Mechanical Engineering Commons^™

Bio-Inspired Wings In High Freestream Turbulence: A Numerical And Experimental Study, Alexia Martinez Ibarra

Theses and Dissertations

The aerodynamics and flow field characteristics of a NACA 0010 airfoil with leading-edge modifications were investigated in flow with freestream turbulence intensity of 4%. A set of 4 airfoils, each of them with different wavelength (4, 8, 10, 12 tubercles along the spanwise direction) was experimentally studied. An unmodified NACA 0010 airfoil was used as baseline. The Reynolds number was varied from 201,200 to 351,600. The angle of attack was varied within the range of -6 to 20 degrees. Several techniques were used to investigate the characteristics of the airfoils such as wake profile surveys, 6-axis force measurements, and Particle …

Mechanical Properties And Microstructure Evolution Of Ti2alc Under Compression In 25–1100 °C Temperature Range, Rogelio Benitez, W. H. Kan, H. Gao, M. O'Neal, G. Proust, A. Srivastava, Miladin Radovic

Mechanical Engineering Faculty Publications

This study investigates the effects of the initial grain size and temperature (ranging from room temperature to 1100 °C) on the mechanical properties and microstructure evolution of Ti2AlC MAX phase. A Hall-Petch like relationship is observed between compressive strength and the grain size below brittle-to-plastic transition temperature (BPTT). However, the compressive strength of fine-grained MAX phase decreases more rapidly with increasing temperature resulting in inverse Hall-Petch effect above BPTT. Results from postmortem EBSD analysis reveal complex microstructural evolution in both fine- and coarse-grained microstructures during loading at different temperatures. The pronounced drop in compressive strength for fine-grained microstructures at temperatures …

The Use Of Succinonitrile As An Electrolyte Additive For Composite-Fiber Membranes In Lithium-Ion Batteries, Jahaziel Villarreal, Roberto Orrostieta Chavez, Sujay A. Chopade, Timothy P. Lodge, Mataz Alcoutlabi

Mechanical Engineering Faculty Publications

In the present work, the effect of temperature and additives on the ionic conductivity of mixed organic/ionic liquid electrolytes (MOILEs) was investigated by conducting galvanostatic charge/discharge and ionic conductivity experiments. The mixed electrolyte is based on the ionic liquid (IL) (EMI/TFSI/LiTFSI) and organic solvents EC/DMC (1:1 v/v). The effect of electrolyte type on the electrochemical performance of a LiCoO₂ cathode and a SnO₂/C composite anode in lithium anode (or cathode) half-cells was also investigated. The results demonstrated that the addition of 5 wt.% succinonitrile (SN) resulted in enhanced ionic conductivity of a 60% EMI-TFSI 40% EC/DMC MOILE …

Tribological And Thermal Transport Of Ag-Vegetable Nanofluids Prepared By Laser Ablation, Jaime Taha-Tijerina, Sadasivan Shaji, Sreed Sharma Kanakkillam, Maria Isabel Mendivil Palma, Karla Aviña

Informatics and Engineering Systems Faculty Publications

Lubricants and fluids are critical for metal-mechanic manufacturing operations as they reduce the friction and wear of tooling and components, and serve as coolants to dissipate the heat generated in these operations. The proper application of these materials improves machine operative life and tooling, and decreases cost, energy, and time consumption for maintenance, damage, repairs, or the need to exchange pieces/components within the machinery. Natural or vegetable-based lubricants have emerged as a substitute for mineral oils, which harm the environment due to their low biodegradability and have negative effects on human health (e.g., causing skin/respiratory diseases). Thus, finding biocompatible and …

Hybrid Phase-Change Lattice Boltzmann Simulation Of Vapor Condensation On Vertical Subcooled Walls, Wandong Zhao, Yuan Gao, Ruijie Li, Songgang Qiu, Yin Zhang, Ben Xu

Mechanical Engineering Faculty Publications

Saturated vapor condensation on homogenous and heterogeneous subcooled walls is presented in this study by adopting a hybrid phase-change multiple-relaxation-time Lattice Boltzmann model. The effects of wall wettability on the condensation process, including droplets’ growth, coalescence and falling, and the influence of vapor flow to condensation are investigated. The results demonstrate that the heat fluxes around the triple-phase contact lines are higher than that in other cold areas in homogeneous subcooled walls, which actually indicates the fact that filmwise condensation is preventing the continuous condensation process. Furthermore, the dropwise condensation can be formed more easily on the heterogeneous surface with …

On The Spreading Of Non-Canonical Thermals From Direct Numerical Simulations, Kai Liu, ‪Nadim Zgheib, S. Balachandar

Mechanical Engineering Faculty Publications

We present results from direct numerical simulations on laminar and turbulent non-canonical thermals with an initial rectangular density distribution at a Reynolds number of Re = 500 and Re = 5000, respectively. We find the non-canonical shape to induce strong azimuthal variations in the thermal for both the laminar and turbulent cases. These include noticeable differences in downward and horizontal propagation speeds as well as differences in the strength of the vortex tube. These differences persist over a significant period of time and help generate a cross-flow component that is otherwise not present in canonical cases. The cross-flow component is …

Experimental Study On Plugging Behavior Of Degradable Fibers And Particulates Within Acid-Etched Fracture, Lufeng Zhang, Fujian Zhou, Wei Feng, Maysam Pournik, Zhun Li, Xiuhui Li

Mechanical Engineering Faculty Publications

As proven from field practices in North America and Northwest China, temporary plugging and diverting acid fracturing is an indispensable technology to enhance stimulation effect and hydrocarbon production of complex carbonate reservoirs. It's well-known that the key to the success of this technology lies in creating a temporary plugging within the previously created fractures. Consequently, many scholars have conducted laboratory experiments to investigate the plugging behavior of fibers and particulates. However, the current devices nearly have certain limitations in simulating temporary plugging experiments. Aiming at this problem, this paper introduced the fracture temporary plugging evaluation system with large fracture size, …

The Performance Of Sio2 And Tio2 Nanoparticles As Lubricant Additives In Sunflower Oil, Vicente Cortes, Karen Sanchez, Mataz Alcoutlabi, Javier A. Ortega

Mechanical Engineering Faculty Publications

In recent years, there has been growing concern regarding the use of petroleum-based lubricants. This concern has generated interest in readily biodegradable fluids such as vegetable oils. The present work evaluated the rheological and tribological characteristics of sunflower oil modified with silicon dioxide (SiO2) and titanium dioxide (TiO2) nanoparticles as lubricant additives at different concentrations. A parallel plate rheometer was used to evaluate the effects of concentration and shear rate on the shear viscosity, and the experimental data was compared with conventional models. The wear protection and friction characteristics of the oil-formulations were evaluated by conducting block-on-ring sliding tests. Surface …

Spectroscopic Investigations On Pvdf-Fe2o3 Nanocomposites, Dorina M. Chipara, Victor Kuncser, Karen Lozano, Mataz Alcoutlabi, Elamin Ibrahim, Mircea Chipara

Mechanical Engineering Faculty Publications

Polyvinylidene fluoride-iron oxide (PVDF-Fe2O3) nanocomposites have been obtained my melt mixing of PVDF with Fe2O3 nanoparticles. The interactions between the polymeric matrix and the nanofiller have been investigated by wide angle X-ray scattering (WAXS), Fourier transform infrared spectroscopy (FTIR), and Raman spectroscopy, using both red and green excitations (lasers). WAXS, FTIR, and Raman spectra confirm that all samples contain α PVDF as the major crystalline form of the polymeric matrix. Experimental data revealed small changes in the positions of X-ray lines as well as modifications of the width of X-ray lines upon loading by Fe2O3 nanoparticles. FTIR and Raman spectra …

Effects Of Chemically Assisted Magnetic Abrasive Finishing Process Parameters On Material Removal Of Inconel 625 Tubes, Gurpreet Singh, Harish Kumar, Harmesh Kumar Kansal, Anil K. Srivastava

Manufacturing & Industrial Engineering Faculty Publications

With technological developments in manufacturing fields, many advanced materials and alloys have been introduced to fulfill industrial requirements. One of such type of advanced materials, Inconel 625 possesses superior materialistic properties and finds number of industrial applications in Aerospace, Marine, Petro-chemical and Solar power stations etc. However, machining and finishing of Inconel 625 components are still remain difficult tasks to deals with. A recently developed finishing process: Magnetic Abrasive Finishing (MAF) process has been experimented to finish Inconel 625 surfaces but this process is not much effective to finish and machine Inconel 625 work surfaces. In present work, Chemically assisted …

A Hybrid Physical Model Based Artificial Neural Network Approach To Predict Surface Texture In The Honing Of Engine Cylinder Bore, Burhan Afzel, Xueping Zhang, Anil K. Srivastava

Manufacturing & Industrial Engineering Faculty Publications

This study proposes a hybrid model that utilizes a physical model and Artificial Neural Networks (ANN) approach to predict surface roughness during cylinder bore honing with an improved prediction efficiency of 90% compared to the standalone physical model. As a critical component of internal combustion engine technology, improvement in the surface roughness of cylinder bore can significantly reduce friction, wear and oil consumption, resulting in improved engine performance. Desired surface roughness in cylinder bore is imparted by honing, which serves as the terminal process in cylinder bore manufacturing. The cylinder bore honing process consists of rough honing, fine honing, and …

Experimental Study Of Condensation In A Thermoacoustic Cooler With Various 3d Printed Regenerators Using Water Vapor As The Working Fluid, Aibek Bekkulov, Andrew Luthen, Ben Xu

Mechanical Engineering Faculty Publications

Thermoacoustics (TA) deals with the conversion of heat into sound and vice versa. The device that transfers energy from a low temperature reservoir to a high temperature one by utilizing acoustic work is called TA cooler (TAC). The main components of a typical TAC are a resonator, a porous regenerator (e.g. stack of parallel plates) and two heat exchangers. The thermoacoustic phenomenon takes place in the regenerator where a nonzero temperature gradient is imposed, and interacts with the sound wave. The low temperature at the cold end of TAC can be used to condense water from the humid air and …

Synergistic Effect Of Nanocoatings For Corrosion And Wear Protection Of Steel Surfaces, Jaime Taha-Tijerina, Laura Peña Parás, Antonio Sánchez Fernández, Demófilo Maldonado Cortés, Pablo Sarmiento Barbosa, Jesús Rolando Adán López

Informatics and Engineering Systems Faculty Publications

The purpose of this paper is to evaluate the corrosion and wear protection of a steel substrate by epoxy vinyl ester nanocomposite coatings with Zn and TiO2 nanoparticle fillers. Steel substrates were coated with epoxy vinyl ester nanocomposites, varying Zn and TiO2 nanofiller concentrations and combinations of both nanoparticles. Corrosion resistance was evaluated by salt spray fog test during 480 h, according to ASTM B-117. The degree of damage was obtained quantitatively by measuring the enhancement in corroded area compared to the scribe mark. Tribological evaluation was performed with a ball-on-disk tribotester, according to ASTM G-99. Results showed that the …

Evaluation Of The Most Significant Factors Influencing The Production Rates Of Highway Construction Activities, Angelica M. Neira

Theses and Dissertations

The utilization of realistic production rates is key for the accurate estimation of the contract time in highway projects. Several factors have an impact on production rates and change the total duration of construction projects. To organize and complete projects in a timely, quality and financially responsible manner, projects need to be scheduled carefully. Schedulers and planners of the Texas Department of Transportation (TxDOT) have been noticing that the estimated timelines are far from the reality and want to investigate if external factors can be the cause of this discrepancy. Some of the factors considered in this study are the …

An Advanced Approach For Contract Time Determination In Highway Projects, Cuauhtemoc Torres Cantu

Theses and Dissertations

In project management, finishing a project on schedule is one of the most important aspects. The Texas Department of Transportation (TxDOT) has been experiencing delays in some projects that can be accounted to an inaccurate project time estimation process. This research presents the development of a user-friendly and comprehensive computer-based contract time determination system. The enhanced system implements probabilistic scheduling techniques such as Program Evaluation and Review Technique, and Monte Carlo Simulation. Additionally, the application of a lognormal two-point PERT method is explored in this study. The new system proposes the use of a database of production rates based on …

Application Of Solar Water Heaters For Industrial Use, Lucas T. Atkins

Theses and Dissertations

Solar water heating is a technology that is mainly used for domestic water heating in residential homes. In most applications, the idea is to make a home “off the grid” in that there is no requirement for outside infrastructure or need for energy utility to provide power to this home. This falls in line with the trend of “going green” in an effort to reduce energy use, increase efficiency, or reduce emissions and other harmful byproducts.

This technology can be adapted to reduce the energy costs of industrial manufacturing plants. By eliminating the need for certain sections of a process …

Graphene-Fibers Hybrid Structures As Adsorbents For Heavy Metal Ions In Aqueous Solutions, Dulce C. Capitanachi

Theses and Dissertations

The project focuses on the study of graphene-fiber hybrid structures for adsorption of heavy metal ions in aqueous solutions. Polyvinyl alcohol-based graphene–fiber structures were created using centrifugal spinning and a carbonization process.

Characterization methods of the graphene–fiber hybrid structures (GFHS) include SEM, FTIR, TGA, and EDX. Single-step batch-type adsorption studies were performed to analyze the interaction of Cu (II) and Pb (II) ions onto GFHS surface. Different heavy metal ion concentrations were used, as well as a variation of pH values. Elemental analysis of the adsorbent’s surface after filtration experiments was studied by EDX and spectroscopy to verify the presence …

Design And Testing Of A Modular Laser System With Laser Machining And Bioprinting Capabilities, Jesus Gonzalez

Theses and Dissertations

This thesis introduces the applications of ultrafast lasers while focusing on their bioprinting capabilities. A custom system was designed to utilize a femtosecond laser for 2D and 3D applications. The characteristics of lasers allow them to be efficiently used in machining, 3D printing, research, and more. Their power and precision allow them to be used for delicate work such as bioprinting. Bioprinting is a field holding great potential to benefit society. Studies conducted over the years prove its usefulness in printing cells and biomaterials, while showing there is still much to improve upon before being able to print fully functioning …

Investigation Into The Thermodynamics And Kinetics Of The Binding Of Cu2+ And Pb2+ To Tis2 Nanoparticles Synthesized Using A Solvothermal Process, Jesus Cantu, John Valle, Kenneth Flores, Diego Gonzalez, Carolina Valdes, Jorge Lopez, Victoria Padilla, Mataz Alcoutlabi, Jason Parsons

Mechanical Engineering Faculty Publications

In the present study, titanium (IV) sulfide (TiS2) was synthesized and investigated for the removal of Cu2+ and Pb2+ ions from aqueous solutions. TiS2 nanoparticles synthesized through a solvothermal synthesis were characterized using x-ray diffraction (XRD) and scanning electron microscopy (SEM). The average particle size for the TiS2 material was determined to be 8.03 ± 0.98 nm from the diffraction pattern. Studies were performed to examine the effects of pH, temperature, time, and interfering ions on the binding of Cu2+ and Pb2+ to the TiS2. As well isotherm studies were performed to determine the binding capacity of TiS2 for both …

Energy And Exergy Analysis Of A Novel Multiple-Effect Vapor Chamber Distillation System For High-Salinity Wastewater Treatment, Hamidreza Shabgard, Ramkumar Parthasarathy, Ben Xu

Mechanical Engineering Faculty Publications

A novel modular thermally-driven multiple-effect vapor chamber distillation (MVCD) system is presented for compact and portable desalination applications. The MVCD system consists of several vapor chambers connected in series with the condenser section of the upstream vapor chambers serving as the evaporator section of the following effect. A heat transfer model accounting for the major thermal resistances was developed to predict the heat transfer and distilled water production rates. A mass transfer analysis was performed to evaluate the effect of the accumulation of the non-condensable gasses within the chambers. An exergy analysis was also conducted to quantify the efficiency of …

Novel Silica Filled Deep Eutectic Solvent Based Nanofluids For Energy Transportation, Changhui Liu, Hui Fang, Xinjian Liu, Ben Xu, Zhonghao Rao

Mechanical Engineering Faculty Publications

Liquid range of nanofluids is a crucial parameter as it intensively determines their application temperature scope. Meanwhile, improved thermal conductivity and stability are of great significances and comprise the main fundamental research topics of nanofluids. In this work, 2-butoxy-3,4-dihydropyran (DP), produced from a convenient one-pot three-component reaction in water, was employed as dual lipophilic brusher and metal nanoparticle anchor. It was found that DP was able to enhance the dispersing ability and thermal conductivity of SiO2 nanoparticle filled deep eutectic solvent (DES) based nanofluids simultaneously. The key to the success of this protocol mainly relies on the electrophilic property and …

Sub-Optimal Tracking In Switched Systems With Controlled Subsystems And Fixed-Mode Sequence Using Approximate Dynamic Programming, Tohid Sardarmehni, Xingyong Song

Mechanical Engineering Faculty Publications

Optimal tracking in switched systems with controlled subsystem and Discrete-time (DT) dynamics is investigated. A feedback control policy is generated such that a) the system tracks the desired reference signal, and b) the optimal switching time instants are sought. For finding the optimal solution, approximate dynamic programming is used. Simulation results are provided to illustrate the effectiveness of the solution.

Pressure Effect On An Ocean-Based Humidification-Dehumidification Desalination Process, Yingchen Yang

Mechanical Engineering Faculty Publications

A new humidification-dehumidification (HDH) desalination process is proposed and analyzed. Being ocean based, the process does not produce any brine. It is largely powered jointly by solar energy, wind energy, and various types of ocean energies in a nearly natural way. A vacuum pump is employed to drive the air circulation throughout the HDH process. It is the only unit that consumes electricity. The HDH process is analyzed under various conditions, including using a low pressure (as low as to 0.2 atm) for humidification and the ambient pressure for dehumidification, running the entire HDH process around a low pressure (as …

Performance Evaluation Of Ce3+ Doped Flexible Pvdf Fibers For Efficient Optical Pressure Sensors, Carlos Hernandez, Santosh K. Gupta, Jose P. Zuniga, Jorge Vidal, Rene Galvan, Misael E. Martinez, Hector Guzman, Lilian N. Chavez, Yuanbing Mao, Karen Lozano

Mechanical Engineering Faculty Publications

Highlights

• Centrifugally spun cerium doped nonwoven fibrous mat are explored as a non-contact optical pressure sensor.

• The developed sensor depicted wide linear dynamic range and good pressure sensitivity.

• The sensor properties are based on the spectral shift, broadening and intensity enhancement.

• β-phase in doped fibers increases when compared to undoped PVDF.

• Cerium nitrate doped fiber exhibits a high-pressure sensitivity (dλ/dP ≈ 0.28 nm/GPa) with no luminescence quenching.

Abstract

This work proposes a highly novel centrifugally spun lanthanide doped nonwoven fibrous mat as a non-contact optical pressure sensor with a wide linear dynamic range and good pressure sensitivity. The sensor …

Forcespun Polydiacetylene Nanofibers As Colorimetric Sensor For Food Spoilage Detection, Marisol Valdez, Santosh K. Gupta, Karen Lozano, Yuanbing Mao

Mechanical Engineering Faculty Publications

Highlights

• PDA nanofiber mats are fabricated by Forcespinning® technique.

• The PDA nanofibers can monitor and assess meat deterioration and freshness.

• The PDA nanofibers possess fast response, excellent sensitivity and long shelf life.

• PDA nanofibers made from ECDA monomer have superior performance.

Abstract

Due to health and economic concerns, increasing attention has been attracted to the safety and quality control of food, particularly meat and seafood. Ammonia and biogenic amines (BAs), such as trimethylamine, putrescine and cadaverine, are released during the decomposition of meat protein. Therefore, the sensitive detection of the released BAs is crucial to the assessment of the safety …

Centrifugally Spun Α-Fe2o3/Tio2/Carbon Composite Fibers As Anode Materials For Lithium-Ion Batteries, Luis Zuniga, Gabriel Gonzalez, Roberto Orrostieta Chavez, Jason C. Myers, Timothy P. Lodge, Mataz Alcoutlabi

Mechanical Engineering Faculty Publications

We report results on the electrochemical performance of flexible and binder-free α-Fe₂O₃/TiO₂/carbon composite fiber anodes for lithium-ion batteries (LIBs). The composite fibers were produced via centrifugal spinning and subsequent thermal processing. The fibers were prepared from a precursor solution containing PVP/iron (III) acetylacetonate/titanium (IV) butoxide/ethanol/acetic acid followed by oxidation at 200 °C in air and then carbonization at 550 °C under flowing argon. The morphology and structure of the composite fibers were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), …

Synthesis Of Multiwall Α-Fe2o3 Hollow Fibers Via A Centrifugal Spinning Technique, Mandana Akia, K. A. Mkhoyan, Karen Lozano

Mechanical Engineering Faculty Publications

Highlights

• Hollow hematite (α-Fe2O3) fine fibers were fabricated via a simple, flexible, and scalable technique.

• An aqueous solution with iron precursor/polymer was used in the centrifugal spinning process

• Developed fibers show average wall thickness of 55 ± 15 nm and outer fiber diameter of 852 ± 86 nm

Abstract

Hollow hematite (α-Fe2O3) fine fibers with multiwall structure were synthesized by utilizing a centrifugal spinning technique. Aqueous solutions of polyvinyl pyrrolidone and iron (III) nitrate nonahydrate were prepared and spun into fibers. The precursor fibers were heat treated at 650 °C to form iron oxide fibers. Scanning electron micrographs revealed the …

Evaluating The Rheological And Tribological Behaviors Of Coconut Oil Modified With Nanoparticles As Lubricant Additives, Vicente Cortes, Javier A. Ortega

Mechanical Engineering Faculty Publications

In metal-forming processes, the use of lubricants for providing desirable tribological conditions at the tool–workpiece interface is critical to increase the material formability and prolonging tool life. Nowadays, the depletion of crude oil reserves in the world and the global concern in protecting the environment from contamination have renewed interest in developing environmentally-friendly lubricants derived from alternative sources such as vegetable oils. In the present study, the rheological and tribological behavior of coconut oil modified with nanoparticle additives was experimentally evaluated. Two different nanoparticle additives were investigated: Silicon dioxide (SiO₂) and copper oxide (CuO). For the two conditions, …

Tribological And Thermal Transport Performance Of Sio2-Based Natural Lubricants, Jaime Taha-Tijerina, Karla Aviña, Jose Manual Diabb

Informatics and Engineering Systems Faculty Publications

Fluids and lubricants are critical for the mechanical manufacturing processing of metals, due to a high amount of friction generated, also reflected as heat, could wear and damage tooling and machine components. The proper application of lubricants increases machinery lifetime, decreases long-term costs, and energy and time consumption due to the maintenance or components exchange/repairs. Besides being non-renewable, mineral oils bring consequences to the environment due to their low biodegradability and could affect the user with respiratory and skin diseases. Recently, due to an increase in environmental awareness, the search of biocompatible and efficient lubricants has become a technology goal. …

Design And Validation Of A Modular Instrument To Measure Torque And Energy Consumption In Industrial Operations, Mary De La Cruz, Ramiro Gonzalez, Jesus A. Gomez, Atilano Mendoza, Javier A. Ortega

Mechanical Engineering Faculty Publications

A modular torque measuring instrument capable of performing tapping torque tests (TTT) according to the ASTM D-5619 standard was designed, developed, and validated. With this new instrument, the performance of different lubricants can be evaluated in terms of frictional torque and energy consumption during tapping processes. This instrument can adapt onto any conventional milling machine or CNC machine and operate under various machining operations such as tapping, drilling, and other processes. To validate the design and performance of this new device, three commercially available lubricants were evaluated. From the three tested conditions, the results showed good repeatability, with consistent results …