the tube flow after adding the manifolds, the magnitude of increased friction factor influenced the value of Figure of Merit.

Committee:

Mounir Ibrahim, PhD (Committee Chair); Majid Rashidi, PhD (Committee Member); Asuquo Ebiana, PhD (Committee Member)

Subjects:

Aerospace Engineering; Automotive Engineering; Mechanical Engineering; Nuclear Engineering; Petroleum Engineering

Keywords:

CFD analysis; circular and elliptic tube flow; heat exchanger; internal fluid flow; heat transfer; internal forced convection; figure of merit

Jin, PengMechanism of Corrosion by Naphthenic Acids and Organosulfur Compounds at High Temperatures
Doctor of Philosophy (PhD), Ohio University, 2013, Chemical Engineering (Engineering and Technology)
Due to the law of supply and demand, the last decade has witnessed a skyrocketing in the price of light sweet crude oil. Therefore, refineries are increasingly interested in "opportunity crudes", characterized by their discounted price and relative ease of procurement. However, the attractive economics of opportunity crudes come with the disadvantage of high acid/organosulfur compound content, which could lead to corrosion and even failure of facilities in refineries. However, it is generally accepted that organosulfur compounds may form protective iron sulfide layers on the metal surface and decrease the corrosion rate. Therefore, it is necessary to investigate the corrosive property of crudes at high temperatures, the mechanism of corrosion by acids (naphthenic acids) in the presence of organosulfur compounds, and methods to mitigate its corrosive effect. In 2004, an industrial project was initiated at the Institute for Corrosion and Multiphase Technology to investigate the corrosion by naphthenic acids and organosulfur compounds. In this project, for each experiment there were two experimentation phases: pretreatment and challenge. In the first pretreatment phase, a stirred autoclave was filled with a real crude oil fraction or model oil of different acidity and organosulfur compound concentration. Then, the stirred autoclave was heated to high temperatures to examine the corrosivity of the oil to different materials (specimens made from CS and 5% Cr containing steel were used). During the pretreatment, corrosion product layers were formed on the metal surface. In the second challenge phase, the steel specimens pretreated in the first phase were inserted into a rotating cylinder autoclave, called High Velocity Rig (HVR). The HVR was fed with a high-temperature oil solution of naphthenic acids to attack the iron sulfide layers. Based on the difference of specimen weight loss between the two steps, the net corrosion rate could be calculated and the protectiveness of corrosion product layer against naphthenic acid corrosion could be assessed. Routinely, the layers generated in pretreatment and challenge phases were investigated with SEM/EDS (Scanning Electron Microscopy/Energy Dispersive Spectroscopy). Selectively, some thin layers formed in the first or second phase were analyzed with FIB-TEM (Focused Ion Beam - Transmission Electron Microscopy). FIB-TEM analysis revealed that there was an iron oxide layer beneath the iron sulfide layer. Experimental results showed that the iron oxide layer was closely related to the layer protectiveness against naphthenic acid corrosion and its formation was due to the presence of naphthenic acids in the fluid. Finally, a new mechanism of naphthenic acid/organosulfur compound corrosion was proposed based on properties of crudes, results of corrosion experimentation, and microscopic analysis of developed surface layers.

Committee:

Srdjan Nesic (Committee Chair); Martin Kordesch (Committee Member); Valerie Young (Committee Member); Eric Masson (Committee Member); Monica Burdick (Committee Member)

Subjects:

Chemical Engineering; Materials Science; Petroleum Engineering

Keywords:

naphthenic acids; high temperature corrosion; organosulfur compound; magnetite; crude fractions; TEM

Kee, Kok EngA Study of Flow Patterns and Surface Wetting in Gas-Oil-Water Flow
Doctor of Philosophy (PhD), Ohio University, 2014, Mechanical Engineering (Engineering and Technology)
Three-phase gas-oil-water flow is a common occurrence in the oil and gas industry. The presence of water in the pipeline can lead to internal corrosion if the free water, dissolved with corrosive species, comes into contact with the wall surface, a scenario known as 'water wetting.' With the introduction of a gas phase, the flow dynamics become much more complicated due to the varying degree of spatial distribution of the immiscible fluids. The present work addresses how the addition of a gas phase to the oil-water flow can change the flow dynamics and surface wetting behavior. The work mainly focuses on the hydrodynamic aspects of the flow and how they may affect the surface wetting in pipe flow. Experimental work was first carried out on oil-water systems to investigate flow patterns and surface wetting behavior in order to establish a baseline for the subsequent measurement of three-phase flow into which CO2 gas was introduced. The experiments were conducted in a large scale 0.1 m ID flow loop. Test fluids used were light model oil LVT200 and 1 wt.% aqueous NaCl. Flow pattern images were visually captured with a high speed video camera and surface wetting behavior was measured using conductivity pins. In oil-water flow, flow patterns can be divided into two broad categories dependent on whether the two immiscible liquids are dispersed or separated. Under those flow conditions, the surface wetting behavior can be categorized into four types of wetting regimes based on the intermittency of the wetting behavior as measured by the conductivity pins. In three-phase gas-oil-water flow, the effects of gas added to the oil-water system were investigated. Flow patterns and surface wetting were quantified at various liquid velocities, gas velocities and water cuts. At low water cut, the wetting results showed that adding the gas phase can help to keep water off the pipe wall, leading to oil wetting. At high water cut, water wetting prevailed and adding gas did not lessen the intensity of wetting. Tomographic techniques were employed to study the cross sectional distribution of the fluid phases in multiphase flow pipes. Knowing the strength and limitations, the techniques can be used for meaningful interpretation of flow patterns. They were not suited, however, for detecting water distribution at low water cut. A mechanistic three-phase water wetting model has been proposed and implemented. The model was built from the framework of the gas-liquid flow model and the oil-water wetting model. The model has been validated with the laboratory data for three different types of flow patterns.

Committee:

Srdjan Nešic, PhD (Advisor)

Subjects:

Chemical Engineering; Fluid Dynamics; Mechanical Engineering; Petroleum Engineering

Keywords:

flow patterns; surface wetting; water wetting; gas-oil-water flow; oil-water flow, three-phase flow; flow loop; conductivity pins; tomography; high speed video camera, predictive model

Wu, XinyangNature of Solid Organic Matters in Shale
Bachelor of Science in Petroleum Engineering, Marietta College, 2013, Petroleum Engineering and Geology
Petroleum industry is always one of the major concerns in everyone's daily life. In recent years, people paid even more attention to the field because human beings are faced with the severe problem of short in oil, or energy resource in general. This paper discuss a specific question on how to category solid carbonate matters in gas-producing shale plays and the reason for the classification. This paper contributes to a better understanding on how oil/gas is stored in shale layers. The goal is to draw a conclusion on whether solid carbonate matters should be considered a portion of pore spaces or rock matrices. Analyzing loggings and other formation evaluation methods are used.

Committee:

Ben Ebenhack (Advisor); Matthew Young, PhD (Committee Member)

Subjects:

Petroleum Engineering

Keywords:

solid carbon; pore space; shale gas

Sander, Zachary HugoHeat Transfer, Fluid Dynamics, and Autoxidation Studies in the Jet Fuel Thermal Oxidation Tester (JFTOT)
Master of Science (M.S.), University of Dayton, 2012, Mechanical Engineering
Modern military aircraft use jet fuel as a coolant before it is burned in the combustor. Prior to combustion, dissolved O2 and other heteroatomic species react with the heated fuel to form insoluble particles and surface deposits that can impair engine performance. For safe aircraft operation, it is important to minimize jet fuel oxidation and resultant surface deposition in critical aircraft components. The Jet Fuel Thermal Oxidation Tester (JFTOT) is a thermal stability test that measures the tendency for fuel to form such deposits and delivers a pass/fail grade for each fuel tested. However, the extent of oxidation and the corresponding deposition occurring in the JFTOT is not fully understood. A JFTOT Model Mark II was modified to include a bulk outlet thermocouple measurement and a downstream oxygen sensor to measure bulk oxygen consumption. Experimental results show a direct relationship between the bulk outlet temperature and JFTOT setpoint temperature with the bulk outlet less than the setpoint temperature. Several fuels were also tested at varying setpoint temperatures with complete oxygen consumption by 320°C and a wide range of oxygen consumption from 10-85% at 260°C. Due to the complex fluid flows in the JFTOT, computational fluid dynamics (CFD) was used to model the heat transfer and fluid flow. A three-dimensional simulation showed considerable recirculation within the JFTOT due to buoyancy effects from gravity and resulted in complex residence time behavior. In addition, CFD simulations performed with a pseudo-detailed chemical kinematic mechanism showed an under prediction in both oxidation and deposition for similar fuels tested experimentally but yielded bulk outlet temperature predictions of less than 2% error. Simulations of deposition were of the right order of magnitude and matched the deposit profile of comparable experimental ellipsometry data.

Committee:

Steven S. Zabarnick, PhD (Committee Co-Chair); Jamie S. Ervin, PhD (Committee Co-Chair); James T. Edwards, PhD (Committee Member)

Subjects:

Aerospace Engineering; Chemical Engineering; Chemistry; Energy; Engineering; Fluid Dynamics; Mechanical Engineering; Petroleum Engineering

Keywords:

JFTOT;CFD; heat transfer; oxidation; autoxidation; deposition; ellipsometry; jet fuel thermal oxidation tester; oxygen consumption; FT; fischer tropsh; hrj; jp-8; jet a-1; thermal stability; fluid mechanics; astm d3241; flir; interferometry; udri

Loegel, Thomas N.High Performance Liquid Chromatography of Petroleum Asphaltenes and Capillary Electrophoresis of Glycosaminoglycan Carbohydrates
Doctor of Philosophy, Miami University, 2012, Chemistry
Separations involving structurally similar high molecular weight compounds have become an important challenge in analytical chemistry. Specific compounds in asphaltenes, the heaviest component of petroleum, have yet to be positively separated and identified. Separation difficulties such as mobile phase and column compatibility force the selection of uncommon solvents and stationary phases. Liquid chromatographic separation of asphaltenes using a cyano-propyl and amino-propyl column with an optimized reverse phase gradient using UV and ¿¿¿¿¿¿¿uorescence as well as mass spectrometry (MS) detection has been demonstrated. The degree of asphaltene aggregation can be followed. Extensive work has determined that the solvent N-methyl-2-pyrrolidinone is a suitable chromatographic solvent but limits the interpretation of MS spectra. The cyano-propyl column is found to be less prone to degradation but the amino-propyl column produced more selective separations. With both columns the molecular weight distribution determined by mass spectrometry is fairly constant, indicating that the retention mechanism is not size-exclusion but more likely partitioning/adsorption. Characterization of different asphaltene samples using the more stable polymeric amino-propyl column is also shown. Improved analytical methods for glucosaminoglycans, such as the anticoagulant heparin, have become quite urgent to prevent any future adulteration cases. Capillary electrophoresis of heparin, dermatan sulfate, and over-sulfated chondroitin sulfate using ethylenediamine as an ion pairing reagent showed a marked change in peak migration order. Other glycosaminoglycans, including chondroitin sulfate and hyaluronic acid, were separated from heparin. Progress toward the characterization of a low cost teaching gas chromatography instrument for the use in a multi-analysis student data collection system has also been made.

Committee:

Neil Danielson, PhD (Advisor); André Sommer, PhD (Committee Chair); Jon Scaffidi, PhD (Committee Member); Richard Taylor, PhD (Committee Member); Paul James, PhD (Committee Member)

Subjects:

Energy; Petroleum Engineering; Petroleum Production

Keywords:

glucosaminoglycans; asphaltenes; PAHs; HPLC; Fuel; Petroleum; Heparin; Gas Chromatography