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Articles 421 - 450 of 657
Full-Text Articles in Mechanical Engineering
Raman Spectroscopy And Molecular Bases Of Elasticity: Sebs-Graphite Composites, Dorina M. Chipara, Denis M. Panaitescu, Karen Lozano, Raluca Augusta Gabor, Cristian Andi Nicolae, Mircea Chipara
Raman Spectroscopy And Molecular Bases Of Elasticity: Sebs-Graphite Composites, Dorina M. Chipara, Denis M. Panaitescu, Karen Lozano, Raluca Augusta Gabor, Cristian Andi Nicolae, Mircea Chipara
Mechanical Engineering Faculty Publications
For polymer-based (nano)composites, the strain/stress induced by reinforcing agents within the polymer may be identified and quantified at molecular level by Raman spectroscopy. The manuscript focuses on correlations between mechanical properties of composites and their Raman spectra, with emphasis on the displacements of the position(s) of Raman lines due to local strains/stress. Investigations on polystyrene-(ethylene-co-butylene)-styrene block copolymers filled with various amounts of graphite are reported. The modifications of Raman's parameters (line intensity, position, and width) upon the loading with graphite are analyzed. Raman revealed a strong dampening of molecular vibrations within the polymer, upon the loading with graphite, …
Electrostatically Actuated Double Wall Carbon Nanotubes To Include Intertube Van Der Waals Forces, Ezequiel Juarez Ocanas
Electrostatically Actuated Double Wall Carbon Nanotubes To Include Intertube Van Der Waals Forces, Ezequiel Juarez Ocanas
Theses and Dissertations
This work deals with the amplitude-frequency and amplitude-voltage responses of parametric and primary resonances of electrostatically actuated double-walled carbon nanotubes (DWCNTs). Nonlinear forces acting on the DWCNT are intertube van der Waals and electrostatic forces. Soft AC excitation and small viscous damping are assumed. In coaxial vibration, the outer and inner carbon nanotubes move together (in-phase), maintaining their geometric concentricity; while in noncoaxial vibration, the CNTs move in opposite direction (out-of-phase). Modal coordinate transformation is formulated. The Harmonic Balance Method (HBM) is used to find the free response solutions of the DWCNT. The Reduced Order Model (ROM) method is also …
Parametric Study Of Selective Laser Alloying Of Elemental Titanium And Boron Powders Using An Automated Deposition Mechanism, Julian V. Gonzalez
Parametric Study Of Selective Laser Alloying Of Elemental Titanium And Boron Powders Using An Automated Deposition Mechanism, Julian V. Gonzalez
Theses and Dissertations
An automatic powder deposition and leveling mechanism was designed and constructed to assist in surface roughness experiments for titanium-boron samples. Previously developed energy models and x-ray diffraction analysis was used to confirm the creation of titanium diboride samples. To study TiB2 at different energy values, a 52 (2 factors, 5 levels) factorial design was used and carried out under an argon atmosphere, through the AM250 laser melting system. Two experimental runs were carried out and a total of 50 samples were assigned a surface roughness measurement through the Dektak XT profilometer. Graphically and with statistical analysis, the data was determined …
A Study Of Human Balance And Coordination Using A Head Mounted Display, Daniel Gracia De Luna
A Study Of Human Balance And Coordination Using A Head Mounted Display, Daniel Gracia De Luna
Theses and Dissertations
Virtual Reality (VR) is growing with new technologies and applications. The new technologies help the user to feel more immersed in virtual environments, but interaction and immersion is an area that has not been well studied. Immersion is the feeling and reaction of users while they are in a virtual environment. This investigation is focused on the study of the human balance and coordination when human subjects are inside a virtual environment. Over 60 subjects are studied under an experiment, where their trajectory is captured and analyzed to identify possible differences or similitudes between male and female subjects.
An Experimental Study Of Thrust Augmentation With Asymmetrical Nozzle Driven Pulsed Ejector, Orlando Rodriguez
An Experimental Study Of Thrust Augmentation With Asymmetrical Nozzle Driven Pulsed Ejector, Orlando Rodriguez
Theses and Dissertations
With the emergence of V/STOL vehicles and unmanned aircrafts has come the resurgence of thrust augmentation through an ejector. The use of an ejector has many benefits such as being lightweight and simple design to manufacture. In this study a hot steady jet and a cold steady/unsteady jet was tested. The hot steady jet was produced by a JetCAT PX-180 rxi with a two-inch diameter nozzle exit. The hot steady jet was compared to the cold free steady and unsteady cases. The cold jet was tested under free steady and unsteady condition, as well as steady and unsteady ejector conditions. …
Assessment Of Some Of The Common Practices Used In Scheduling Highway Projects, Jennifer Reyes
Assessment Of Some Of The Common Practices Used In Scheduling Highway Projects, Jennifer Reyes
Theses and Dissertations
There are several factors documented in the literature that can affect the accuracy of estimated project durations in highway construction, such as weather, location, and soil conditions. Recently, the Texas Department of Transportation (TxDOT) raised a concern regarding some of the practices used when estimating the contract time for projects. This research presents an assessment of the effect that two practices identified have on the estimated project duration. These two practices include: 1) the estimated lead/lag times in project schedules and 2) scheduling with only critical or controlling activities. The effect of these practices is measured, primarily, by using four …
On The Role Of Sidewalls In The Transition From Straight To Sinuous Bedforms, Nadim Zgheib, S. Balachandar
On The Role Of Sidewalls In The Transition From Straight To Sinuous Bedforms, Nadim Zgheib, S. Balachandar
Mechanical Engineering Faculty Publications
We present results from direct numerical simulation on the transition from straight-crested to sinuous-crested bedforms. The numerical setup is representative of turbulent open channel flow over an erodible sediment bed at a shear Reynolds number of Reτ = 180. The immersed boundary method accounts for the presence of the bed. The simulations are two-way coupled such that the turbulent flow can erode and modify the bed, and in turn, the bed modifies the overlying flow. Coupling from the flow to the bed occurs through the Exner equation, while back coupling from the bed to the flow is achieved by …
Energy Harvesting Techniques To Power Onboard Railway Bearing Condition Monitoring Systems, Jacob Nathaniel Bensen
Energy Harvesting Techniques To Power Onboard Railway Bearing Condition Monitoring Systems, Jacob Nathaniel Bensen
Theses and Dissertations
Limitations of the standard wayside hotbox detection system as a method to identify failing railway bearings severely inhibit the reliability and safety of rail transport. An onboard bearing condition monitoring system would address and ameliorate the issues present in the current detection system. The onboard system would provide more frequent and reliable information regarding bearing condition. For the system to succeed in reducing maintenance time and preventing bearing failure, a method of providing the system with sufficient energy to power its instrumentation is necessary. The instrumentation location environment poses a significant challenge. The device must be placed on the steel …
Prognostics Models For Railroad Tapered Roller Bearings With Spall Defects On Inner Or Outer Rings, Constantine Tarawneh, Jennifer Lima, Nancy De Los Santos, Robert Jones
Prognostics Models For Railroad Tapered Roller Bearings With Spall Defects On Inner Or Outer Rings, Constantine Tarawneh, Jennifer Lima, Nancy De Los Santos, Robert Jones
Mechanical Engineering Faculty Publications
Rolling contact fatigue (RCF) is one of the major causes of failure in railroad bearings used in freight service. Subsurface inclusions resulting from impurities in the steel used to fabricate the bearings initiate subsurface fatigue cracks, which propagate upwards and cause spalling of the rolling surfaces. These spalls start small and propagate as continued operation induces additional crack formation and spalling. Studies have shown that the bearing temperature is not a good indicator of spall initiation. In many instances, the temperature of the bearing increases markedly only when the spall has spread across major portions of the raceway. In contrast, …
Multidirectional Pin-On-Disk Testing Device To Evaluate The Cross-Shear Effect On The Wear Of Biocompatible Materials, Vicente Cortes, Carlos A. Rodriguez Betancourth, Javier A. Ortega, Hasina Huq
Multidirectional Pin-On-Disk Testing Device To Evaluate The Cross-Shear Effect On The Wear Of Biocompatible Materials, Vicente Cortes, Carlos A. Rodriguez Betancourth, Javier A. Ortega, Hasina Huq
Mechanical Engineering Faculty Publications
One of the main causes of hip prostheses failure is the premature wear of their components. Multi-directional motion or “cross-shear” motion has been identified as one of the most significant factors affecting the wear rate of UHMWPE in total hip joint replacement prostheses. To better evaluate the effect of this cross-shear motion on the tribological behavior of different biomaterials, a new wear testing device has been designed and developed. This new instrument is capable to reproduce the “cross-shear” effect with bidirectional motion on bearing materials and to determine coefficient of friction (COF) between surfaces during testing. To validate the functionality …
Prototyping A Conductive Polymer Steering Pad For Rail Freight Service, Anthony A. Villarreal, Constantine Tarawneh, Miguel Ontiveros, James Aranda, Robert Jones
Prototyping A Conductive Polymer Steering Pad For Rail Freight Service, Anthony A. Villarreal, Constantine Tarawneh, Miguel Ontiveros, James Aranda, Robert Jones
Mechanical Engineering Faculty Publications
The AdapterPlus™ steering pad is a polymer component on a railcar that helps to reduce stresses on the axle as a railcar rounds a curve. One railway application requires a minimum of 240 mA to be passed through the steering pad to the rail, which activates air valves that control automated cargo gates. Currently, two copper studs are inserted into the pad to provide a conductive path. However, after continuous cyclic loading caused by normal service operation, the copper studs deform, wear, and eventually lose contact between the two surfaces rendering the pad nonconductive. One proposed solution to this problem …
Development Of Prognostics Techniques For Surface Defect Growth In Railroad Bearing Rolling Elements, Nancy De Los Santos
Development Of Prognostics Techniques For Surface Defect Growth In Railroad Bearing Rolling Elements, Nancy De Los Santos
Theses and Dissertations
One of the major causes of failure in railroad bearings used in freight service is rolling contact fatigue (RCF). RCF is due to subsurface inclusions which are a result from impurities in the steel that is used to fabricate the bearings. Once the bearings initiate subsurface fatigue cracks, they will then propagate upward and initiate spalling of the rolling surfaces. These spalls will begin small and continuously propagate with operation as this induces additional crack forming and spalling. Studies have indicated that bearing temperature is not a good indicator of spall initiation. In many cases, the temperature of the bearing …
Estimating The Outer Ring Defect Size And Remaining Service Life Of Freight Railcar Bearings Using Vibration Signatures, Joseph Montalvo, Constantine Tarawneh, Jennifer Lima, Jonas Cuanang, Nancy De Los Santos
Estimating The Outer Ring Defect Size And Remaining Service Life Of Freight Railcar Bearings Using Vibration Signatures, Joseph Montalvo, Constantine Tarawneh, Jennifer Lima, Jonas Cuanang, Nancy De Los Santos
Mechanical Engineering Faculty Publications
The railroad industry currently utilizes two wayside detection systems to monitor the health of freight railcar bearings in service: The Trackside Acoustic Detection System (TADS™) and the wayside Hot-Box Detector (HBD). TADS™ uses wayside microphones to detect and alert the conductor of high-risk defects. Many defective bearings may never be detected by TADS™ since a high-risk defect is a spall which spans more than 90% of a bearing’s raceway, and there are less than 20 systems in operation throughout the United States and Canada. Much like the TADS™, the HBD is a device that sits on the side of the …
Zinc Ferrite Based Gas Sensors: A Review, Kaidi Wu, Jianzhi Li, Chao Zhang
Zinc Ferrite Based Gas Sensors: A Review, Kaidi Wu, Jianzhi Li, Chao Zhang
Manufacturing & Industrial Engineering Faculty Publications
Flammable, explosive and toxic gases, such as hydrogen, hydrogen sulfide and volatile organic compounds vapor, are major threats to the ecological environment safety and human health. Among the available technologies, gas sensing is a vital component, and has been widely studied in literature for early detection and warning. As a metal oxide semiconductor, zinc ferrite (ZnFe2O4) represents a kind of promising gas sensing material with a spinel structure, which also shows a fine gas sensing performance to reducing gases. Due to its great potentials and widespread applications, this article is intended to provide a review on the latest development in …
Implementation Of Visual Supplements To Strengthen Pedagogical Practices And Enhance The Physical Understanding Of Fundamental Concepts In Engineering Mechanics, Eleazar Marquez, Samuel Garcia, Samuel Molina
Implementation Of Visual Supplements To Strengthen Pedagogical Practices And Enhance The Physical Understanding Of Fundamental Concepts In Engineering Mechanics, Eleazar Marquez, Samuel Garcia, Samuel Molina
Mechanical Engineering Faculty Publications
Mechanical Engineering is a discipline highly dependent on designing and implementing mechanical, thermal, or energy systems for the improvement of the human environment. Thus being a proficient Engineer involves having a strong mathematical background and a thorough physical understanding on how systems operate in order to apply analytical or numerical schemes during a design process. However, most of the students’ academic development is centered on deriving tedious equations and solving textbook problems, which are difficult to visualize and physically understand, and cloud their intuitive nature to comprehend a problem on its entirety. These conventional approaches and methods of disseminating content …
Creating A Learning Environment That Engages Engineering Students In The Classroom Via Communication Strategies, Eleazar Marquez, Samuel Garcia
Creating A Learning Environment That Engages Engineering Students In The Classroom Via Communication Strategies, Eleazar Marquez, Samuel Garcia
Mechanical Engineering Faculty Publications
In this research effort, the authors claim that possessing technical knowledge is not a sufficient asset to establish a learning environment that renders engagement with engineering students during lecture sessions, but rather the integration of various communication strategies that support students’ academic development. Research has noted that classroom context and conditions impact the degree of student learning and engagement and are further enhanced when students feel comfortable communicating with the instructor and with their peers. If such acquaintance is nonexistent, student participation may be stifled and limited despite the technical concerns arising during lecture sessions. Thus, it is imperative for …
Secondary Resonances Of Electrostatically Actuated Mems Cantilevers, Christopher I. Reyes
Secondary Resonances Of Electrostatically Actuated Mems Cantilevers, Christopher I. Reyes
Theses and Dissertations
In this work the behavior of micro-electromechanical (MEMS) cantilever resonators is investigated. The cantilever resonators are electrostatically actuated with hard AC voltage resulting in nine distinct resonances cases including super and subharmonic resonances. The amplitude frequency and amplitude voltage bifurcation diagrams are obtained for each of the nine resonance cases. Reduced order models (ROMs) are developed to include one and two modes of vibration. Three different methods are used to solve the ROMs namely 1) the method of multiple scales (MMS), which is a perturbation method used for one mode of vibration, 2) the homotopy analysis method (HAM), which is …
Design Of A Bedside Walker-Cane Hybrid To Aid Senior Adults Avoid Falls During Night Walks, Jorge L. Gutierrez
Design Of A Bedside Walker-Cane Hybrid To Aid Senior Adults Avoid Falls During Night Walks, Jorge L. Gutierrez
Theses and Dissertations
The objective of this research and development work is to design a device to help senior adults prevent fall during night walks indoors. The problem of elders falling at a night setting was found to be caused by the multiple environmental and medical conditions. The target demographic was found to be seniors from age 65 and older. Several occupational therapists and two physical therapists were consulted to gain knowledge on elders' behavior, possible improvements on current existing devices, and feedback regarding the early prototype built. Several products and patents were researched with a lack of findings on similar products that …
Biomechanics Of Lower Limb During The Golf Swing Using Opensim Modeling, Andrew B. Butler
Biomechanics Of Lower Limb During The Golf Swing Using Opensim Modeling, Andrew B. Butler
Theses and Dissertations
The purpose of this research is to investigate the biomechanics of the lower-limb using an inverse dynamics model. Experimental data, recorded by an integrated Motion Analysis – Force Plate System in the UTRGV Biomechanics Laboratory, is used to determine ground reaction forces and marker trajectories. OpenSim, a graphical musculoskeletal and computational platform, is used to model the body in three dimensions. The human body is modeled as a 12-segment linkage, consisting of 23 degrees-of-freedom and 92 muscles. The experimental data for the Biomechanics Laboratory is imported in OpenSim. Then, joint angles, generalized coordinates & accelerations of lower-limb segments, muscle forces, …
Experimental Study Of Condensation In Different 3d Printed Regenerators In A Thermoacoustic Cooler, Aibek Bekkulov
Experimental Study Of Condensation In Different 3d Printed Regenerators In A Thermoacoustic Cooler, Aibek Bekkulov
Theses and Dissertations
Thermoacoustics (TA) deals with the conversion of heat into sound and vice versa. Device that converts heat into acoustic work is called TA heat engine, while the device that transfers energy from a low temperature reservoir to a high temperature one by utilizing acoustic work is called TA cooler. A simple construction of TA cooler includes an acoustic speaker, a resonator tube and a regenerator stack in which the temperature gradient is being imposed. Such a TA cooler has several advantages over traditional compression/expansion cooling machine such as its simplicity of the construction, high reliability and lack of toxic refrigerants. …
Development Of Flexible Photo-Mechanoluminescent Polymeric Based Systems, Carlos Hernandez
Development Of Flexible Photo-Mechanoluminescent Polymeric Based Systems, Carlos Hernandez
Theses and Dissertations
The project focuses on the creation of nanofiber systems with enhanced photo-mechanoluminescent response and high mechanical flexibility to further enhance promising optical applications. Lanthanide-Polyvinyl Di-Fluoride fiber systems were created using centrifugal spinning and characterized using SEM, FTIR, XPS, DSC, XRD, and PL. Fibers luminescence response was gotten when induced by ultraviolet light and the application of an impact force.
Polymeric Pvdf Fibers For Piezoelectric Applications In Energy Harvesting, Misael E. Martinez
Polymeric Pvdf Fibers For Piezoelectric Applications In Energy Harvesting, Misael E. Martinez
Theses and Dissertations
This work focuses on developing and characterizing the piezoelectric response of Cerium doped Polyvinylidene Fluoride (PVDF) fine fibers and the effects of dopants and alignment on the formation of the β-phase and consequently on the piezoelectric performance. Six sets of fiber mats were prepared varying the concentration (2.5–7.5wt%) of Cerium (III) Nitrate-Hexahydrate and Ammonium-Cerium (IV) Sulfate-Dihydrate. Fiber mats were developed using the Forcespinning® technique and the angular velocity and dopant concentration were adjusted to obtain a synergy between fiber yield and fiber diameter. Fourier Transform Infrared Spectroscopy showed a significant enhancement in the PVDF β-phase and inhibition of the non-polar …
Blockchain Technology Based Supply Chain Systems And Supply Chain Performance: A Resource-Based View, Madhavi Latha Nandi
Blockchain Technology Based Supply Chain Systems And Supply Chain Performance: A Resource-Based View, Madhavi Latha Nandi
Theses and Dissertations
Blockchain technology (BCT) is set to transform firms’ present ways of managing supply chains. This thesis explores how the efforts by firms to integrate BCT into their supply chain systems and activities, can enable certain supply chain capabilities and subsequently, improve supply chain performance. Using an abductive research approach, qualitative content analyses of 126 cases of firms’ efforts in BCT-based supply chain systems (BCT-SCS) across multiple industries are conducted to identify the BCT-enabled supply chain capabilities and their performance outcomes. Findings reveal that the present BCT-SCS efforts are mainly oriented towards improving the operational-level capabilities namely, information sharing and coordination …
Fatigue Strength Evaluation And Fracture Behavior Of Joined Dual Phase Steel/Aa6061-T6 Aluminum Alloy, Ruben Perez Mora, Celso Eduardo Cruz Gonzalez, Saul Daniel Santillan Gutierrez, Jaime Taha-Tijerina, Benjamin Vargas Arista, Arturo Barba Pingarron
Fatigue Strength Evaluation And Fracture Behavior Of Joined Dual Phase Steel/Aa6061-T6 Aluminum Alloy, Ruben Perez Mora, Celso Eduardo Cruz Gonzalez, Saul Daniel Santillan Gutierrez, Jaime Taha-Tijerina, Benjamin Vargas Arista, Arturo Barba Pingarron
Informatics and Engineering Systems Faculty Publications
The fatigue strength evaluation and fracture behavior for a dual phase steel-AA6061-T6 bonded joints with three different adhesives (DC-80, Betamate 120 and MP55420) are presented in this paper. Single lap shear tests were used to determine maximum shear loads, for the single lap shear testing for 5.0 mm overlap length were 2 to 3.5 times higher in comparison to the 12.7 mm overlap length specimens. The results for the strain measurement revealed that higher strain-stress were developed in the 6061-T6 aluminum alloy adherend and in all cases they were lower than the adherends yield strength. Fatigue testing was carried out …
Linear Stability Analysis Of Subaqueous Bedforms Using Direct Numerical Simulations, Nadim Zgheib, S. Balachandar
Linear Stability Analysis Of Subaqueous Bedforms Using Direct Numerical Simulations, Nadim Zgheib, S. Balachandar
Mechanical Engineering Faculty Publications
We present results on the formation of ripples from linear stability analysis. The analysis is coupled with direct numerical simulations of turbulent open-channel flow over a fixed sinusoidal bed. The presence of the sediment bed is accounted for using the immersed boundary method. The simulations are used to extract the bed shear stress and consequently the sediment transport rate. The approach is different from traditional linear stability analysis in the sense that the phase lag between the bed topology and the sediment flux is obtained from the three-dimensional turbulent simulations. The stability analysis is performed on the Exner equation, whose …
Forcespinning Technique For The Production Of Poly(D,L-Lactic Acid) Submicrometer Fibers: Process–Morphology–Properties Relationship, Victoria Padilla-Gainza, Graciela Morales, Heriberto Rodríguez-Tobías, Karen Lozano
Forcespinning Technique For The Production Of Poly(D,L-Lactic Acid) Submicrometer Fibers: Process–Morphology–Properties Relationship, Victoria Padilla-Gainza, Graciela Morales, Heriberto Rodríguez-Tobías, Karen Lozano
Mechanical Engineering Faculty Publications
This work addresses a systematic study for the process development and optimization of poly(d,l-lactic acid) (PDLLA) submicrometer fibers utilizing the centrifugal spinning technique known as Forcespinning. This study analyzes the effect of polymer concentration (8, 10, and 12 wt %) and angular speed on the fiber morphology, diameter distribution, and fiber yield. The increase in polymer concentration and angular speed favored the formation of continuous and homogeneous submicrometer fibers with an absence of bead formation and higher output. The optimal conditions were established considering the morphological characteristics that exhibit a greater surface area (homogeneous and submicrometer fibers); and they were …
Electrical Properties And Electromagnetic Interference Shielding Effectiveness Of Interlayered Systems Composed By Carbon Nanotube Filled Carbon Nanofiber Mats And Polymer Composites, Claudia A. Ramirez-Herrera, Homero Gonzalez, Felipe De La Torre, Laura Benitez, Jose G. Cabanas-Moreno, Karen Lozano
Electrical Properties And Electromagnetic Interference Shielding Effectiveness Of Interlayered Systems Composed By Carbon Nanotube Filled Carbon Nanofiber Mats And Polymer Composites, Claudia A. Ramirez-Herrera, Homero Gonzalez, Felipe De La Torre, Laura Benitez, Jose G. Cabanas-Moreno, Karen Lozano
Mechanical Engineering Faculty Publications
The demand for multifunctional requirements in aerospace, military, automobile, sports, and energy applications has encouraged the investigation of new composite materials. This study focuses on the development of multiwall carbon nanotube (MWCNT) filled polypropylene composites and carbon nanofiber composite mats. The developed systems were then used to prepare interlayered composites that exhibited improved electrical conductivity and electromagnetic interference (EMI) shielding efficiency. MWCNT-carbon nanofiber composite mats were developed by centrifugally spinning mixtures of MWCNT suspended in aqueous poly(vinyl alcohol) solutions. The developed nanofibers were then dehydrated under sulfuric acid vapors and then heat treated. Interlayered samples were fabricated using a nanoreinforced …
Fabrication And Characterization Of Centrifugally Spun Poly(Acrylic Acid) Nanofibers, David De La Garza, Francisco De Santiago, Luis Materon, Mircea Chipara, Mataz Alcoutlabi
Fabrication And Characterization Of Centrifugally Spun Poly(Acrylic Acid) Nanofibers, David De La Garza, Francisco De Santiago, Luis Materon, Mircea Chipara, Mataz Alcoutlabi
Mechanical Engineering Faculty Publications
The production of poly(acrylic acid) (PAA) nanofibers by the centrifugal spinning of PAA solutions in water is reported. The effect of the spinneret rotational speed and concentration of PAA solutions on the diameter of nanofibers and on their quality (assessed by the absence of beads) is discussed. The main physical properties of PAA such as glass-transition temperature (Tg) are studied in detail and compared to the feature of the as-received homopolymer. It is shown that the glass-transition temperature of the bulk PAA and PAA nanofibers (as measured by differential scanning calorimetry) depends on the heating rate according …
The Educational Value Of Modelling Complex Thermodynamic Systems With System Dynamics Software, Stephen Crown, Constantine Tarawneh
The Educational Value Of Modelling Complex Thermodynamic Systems With System Dynamics Software, Stephen Crown, Constantine Tarawneh
Mechanical Engineering Faculty Publications
The solution of problems involving complex thermodynamic systems often occupies much of a students' time and can be a distraction from them developing a clear understanding of system components, interaction of subsystems, modelling simplifications and assumptions, and design optimization. Refocusing students on the fundamental concepts of thermal systems design and analysis is possible with the introduction of system modelling software that carries some of the load of repetitive calculation required for complex systems. Models of thermodynamic systems encountered in an advanced undergraduate thermodynamics course were developed by students (some provided to students) to solve homework problems of complex steam power …
Simulation Of Droplet Impacting A Square Solid Obstacle In Microchannel With Different Wettability By Using High Density Ratio Pseudopotential Multiplerelaxation- Time (Mrt) Lattice Boltzmann Method (Lbm), Wandong Zhao, Ying Zhang, Wenqiang Shang, Zhaotai Wang, Ben Xu, Shuisheng Jiang
Simulation Of Droplet Impacting A Square Solid Obstacle In Microchannel With Different Wettability By Using High Density Ratio Pseudopotential Multiplerelaxation- Time (Mrt) Lattice Boltzmann Method (Lbm), Wandong Zhao, Ying Zhang, Wenqiang Shang, Zhaotai Wang, Ben Xu, Shuisheng Jiang
Mechanical Engineering Faculty Publications
In this paper, a pseudopotential high density ratio (DR) lattice Boltzmann Model was developed by incorporating multi-relaxation-time (MRT) collision matrix, large DR external force term, surface tension adjustment external force term and solid-liquid pseudopotential force. It was found that the improved model can precisely capture the two-phase interface at high DR. Besides, the effects of initial Reynolds number, Weber number, solid wall contact angle (CA), ratio of obstacle size to droplet diameter ( 1 χ ), ratio of channel width to droplet diameter ( 2 χ ) on the deformation and breakup of droplet when impacting on a square obstacle …