Transport Phenomena Commons^™

Design And Analysis Of Marangoni-Driven Robotic Surfers, Mitchel L. Timm

Dissertations, Master's Theses and Master's Reports

We designed and experimentally studied the dynamics of two robotic systems that surf along the water-air interface. The robots were self-propelled by means of creating and maintaining a surface tension gradient resulting from an asymmetric release of isopropyl alcohol (IPA). The imbalance in the distribution of surface tension surrounding the robots generates a propulsive force commonly referred to as Marangoni propulsion. First, we considered a single surfer, which was custom-made with novel control mechanisms that allow for both forward motion and steering to be remotely adjusted solely through the manipulation of local surface stresses. We analyzed the performance of this …

Fundamentals Of Microgel Flooding And Nanoparticles-Stabilized Foams In Enhanced Oil Recovery, Shuaijun Li

Dissertations and Theses

For centuries oil has remained a critical energy source for human civilization. After years of extraction, many oil fields have reached or are reaching a decline stage of production, even though up to a half of the total crude oil reserves in these fields has not been recovered yet. One reason is due to the structural heterogeneity of the oil reservoirs—reservoirs may consist of regions of higher permeability with larger pore size and regions of lower permeability with smaller pore size. Displacing fluids tend to flow through large permeability zones only without reaching the oil trapped in low permeability region; …

Droplets In An Electric Field: Surface Rheology, Coalescence And Rebound, Yu Han

Dissertations and Theses

Electrocoalescence is the process in which pairs of conducting droplets suspended in a continuous dielectric (nonconducting) liquid phase are drawn together and merge upon the application of an electric field. The electric field polarizes each of the droplets in the field direction. The polarization causes the drops to deform and drives a dipolar attraction which forces them to approach each other and coalesce. Many technologies use electric fields to manipulate fluid dispersions. Electrocoalescence is an essential unit operation for separating water droplets in a crude oil. This water in oil emulsion is stabilized by surfactants, such as asphaltenes, resins and …

Design And Control Of Intensified Membrane Reactor Systems Through Module-Based Design Approach, Brent Bishop

Graduate Theses, Dissertations, and Problem Reports (ETD)

As interest in the modularization and intensification of chemical processes continues to grow, more research must be directed towards the modeling and analysis of intensified process units. Intensified process units such as membrane reactors pose unique challenges pertaining to design and operation that have not been fully addressed in the reported literature. This work aims to address the design and control challenges caused by the integration of phenomena and the loss of degrees of freedom (DOF) that occur in the intensification of modular membrane reactor units.

First, a novel first-principles approach for modeling membrane reactors is developed using the AVEVA …

Advanced Process Modeling And Optimization Of Amine-Based Carbon Capture Process, Paul Jide Terhemba Akula

Graduate Theses, Dissertations, and Problem Reports (ETD)

With the rise of carbondioxide (CO2) concentration in the atmosphere to more than 400 parts per million (ppm), research efforts have been focused on achieving net-zero carbon emission technologies. Post-combustion CO2 capture (PCC) is a key strategy in reducing CO2 emissions. Amine-based CO2 capture is the baseline technology for retrofitting existing power stations. However, the integration of amine-based PCC technology with power plants to reduce greenhouse gas emissions incurs a high energy penalty, decreasing a powerplant’s efficiency by about 23 percentage points. Understanding the capture plant dynamics plays an important role in its technical and economic performance. Rigorous models are …

Numerical Investigation On The Effect Of Spectral Radiative Heat Transfer Within An Ablative Material, Raghava S. C. Davuluri, Rui Fu, Kaveh A. Tagavi, Alexandre Martin

Mechanical Engineering Faculty Publications

The spectral radiative heat flux could impact the material response. In order to evaluate it, a coupling scheme between KATS - MR and P1 approximation model of radiation transfer equation (RTE) is constructed and used. A Band model is developed that divides the spectral domain into small bands of unequal widths. Two verification studies are conducted: one by comparing the simulation computed by the Band model with pure conduction results and the other by comparing with similar models of RTE. The comparative results from the verification studies indicate that the Band model is computationally efficient and can be used to …

Water Recovery From Bioreactor Mixed Liquors Using Forward Osmosis With Polyelectrolyte Draw Solutions, Calen Raulerson

All Theses

The objective of this research was to test the feasibility of using forward osmosis (FO) with polyelectrolyte draw solutions to recover water from bioreactor mixed liquors. When combined with an Anaerobic Osmotic Membrane Bioreactor (AnOMBR), such a system could process fecal and food waste from astronauts aboard the International Space Station (ISS) and reclaim important nutrients and water. This project focused on measuring the obtainable water recovery rates from bioreactor effluent, and the identifying challenges associated with the operation.

AnOMBRs feature several advantages over aerobic bioreactors, and non-osmotic anaerobic membrane bioreactors (AnMBR). Anaerobic bioreactors avoid the significant energy costs of …

Towards Long Term Colloid Suspension In A Vertically Rotated System., Md Mahmudur Rahman

Electronic Theses and Dissertations

Within a colloidal suspension gravity may compromise the observation of governing physical interactions, especially those that are weak and/or take significant time to develop. Conducting the experiment in a long-term microgravity environment is a viable option to negate gravitational effects, though significant resources are required to do so. While it may not be possible to simulate long-term microgravity terrestrially, particles can resist quick sedimentation in a confined suspension system rotating vertically with appropriate rotation speed. The goal of the investigation is to demonstrate the existence of long-term particle suspension regime for a certain colloidal suspension while characterizing colloidal behavior due …

Preliminary Development Of The Dialysis-Membrane-Based Passive Biocide Delivery System For Spacecraft Water Recovery Units, Rogelio Elias Garcia Fernandez

Graduate Theses and Dissertations

The purpose of this investigation is to explore the capabilities of a dialysis-membrane-based system for the in-line dosing of silver ions to treated water in spacecraft water recovery units. The spacecraft environmental control and life support system community (ECLSS) are interested in adopting silver ions as a biocide in future spacecraft water recovery processes since silver ions are effective biocide at concentrations that humans can safely consume. The system has been designed following the configuration of the Water Processor Assembly (WPA) aboard the International Space Station. In this configuration, silver ions have to be added at the last step in …

Cfd Simulations Of Macroscopic And Microscopic Multiphase Fluid Flow And Droplet Interaction, Aaron Harrington

LSU Master's Theses

Multiphase flow is a complex phenomenon which can be modeled on numerous different length scales, both macroscopically and microscopically. The use of a Euler-Euler model for Computation Fluid Dynamics (CFD) simulations of subcooled boiling phenomena is discussed in detail. The CFD conditions have been set up to mimic previous experimental conditions. A cylindrical vessel with subcooled liquid flow is heated along part of the axial wall of the vessel. A constant heat flux is applied to produce subcooled boiling. We discuss the development of the phase change within the vessel as well as the temperature profile, and validate the results …

Experimental Heat Transfer Investigations Of A Double Pipe U-Tube Heat Exchanger Equipped With Twisted Tape And Cut Twisted Tape Internals, Raj Kumar Nayak Maloth, Glen Cletus Dsouza, Swarna Mayee Patra

Mechanical and Materials Engineering Publications

For several decades, the use of heat exchangers for both heating and cooling applications has been established in industries ranging from process to space heating. Out of the various types of heat exchangers, U-tube heat exchangers are preferred owing to their abilities to handle larger flowrates and their simplicity in construction. U-tube exchangers are often equipped with innards of various forms which facilitate higher heat transfer rates and thermal efficiencies. Although higher heat transfer rates have been established with the addition of internals, there is a lack of coherence on the underlying complex physical phenomena such as heat transfer boundary …

Gum Arabic-Capped Silver Nanoparticles For Electrochemical Amplification Sensing Of Methylene Blue In River Water, Ziad Khalifa, Moustafa Zahran, Magdy Zahran, Magdi Abdelazzem

Chemical Engineering

Herein, a novel electrochemical amplification sensor is developed for detecting methylene blue (MB) us- ing gum Arabic-capped silver nanoparticles (AgNPs) for the first time. Gum Arabic-AgNPs were fabricated via a direct chemical reduction technique using silver nitrate as an AgNPs precursor and gum Arabic as a reducing and capping agent. They were characterized using ultraviolet-visible (UV–Vis) spectrophotom- etry, square wave voltammetry (SWV), and transmission electron microscopy (TEM). UV–Vis and SWV results show the characteristic absorption and electrochemical oxidation peaks of the AgNPs at 431 nm and 0.18 V, respectively. Additionally, TEM images of the AgNPs show that they are spherical …

Fully Coupled Internal Radiative Heat Transfer For The 3d Material Response Of Heat Shield, Raghava S. C. Davuluri, Rui Fu, Kaveh A. Tagavi, Alexandre Martin

Mechanical Engineering Faculty Publications

The radiative transfer equation (RTE) is strongly coupled to the material response code KATS. A P-1 approximation model of RTE is used to account for radiation heat transfer within the material. First, the verification of the RTE model is performed by comparing the numerical and analytical solutions. Next, the coupling scheme is validated by comparing the temperature profiles of pure conduction and conduction coupled with radiative emission. The validation study is conducted on Marschall et al. cases (radiant heating, arc-jet heating, and space shuttle entry), 3D Block, 2D IsoQ sample, and Stardust Return Capsule. The validation results agree well for …

Exploration Of The Sludge Biodiesel Pathway, Zachary Christman

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Wastewater sludge is an overlooked source of fat, oil, and grease (FOG) that could be converted into biodiesel. The United States produces about 8 million tons of sludge per year. The disposal cost for this amount of sludge is about 2 billion US dollars. The widespread availability and low cost of sludge compared to other biodiesel raw materials make it an economical choice for a renewable fuel. Using sludge as a raw material can produce 25 to 30 mg per gram of fatty acid methyl ester (FAME); the main component of biodiesel. Sludge biodiesel has the potential of transforming a …

Analysis Of Fluid Flow In Redox Flow Batteries, Erfan Asadipour

McKelvey School of Engineering Graduate Student Theses & Dissertations

Redox flow batteries (RFB) hold great potential for large-scale stationary energy storage. However, their low energy density compared to other energy storage systems must improve for feasibility. Electrolyte flow distribution affects current density distribution and providing a uniform current density distribution is one way to improve RFB performance. Additionally, reducing the power consumption of the electrolytes’ pump as a source of energy loss in RFB systems increases their efficiency. Investigating both subjects requires analysis of the fluid dynamics in RFB cells.

In this thesis, a novel, computationally cost-effective hydraulic-electrical analogous model (HEAM) was developed to study fluid dynamics by implementing …

Image Analysis Of Charged Bimodal Colloidal Systems In Microgravity., Adam J. Cecil

Electronic Theses and Dissertations

Colloids are suspensions of two or more phases and have been topics of research for advanced, tunable materials for decades. Stabilization of colloids is typically attributed to thermodynamic mechanisms; however, recent studies have identified transport or entropic mechanisms that can potentially stabilize a thermodynamically unstable colloidal system. In this study, suspensions of silsesquioxane microparticles and zirconia nanoparticles were dispersed in a nitric acid solution and allowed to aggregate for 8-12 days in microgravity aboard the International Space Station. The suspensions were subsequently imaged periodically at 2.5x magnification. Due to the inadequacy of existing image analysis programs, the python package “Colloidspy” …

Graphical Design And Analysis Of Mass Exchange Networks Using Composition Driving Forces, Nessren Mohamed Farrag, Dina Ahmed Kamel, Ayat Ossama Ghallab, Mamdouh Ayad Gadalla, Mai Kamal Fouad

Chemical Engineering

Pinch analysis is a methodology for minimizing energy and mass consumption in different industries. It has been widely applied for more efficient processes. This study presents a new graphical-approach to analyze and design Mass Integration (MI) and exchange networks that follows Pinch principles to guarantee maximum mass recovery with minimum losses. This technique uses the composition driving forces in network representation as it rules the mass transfer between streams. The proposed approach can be applied on both existing mass networks as well as new ones. This graphical representation a visual descriptive design tool to describe and explain the details of …

Prediction Of Self-Diffusion Constants In Model And Real Systems Using Machine Learning, Joshua P. Allers

Chemical and Biological Engineering ETDs

Understanding diffusion of chemical compounds is important for the design and optimization of many chemical engineering and energy processes. Recent modifications to the Darken equation allow for accurate prediction of Maxwell-Stefan (MS) diffusion in mixtures. Still, there are few practical applications due to the requirement of individual self-diffusion constants. A reliable predictive model for self-diffusion constants would be highly valuable when used in conjunction with the modified Darken equation. Here, we show that Machine Learning (ML) can be used to develop generalized models for self-diffusion in Lennard Jones (LJ) systems and real systems of pure solutions. The use of Artificial …

Data-Driven Tools Guided By First-Principles For Scale Modeling, Sadegh Poozesh

Progress in Scale Modeling, an International Journal

For decades, traditional scale-modeling techniques have been relying on first-principles models (FPMs). FPMs have been used to find non-dimensional numbers (PIs) and identify normalized underlying forces and energies behind the phenomenon in focus. The two main challenges with FPM-based PIs extraction are finding the relevant PIs and proper correlations between PIs. The emergence and surge of data-driven modeling (DDM) provide a new opportunity to leverage experimental data in model development across scales/plants. In this paper, first, the two mentioned issues in PIs development will be elaborated to reveal the gap, and second, a new insight into scale modeling and similarity …

Molecular To Macroscopic Understanding Of Chloroaluminate Anion Intercalation In Rechargeable Aluminum-Graphite Batteries, Jeffrey Xu

Dissertations and Theses

Today’s global energy challenges pose an urgent need to electrify transportation and better store intermittent renewable energy sources (e.g., solar and wind energy). For such large-scale battery applications, aluminum batteries are a promising “beyond lithium-ion” technology due to the high volumetric capacity, earth abundance, low-cost, and inherent safety of aluminum metal. However, there are very few compatible positive electrode materials that exhibit high energy density and cycling stability, in part due to the challenges of electrochemically intercalating highly charged Al³⁺ cations. Recently, graphite has been demonstrated as a promising positive electrode material in non-aqueous rechargeable aluminum batteries, which store …