Transport Phenomena Commons^™

Fluid Transport In Porous Media For Engineering Applications, Eric M. Benner

Chemical and Biological Engineering ETDs

This doctoral dissertation presents three topics in modeling fluid transport through porous media used in engineering applications. The results provide insights into the design of fuel cell components, catalyst and drug delivery particles, and aluminum- based materials. Analytical and computational methods are utilized for the modeling of the systems of interest. Theoretical analysis of capillary-driven transport in porous media show that both geometric and evaporation effects significantly change the time dependent behavior of liquid imbibition and give a steady state flux into the medium. The evaporation–capillary number is significant in determining the time-dependent behavior of capillary flows in porous media. …

Chemical And Physical Modification Of Thiol-Ene And Epoxy-Amine Networks For Advanced Control Of Gas Transport And Flame Retardant Behavior, Vivek Vasagar

Dissertations

Crosslinked polymers are widely used due to its several advantages not limited to high mechanical strength combined with the easy processability. Despite of its popular usage, the fundamental understanding of polymer structure affecting the desired properties is still lacking. This PhD thesis is in two parts, the first part is devoted to the design and developing a basic understanding of structure and chemical composition dependencies of gas transport, whereas in the second part a fundamental relationship between structure to the fire-retardant properties is established.

Membrane based gas separation technique has attracted interest of selective removal of carbon dioxide gas from …

Modeling Of Electrochemical Processes At The Magnesium Anode During Struvite Formation, Tobias Dwyer

Chemical Engineering Undergraduate Honors Theses

This study analyzes the current transients observed during the electrochemical formation of struvite from a solution of ammonium phosphate using a pure magnesium and magnesium alloy electrode. Through converting the chronoamperometric data to chronocoulometric data and fitting the data to various models, the driving mechanisms for struvite nucleation were elucidated. While the pure magnesium anode is controlled by only instantaneous nucleation at the electrode, the AZ31 alloy is nucleation controlled at short times and Cottrell diffusion controlled at long times.

Effects Of Ambient And Laser Light On Water Evaporation From The Surface Of Polyurethane Swabs Doped With Surfactant, Collin Campbell

Chemical Engineering Undergraduate Honors Theses

Polyurethane swabs are a common instrument for environmental sampling in the food, medical, and forensic fields due to their high recovery of organisms like viruses, spores, and bacteria. For sampling microbes in food and medical facilities, storage of the collected samples occurs under the absence of light to promote growth for more accurate testing. In the forensic fields, microbial growth results in sample contamination so the inhibition of this growth requires the drying of the swabs. This work studies the evaporation rates of water from polyurethane swabs under zero watt incident light, 30 W fluorescent bulb, 50 mW 532 nm …

Tactical Missile Performance For Single And Multi-Wire Embedded Propellant Configurations With Discontinuities, Paul B. Wilson

Theses and Dissertations

This research analyzes the performance of a nominal air-to-air tactical missile with varying configurations of wire-embedded end-burning solid propellant grains. Single and multi-wire models are developed to determine if total impulse and range is improved. Discontinuities in the wires are simulated to determine if gaps in the wire will affect overall performance. Five wire materials, seven wire diameters, and nine different break locations are tested. This research demonstrates wire discontinuities have negligible impact on performance and carbon nanotube fibers can theoretically improve total impulse by up to 25% compared to radially burning boost-phase grains while providing similar thrust outputs.

An Experimental And Numerical Investigation Of Flow Accelerated Flibe Corrosion, David B. Weitzel

Nuclear Engineering ETDs

Renewed interest in molten salt reactor technology has brought to light the need for a better understanding of FLiBe corrosion. To this end a flowing FLiBe corrosion test loop was designed to test the flow effects of FLiBe corrosion. The loop consists of a pump, melt tank, and stainless-steel tubing assembly that heats the molten salt to high temperatures and circulates it over test specimens. The experiment has been constructed and has completed initial shakedown testing.

To support the flowing FLiBe experiment, a numerical corrosion model that couples FLiBe electrochemistry, solid metal diffusion, and mass transport was implemented. The model …

Capillary Forces In Partially Saturated Thin Fibrous Media, Ali Moghadam

Theses and Dissertations

Capillarity is often exploited in self-cleaning, drag reducing and fluid absorption/storage (sanitary products) purposes just to name a few. Formulating the underlying physics of capillarity helps future design and development of optimized structures. This work reports on developing computational models to quantify the capillary pressure and capillary forces on the fibrous surfaces. To this end, the current study utilizes a novel mass-spring-damper approach to incorporate the mechanical properties of the fibers in generating virtual fibrous structures that can best represent fibrous membranes. Such virtual fibrous structures are then subjected to a pressure estimation model, developed for the first time in …

Design Process For The Containment And Manipulation Of Liquids In Microgravity, Chris Meek

Theses and Dissertations--Mechanical and Aerospace Engineering

In order to enhance accessibility to microgravity research, the design process for experiments on the ISS must be streamlined and accessible to all scientific disciplines, not just aerospace engineers. Thus, a general design and analysis toolbox with accompanying best practices manual for microgravity liquid containment is proposed. The work presented in this thesis improves the design process by introducing a modular liquid tank design which can be filled, drained, or act as a passive liquid-gas separation device. It can also be pressurized, and used for aerosol spray. This tank can be modified to meet the design requirements of various experimental …

Form Stable Phase-Change Materials, Russell Dent, Marjan Kashfipour, Nitin Mehra, Jiahua Zhu

Williams Honors College, Honors Research Projects

This work investigates the use of two different polyols, xylitol (Xyl) and erythritol (Ery), in conjunction with boron nitride (BN) aerogels, for the purpose of creating thermally conductive composites. While the BN filler in Xyl composites achieved a high anisotropic thermal conductivity of up to 4.53 W/m-K at 18.2 weight percent filler loading, they do not exhibit good phase-change material qualities due to a low solidification enthalpy even at low cooling rates. Alternatively, the BN-Ery composites have shown promising results with a solidification enthalpy of 225.14 J/g and a melting enthalpy of 385.84 J/g at a heat rate of 5 …

Approximate Analytical Solution For Mathematical Models Of Thermal Ignition And Non-Isothermal Catalytic Zero Order Reaction In A Spherical Geometry, Moustafa A. Soliman

Chemical Engineering

In this paper an approximate analytical solution for the Frank-Kamenetskii equation modeling thermal ignition without the depletion of the combustibles in a spherical annulus and non-isothermal zero order reaction in spherical catalyst particle is presented. The approximate solution is compared with the numerical solution and is in good agreement with the numerical solution. The approximate solution obtained is valid for all values of the distance parameter. Multiple solutions occur for some range of Frank-Kamenetskii parameter (λ). The multiplicity is infinite for the case of a solid sphere and λ=2.Interesting relation is obtained for λ at the turning points. For the …

Void Fraction Measurements In Large (0.3 M) Diameter Bubble Column Using Wire Mesh Sensor And Pressure Transducers- Effect Of Sparger, Afolabi Gabriel Ojo

Dissertations and Theses

The importance of the accurate temporal and spatial measurements of the two-phase flow parameters in bubble columns is very well known. The aim of this research work is to report the spatial measurements of the void fraction distribution in a 30 cm diameter cylindrical bubble column using Wire Mesh Sensor (WMS) tomography and Pressure Transducers. Pair of WMS sensors, with a 64×64 wire configuration of each sensor, were installed which are separated by a distance along the axis of the bubble column. Wire Mesh Sensors and PTs Data were collected for time-averaged and transient with a sampling frequency of 1000 …

Air Ingress And Heat-Driven Flow Relaminarization In A Very High Temperature Reactor (Vhtr), Apoorva Rudra

Dissertations and Theses

Very High Temperature Reactors (VHTRs) are one of six Generation IV reactors that have been proposed for DOE’s Next Generation Nuclear Plant. In addition to using gaseous coolants, VHTRs also display benefits of passive safety systems including intra-core natural circulation for heat removal in accident scenarios. However, a number of substantial engineering challenges are expected in VHTRs, and due to the high temperatures of the coolant involved, material behavior in various components needs to be better understood. Our work focuses mainly on two key phenomena that could lead to localized hot spots in the VHTR reactor core if not addressed …

Intensification Of Gas Absorption In A Downward Flow Microbubble Bioreactor, Manizheh Ansari

Dissertations and Theses

Bioreactors are of interest for value-upgrading of stranded or waste industrial gases, such as CO, CH₄, or syngas. Process economics requires reduction of reactor cost and size while maintaining high production rate via rapid delivery of gas feedstock to the liquid phase which in turn requires a high volumetric mass transfer rate (). One strategy to achieve this goal is to increase interfacial area density, a, to >3000 m² m^-3, while minimizing use of energy. Here we show a novel reactor column design that uses a micro-jet array to break feedstock at ambient pressure …

Gas Hold-Up Measurements In 0.3 M Diameter Bubble Column: Effect Of Electrolytes, Heber Blanco De Brand

Dissertations and Theses

The present work reports the axial, radial and temporal gas hold-up profiles in a 0.3 m diameter batch bubble column using a pair of Wire Mesh Sensors and six pressure transducers.

Synthesis, Functionalization, And Application Of Nanofiltration And Composite Membranes For Selective Separations, Andrew Steven Colburn

Theses and Dissertations--Chemical and Materials Engineering

Future nanofiltration (NF) membranes used for selective separations of ions and small organic molecules must maintain performance in environments where high concentrations of total dissolved solvents or foulants are present. These challenges can be addressed through the development of composite membranes, as well as the engineering of enhanced surface properties and operating conditions for existing commercial membranes.

In this work, ion transport through commercial thin film composite (TFC) polyamide NF membranes were studied in both lab-prepared salt solutions and industrial wastewater. The dependence of several variables on ion rejection was investigated, including ion radius, ion charge, ionic strength, and temperature. …

Synthesis, Characterization And Applications Of Reduced Graphene Oxide And Composite Membranes For Selective Separations And Removal Of Organic Contaminants, Ashish Aher

Theses and Dissertations--Chemical and Materials Engineering

Among the next generation materials being investigated for membrane development, partially reduced Graphene Oxide (rGO) has received increasing attention from the membrane community. rGO-based nanofiltration membranes have shown promising results in applications such as partial desalination, organic contaminant removal, gas-phase separations, and separations from solvent media. rGO offers a unique platform compared to common polymeric membranes since it can be used for separation applications in both aqueous and organic solvent media. An rGO-based platform could also be utilized to synthesize reactive membranes, giving rGO membranes the additional capability of reactively removing organic contaminants. This research focuses on the synthesis of …

Removal Of Carbamazepine From Drinking Water, Adam Johnson, Thomas Krumpolc, Jordan Gadberry, Juan Rodriguez, Paolo Marrero-Rivera, Zachary Wiese

Chemical Engineering Undergraduate Honors Theses

Due to the increasing prevalence of prescription medication over the past few

decades, pharmaceuticals have accumulated in various water sources. This has become a

public health concern because many pharmaceuticals have limited research on the effects

of chronic low-level exposure. According to the World’s Health Organization (WHO),

traces of pharmaceuticals products have been reported in different water sources such as

surface waters, wastewater, groundwater, and drinking water.[1] One pharmaceutical of

interest that has been detected in water sources is carbamazepine. Carbamazepine is a

common pharmaceutical prescribed for the treatment of seizure disorders, neuropathic

pain, and various psychological disorders. It’s mechanism …

Performance Evaluation And Solutions For Port Congestion Focused On The Container Terminal : A Case Study Of Khalifa Bin Salman Port (Kbsp) Kingdom Of Bahrain, Mohamed Ebrahim A.S. Alhameedi, Abud Jamal Said, Tri Wahyunita Mudjiono

World Maritime University Dissertations

No abstract provided.

Molecular Dynamics Studies On Nanoscale Confined Liquids, Alper Celebi

Mechanical Engineering Research Theses and Dissertations

Liquid transport in nanochannels have been attracting great interests, especially for last two decades, owing to its potential applicability in various fields including biochemistry, medical science and engineering. For exploring and generating new ideas in the field of nanofluidics, molecular simulation techniques have become an ideal way due to the experimental challenges impeding the field of nanofluidics in fabrication and measurements.

In this dissertation, we perform molecular dynamics simulations to investigate liquid transport behavior in nanoscale channels. The expanse of this dissertation concerns several fundamental topics in nanoscale liquid transport phenomena such as liquid properties in nanoscale confinements, interfacial flows …

Experimental And Numerical Investigation Of Liquid-Assisted Gas-Lift Unloading, Renato Peixoto Coutinho

LSU Doctoral Dissertations

The case for a unique form of gas-lift unloading, termed “Liquid-Assisted Gas-Lift (LAGL),” is presented. This work demonstrates that the injection of a gas-liquid mixture allows transport of gas to a deep injection point utilizing injection pressure considerably lower than single-phase gas injection. The LAGL is demonstrated in a 2,880 ft deep test well. The test well is kicked-off using an injection pressure that would normally be lower than the pressure for single-point single-phase gas injection at this depth. Experimental results indicate that the LAGL can lower the injection pressure by up to 75%.

This work breaks the LAGL system …

Chemotherapeutic Drug Cytotoxicity Measurement With A 3d Biomimetic Microfluidic Device And Computational Fluid Dynamics Model, Maryam Moarefian, Caroline Jones, Luke Achenie, Danesh Tafti

Biology and Medicine Through Mathematics Conference

No abstract provided.

Removal Of Carbamazepine From Drinking Water, Zachary Wiese

Chemical Engineering Undergraduate Honors Theses

Due to the increasing prevalence of prescription medication over the past few

decades, pharmaceuticals have accumulated in various water sources. This has become a

public health concern because many pharmaceuticals have limited research on the effects

of chronic low-level exposure. According to the World’s Health Organization (WHO),

traces of pharmaceuticals products have been reported in different water sources such as

surface waters, wastewater, groundwater, and drinking water.[1] One pharmaceutical of

interest that has been detected in water sources is carbamazepine. Carbamazepine is a

common pharmaceutical prescribed for the treatment of seizure disorders, neuropathic

pain, and various psychological disorders. It’s mechanism …

Polymer Nanocomposites Containing High Aspect Ratio Particulates: Innovation In Co-Extruded Multilayer Barrier Films, Kevin Meyers

Dissertations

Delaminated montmorillonite (MMT) clay/ maleic anhydride grafted LLDPE nanocomposite multilayer films with alternating layers of LDPE were produced through multilayer co-extrusion. The MMT concentration within the nanocomposite layers was increased through annealing the films in the melt due to a mismatch in interdiffusion rates of the polymer layers. Analysis of the nanocomposite layers upon annealing revealed that the platelets impinged upon one another resulting in significant improvement in oxygen barrier in the multilayer system, exceeding the results of bulk nanocomposites.

Model analysis demonstrated that increasing the nanoplatelet aspect ratio or initial concentration in the filled layers would lead to even …

Review Of Challenges And Advances In Modification Of Food Package Headspace Gases, Ziynet Boz, Bruce A. Welt, Jeffrey K. Brecht, William Pelletier, Eric Mclamore, Gregory A. Kiker, Jason E. Butler

Journal of Applied Packaging Research

Modified Atmosphere Packaging (MAP) has been widely used as an effective way to preserve foods. Fresh produce, meat and meat products, seafood, and dairy products can benefit from modified gaseous atmospheres, which are usually achieved by reducing oxygen and increasing carbon dioxide concentrations, within limits, defined by product tolerances. MAP of fresh produce is particularly challenging because products are living and respiring. Respiration rates depend on several factors including temperature, oxygen, and carbon dioxide concentrations. Balancing package permeation with respiration is challenging, often due to limited selection of practical packaging materials. Failing to remain within tolerance limits of products leads …

Mobility Of Nano-Particles In Rock Based Micro-Models, Jagannath Upadhyay

LSU Doctoral Dissertations

A confocal micro-particle image velocimetry (C-μPIV) technique along with associated post-processing algorithms is detailed for obtaining three dimensional distributions of nano-particle velocity and concentrations at select locations of the 2.5D (pseudo 3D) Poly(methyl methacrylate) (PMMA) and ceramic micro-model. The designed and fabricated 2.5D micro-model incorporates microchannel networks with 3D wall structures with one at observation wall which resembles fourteen morphological and flow parameters to those of fully 3D actual reservoir rock (Boise Sandstone) at resolutions of 5 and 10 μm in depth and 5 and 25 μm on plane. In addition, an in-situ, non-destructive method for measuring the geometry of …

Pore-Scale Analysis Of Interfacial Instabilities And Impact Of Heterogeneity On Relative Permeability By Lattice Boltzmann Method, Zhipeng Zhu

LSU Master's Theses

Interfacial instabilities occur often during immiscible fluid flow through porous media and their understanding is essential for waterflooding operations or other oil recovery processes. Although many studies including experimental and numerical have been done to reproduce and analyze the interfacial instabilities in porous median, there is still significant knowledge gap in fundamental understanding of these flow instabilities at the pore-scale. In order to better understand the interfacial instabilities phenomenon, the pore-scale simulations are performed. In this study, Lattice Boltzmann Method is used to simulate two different types of interfacial instabilities: viscous fingering and capillary fingering in irregular sphere packs by …

Heat, Charge And Spin Transport Of Thin Film Nanostructures, Devin John Wesenberg

Electronic Theses and Dissertations

Understanding of fundamental physics of transport properties in thin film nanostructures is crucial for application in spintronic, spin caloritronics and thermoelectric applications. Much of the difficulty in the understanding stems from the measurement itself. In this dissertation I present our thermal isolation platform that is primarily used for detection of thermally induced effects in a wide variety of materials. We can accurately and precisely produce in-plane thermal gradients in these membranes, allowing for thin film measurements on 2-D structures. First, we look at thermoelectric enhancements of doped semiconducting single-walled carbon nanotube thin films. We use the Wiedemann-Franz law to calculate …

Characterization Of Rotary Bell Atomizers Through Image Analysis Techniques, Jacob E. Wilson

Theses and Dissertations--Mechanical and Aerospace Engineering

Three methods were developed to better understand and characterize the near-field dynamic processes of rotary bell atomization. The methods were developed with the goal of possible integration into industry to identify equipment changes through changes in the primary atomization of the bell. The first technique utilized high-speed imaging to capture qualitative ligament breakup and, in combination with a developed image processing technique and PIV software, was able to gain statistical size and velocity information about both ligaments and droplets in the image data. A second technique, using an Nd:YAG laser with an optical filter, was used to capture size statistics …

Investigation On The Potential Of A Co2 Capture System, Downstream Of The Aftertreatment System For A Heavy-Duty Engine Application, Murchana Pathak

Dissertations, Master's Theses and Master's Reports

The transportation sector accounts for the second largest source of CO₂ emissions after power generation. New Corporate Average Fuel Economy (CAFE) regulations are focusing on improving energy through reduced fuel consumption and greenhouse gas emissions. This work investigates the potential of a CO₂ capture system downstream of an aftertreatment system for a heavy-duty engine application. Amine absorption has been described as one of the most effective ways to capture CO₂ from the exhaust for point sources. Therefore, using thermal-swing absorption process with potassium carbonate (K₂CO₃) as the absorbent liquid, a process was analyzed …

Developing A 3d In Vitro Model By Microfluidics, Hung-Ta Chien

Dissertations and Theses

In vitro tissue models play an important role in providing a platform that mimics the realistic tissue microenvironment for stimulating and characterizing the cellular behavior. In particular, the hydrogel-based 3D in vitro models allow the cells to grow and interact with their surroundings in all directions, thus better mimicking in vivo than their 2D counterparts. The objective of this thesis is to establish a 3D in vitro model that mimics the anatomical and functional complexity of the realistic cancer microenvironment for conveniently studying the transport coupling in porous tissue structures. We pack uniform-sized PEGDA-GelMA microgels in a microfluidic chip to …