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Effect Of Surface Fluid Entrapment In A Laminar Flat Plate Boundary Layer, Abigail Hays

Mechanical Engineering Research Theses and Dissertations

For streamlined objects in laminar flow, the drag is dominated by friction drag. To counteract this, the boundary condition of the object can be changed to introduce an apparent slip on the surface. A number of approaches have been proposed for introducing surface slip to reduce drag and viscous resistance in fluid flows. This work investigates a novel approach to providing slip via fluid entrapment in a perforated domain embedded in the surface. The fluid entrapment system uses a cavity underneath the domain to allow entrapment of fluid of the same type, or supply air to the surface perforations in …

A Review Of Solar Hybrid Photovoltaic-Thermal (Pv-T) Collectors And Systems, Todd Otanicar

Mechanical and Biomedical Engineering Faculty Publications and Presentations

In this paper, we provide a comprehensive overview of the state-of-the-art in hybrid PV-T collectors and the wider systems within which they can be implemented, and assess the worldwide energy and carbon mitigation potential of these systems. We cover both experimental and computational studies, identify opportunities for performance enhancement, pathways for collector innovation, and implications of their wider deployment at the solar-generation system level. First, we classify and review the main types of PV-T collectors, including air-based, liquid-based, dual air–water, heat-pipe, building integrated and concentrated PV-T collectors. This is followed by a presentation of performance enhancement opportunities and pathways for …

Automated Fiber Placement Through Thickness Defect Stacking Optimization, Noah Christopher Swingle

Theses and Dissertations

In its 2022 commercial market outlook, Boeing forecasted an 80% increase in the global fleet through 2041 compared to 2019 pre-pandemic levels. This sharp rise in demand will drive pressure onto airframe manufacturers to ramp up production and find more efficient ways to design and manufacture airplanes. Complicating this challenge is the industry’s recent transformation from traditional metal-based airframes towards hybrid composite-metal aircraft. While composites have been used in aviation for decades, aircraft manufacturers are still struggling to design and manufacture quality parts at a high rate. Automated Fiber Placement (AFP) is one of the main manufacturing techniques used to …

Modeling, Control, And Hardware Development Of A Thrust-Vector Coaxial Uav, Andrew North

Doctoral Dissertations and Master's Theses

This thesis introduces a unique thrust vector coaxial unmanned aerial vehicle (UAV) configuration and presents a comprehensive investigation encompassing dynamics modeling, hardware design, and controller development. Using the Newton-Euler method, a dynamic model for the UAV is derived to gain in-depth insights into its fundamental flight characteristics. A simple thrust model is formulated and modified by comparing it with data obtained from vehicle testing. The feasibility of manufacturing such a vehicle is assessed through the development of a hardware prototype. Finally, a linear state feedback controller is designed and evaluated using the non-linear dynamics model. The results demonstrate successful validation …

Image Segmentation With Human-In-The-Loop In Automated De-Caking Process For Powder Bed Additive Manufacturing, Vincent Opare Addo Asare-Manu

Theses and Dissertations

Additive manufacturing (AM) becomes a critical technology that increases the speed and flexibility of production and reduces the lead time for high-mix, low-volume manufacturing. One of the major bottlenecks in further increasing its productivity lies around its post-processing procedures. This work focuses on tackling a critical and inevitable step in powder-bed additive manufacturing processes, i.e., powder cleaning or de-caking. Pressing concerns can be raised with human involvement when performing this task manually. Therefore, a robot-driven automatic powder cleaning system could be an alternative to reducing time consumption and increasing safety for AM operators. However, since the color and surface texture …

Gpu-Enabled Genetic Algorithm Optimization And Path Planning Of Robotic Arm For Minimizing Energy Consumption, Yichuan Cao

Theses and Dissertations

The robotic arm represents a complicated mechanical system and advanced engineering principles in robotics, enabling precise and efficient manipulation and interaction with objects in a variety of applications, such as manufacturing, healthcare, space exploration, and other industries. In most cases, energy consumption of robotic tools has been given little consideration due to their perceived insignificance compared to the benefits they offer. However, the increasing capacity demands of factories and the expanding use of robotic arms necessitate careful evaluation and reduction of energy consumption. In this regard, given a task configuration, adjusting the arm's movement path emerges as one of the …

Development Of Atomistic Machine Learning Approaches For Thermal Properties Of Multi-Component Solids And Liquids, Alejandro David Rodriguez

Theses and Dissertations

Currently, heat transfer in many industries is the limiting factor for innovation, especially in the energy sector. For example, maximizing thermal conductivity of ceramic coatings in power plant devices improves the overall electrical to thermal energy ratio, whereas minimizing thermal conductivity is required for desirable heat-to-electricity conversion in thermoelectric devices. As such, rapid discovery of new materials with extreme thermal conductivity values is quintessential for the near-future deployment of current and developing energy applications.

The vibrational properties of crystalline materials are essential for their ability to conduct heat. Fundamentally, the restorative atomic forces of displaced atoms are sufficient to represent …

Tribological Behavior Of Polydopamine/Polytetrafluoroethylene Coating On Laser Textured Stainless Steel With Hilbert Curves, Firuze Soltani-Kordshuli, Nathaniel Harris, Min Zou

Mechanical Engineering Faculty Publications and Presentations

Shallow Hilbert curve patterns with easily programmable texture density were selected for laser texturing of stainless steel substrates. Two different texture path segment lengths (12 and 24 mu m) and four different laser power percentages (5%, 10%, 15%, and 20%) were investigated. The textured and smooth substrates were coated with thin polydopamine/polytetrafluoroethylene (PDA/PTFE) coatings for tribological property assessment. The effects of texture density (texture area coverage) and laser power on the durability and friction of the coated surfaces were studied. Laser texturing the substrates improved the coating durability up to 25 times, reduced the friction coefficient, and prevented coating global …

Kinetic Particle Simulations Of Plasma Charging At Lunar Craters Under Severe Conditions, David Lund, Xiaoming He, Daoru Frank Han

Mathematics and Statistics Faculty Research & Creative Works

This paper presents fully kinetic particle simulations of plasma charging at lunar craters with the presence of lunar lander modules using the recently developed Parallel Immersed-Finite-Element Particle-in-Cell (PIFE-PIC) code. The computation model explicitly includes the lunar regolith layer on top of the lunar bedrock, taking into account the regolith layer thickness and permittivity as well as the lunar lander module in the simulation domain, resolving a nontrivial surface terrain or lunar lander configuration. Simulations were carried out to study the lunar surface and lunar lander module charging near craters at the lunar terminator region under mean and severe plasma environments. …

Algorithms For The Generalized Inverse Solution And Direct Solution: Using An Algebra Computer-Based System To Obtain Meridian Arc Length, Wei-Kuo Tseng, King-Cheng Tsai, Chian Liou, Jiunn-Liang Guo, Yi-Jia Sun

Journal of Marine Science and Technology–Taiwan

In this study, the idea employed in the article of [1] to treat the problem of the arc-length of meridian is applied to the arc-length determined by the third flattening (n) instead of the eccentricity (e) of an Earth-reference ellipsoid . With WGS 84 ellipsoid datum used in modern navigation, the meridian arc-length is a crucial factor for map projections and geodetic and distance calculations such as Mercator charts, the universal transverse Mercator, great circle (ellipse), rhumb line, and geodesic. Because navigation software lacks officially standardized calculation methods, these “black box solutions” used in navigational systems are unknown. Therefore members …

Three-Dimensional Higher-Order Compressive Sensing For Raypath Separation In An Acoustic Waveguide, Fengyan Zhong

Journal of Marine Science and Technology–Taiwan

In an acoustic waveguide, the separation of multiple raypaths, especially close raypaths, is a challenging task in the presence of colored noise due to interference in the acoustic eld. In this paper, a three-dimensional higher-order compressive sensing method for raypath separation is proposed. The method is applied on an array-to-array experimental conguration where both emitter and reception arrays are used. With the array-to-array conguration, the raypaths are characterized by three parameters including arrival direction, departure direction, and arrival time. Furthermore, the performance of the proposed algorithm is illustrated by simulations and experiments. The numerical results based on simulation illustrate that …

Projection Of Sea Surface Temperature Based On Empirical Mode Decomposition And Its Application In Typhoon Number Forecast, Wen-Cheng Huang, Jung-Chen Lee

Journal of Marine Science and Technology–Taiwan

The primary objective of this paper is to demonstrate the applicability of empirical mode decomposition (EMD) in projecting non-stationary daily sea surface temperature (SST) series, and the other is to apply the projected series of SST to estimate the number of typhoons. The study focuses on an area ranging from 5°N~25°N and 110°E~170°E, collecting daily sea temperature data and typhoons records within this region. The findings conclusively indicate that the EMD-based data generation method proposed in this paper can effectively addresses the limitations of previous hydrological models in generating non-stationary series, signifying a significant advancement in hydrological time series modeling …

Smart Grid In Tanzania: Research Opportunities, Aviti Thadei Mushi

Tanzania Journal of Engineering and Technology (TJET)

reinvigorated its power generation capacity significantly to ensure smooth execution of its industrialization agenda and cope with the fourth industrial revolution. To ensure reliable availability of power to sustain its growing economy, Tanzania embarked on a deliberated measure to forge an energy mix. This deliberate measure encompasses the use of renewable energy technologies such as wind, solar, biomass, wastes, and micro hydro; natural gas; and other energy sources which are locally available including coal and geothermal. To effectively and efficiently manage such a growing power system and make electricity accessible to all for higher levels of industrial investment and services, …

Design And Development Of Ultrabroadband, High-Gain, And High-Isolation Thz Mimo Antenna With A Complementary Split-Ring Resonator Metamaterial, Ammar Armghan, Khaled Aliqab, Meshari Alsharari, Osamah Alsalman, Juveriya Parmar, Shobhit K. Patel

Department of Mechanical and Materials Engineering: Faculty Publications

The need for high-speed communication has created a way to design THz antennas that operate at high frequencies, speeds, and data rates. In this manuscript, a THz MIMO antenna is designed using a metamaterial. The two-port antenna design proposed uses a complementary splitring resonator patch. The design results are also compared with a simple patch antenna to show the improvement. The design shows a better isolation of 50 dB. A broadband width of 8.3 THz is achieved using this complementary split-ring resonator design. The percentage bandwidth is 90%, showing an ultrabroadband response. The highest gain of 10.34 dB is achieved …

Bend And Not Break: Examining Hispanic Engineering Student's Academic Challenges During Covid-19, Eleazar Marquez, Samuel Garcia

Mechanical Engineering Faculty Publications

Student success in higher education remains an area of interest, particularly for underrepresented minorities. Studies reveal that while Latino college enrollment has increased, retention rates continue to be an ongoing struggle. Several factors that attribute to such low rates include academic self-concept, family support, cognitive mapping, managing resources, background characteristics, and separation and maintenance of family ties. In the wake of COVID-19, most institutions responded by terminating in-person instruction, mandating to seek off-campus housing, and shifting to a fully remote context. As such, students were unable to utilize campus resources and engage in established educational campus practices. In this research …

Learning In Transition: Developing And Employing Pedagogical Supports To Enhance Student Learning In Engineering Education, Eleazar Marquez, Samuel Garcia

Mechanical Engineering Faculty Publications

Scholarly research indicates that classroom environment and conditions influence the degree of student learning, levels of engagement, and overall success in engineering education. In the wake of COVID-19, educational institutions transitioned to fully online delivery that disrupted traditional and effective channels of communication enacted in classroom contexts. For a substantial number of faculty members, this rapid transition to a fully remote instructional context marked the start a novel style of teaching and learning environment, a grand departure from the traditional, direct face-to-face setting. Such rapid and disruptive change required creative solutions to routinized instructional practices and compelling faculty to adjust …

Leveling The Playing Field: Enacting Equitable Pedagogy To Teach Rigid Body Dynamics, Eleazar Marquez, Samuel Garcia

Mechanical Engineering Faculty Publications

Research examining the quality of engineering programs across different instructions of learning has revealed that no two programs are alike. Each program has unique and distinctive features that influence the quality and rigor of education that students receive. Institutional culture, leadership, faculty preparedness, funding and many other factors influence program quality. Additionally, researchers have also noted that many institutional gaps and equity related issues are persistent and troublesome facets that further exacerbate the academic gaps in STEM education. It is within this context, that students attending top tier universities will likely have remarkedly vast academic experiences in terms of level …

Keeping Calm And Staying Balanced: Exploring The Academic Pressures Faced By Engineering Students To Attain High Grades And Their Impact On Mental Health, Eleazar Marquez, Samuel Garcia

Mechanical Engineering Faculty Publications

Studies reveal that grades have a short-term impact on students’ self-efficacy, motivation, and decision making. Earning high grades has become a focal point for engineering students to secure three types of opportunities: internships, post-graduation employment, and graduate school acceptance. Nonetheless, the desire to attain a competitive grade-point-average may lead to negative psychosocial effects such as increased mental exertion, physical exhaustion, anxiety, and overall lack of work-life balance. In this paper, the authors extend their prior study on the impact of grades in engineering education. The first study was conducted in the spring of 2019 at a tier one, small private …

Advances In Multiagent Systems Control: Multiplex Information Networks-Based Approaches And Beyond, Kimberly Witke

USF Tampa Graduate Theses and Dissertations

Multiagent systems control designs offer numerous advantages to increasingly complex civilian, military, and scientific tasks ranging from intelligent satellite swarm controls or autonomous traffic controls to remote triage and repair or remote wildlife observation, where the performance of a single agent is insufficient to execute the task at hand. Traditional methods in multiagent systems controls, however, have been infeasible for use in scalable, large-group formation controls.

With this in mind, the contribution of this dissertation is to bridge the gap in knowledge through both theoretical and experimental validation of multiagent systems control architectures. It addresses the challenges presented by unreliable, …

Metachronal Locomotion: Swimming, Scaling, And Schooling, Kuvvat Garayev

USF Tampa Graduate Theses and Dissertations

This dissertation deals with one type of underwater locomotion called metachronal swimming in which the organism sequentially beats its multiple appendages allowing phase lag between adjacent neighbors. Metachronally swimming species are widespread and include copepods, shrimp, ctenophores, and tomopterid worms to name few. First, using the high-speed recording and planar particle image velocimetry (PIV) measurement, I report on kinematics of fast metachronal swimmer and constructive vortex interactions among its appendages and discuss its implications for improved performance regarding the swimming. Second, I show how hydrodynamic performance of all metachronal swimmers (paramecia, copepods, tomopterid worms, krill etc.) can be scaled by …

Aiaa Design, Build, Fly: Aerodynamics, Julian Brown, Victor Bueno Garcia, Kyle Lam, Keaton Viadro

Mechanical Engineering Senior Theses

As part of the Santa Clara University Senior Design Project, the AIAA Design, Build, Fly: Aerodynamics team was responsible for designing and testing the wings, tail, and control surfaces of an aircraft designed to participate in future AIAA Design, Build, Fly competitions. Named Evergreen in honor of professor John J. Montgomery, the unmanned aerial vehicle was designed and constructed in collaboration with the AIAA Design, Build, Fly: Structures and Controls senior design team. Aiming to construct a competitive aircraft for the competition, the team decided that a target weight of approximately 3.5 kg and a cruise speed of 25 m/s …

Coordinating Tethered Autonomous Underwater Vehicles Towards Entanglement-Free Navigation, Abhishek Patil, Myoungkuk Park, Jungyun Bae

Michigan Tech Publications, Part 1

This paper proposes an algorithm that provides operational strategies for multiple tethered autonomous underwater vehicle (T-AUV) systems for entanglement-free navigation. T-AUVs can perform underwater tasks under reliable communication and power supply, which is the most substantial benefit of their operation. Thus, if one can overcome the entanglement issues while utilizing multiple tethered vehicles, the potential applications of the system increase including ecosystem exploration, infrastructure inspection, maintenance, search and rescue, underwater construction, and surveillance. In this study, we focus on developing strategies for task allocation, path planning, and scheduling that ensure entanglement-free operations while considering workload balancing among the vehicles. We …

Fungi In Flux | Designing Regenerative Materials And Products With Mycelium, Arvind Bhallamudi

Masters Theses

As the world grapples with the escalating crisis of climate threats and environmental degradation, this research delves into the synergistic potential of design and biology, developing safe and sustainable materials for applications in prototyping, furniture and interior design. Harnessing the power of a unique organism - fungi, the study proposes an accessible, efficient, and resilient material resource system. It utilizes local waste streams and mycelium (the vegetative part of fungi) to grow functional structures. An experimental and small-scale protocol is modeled by testing bio-fabrication and bio-printing methods. The composites' performance qualities and characteristics are evaluated through mechanical testing and a …

A High-Speed Portable Ground Heat Exchanger Model For Use In Various Energy Simulation Software, Ryan Davies, Matt Mitchell, Edwin Lee

Macalester Journal of Physics and Astronomy

A portable component model (PCM) of a ground source heat pump system was developed and used as a test case in the creating of a PCM development framework. By developing this framework, new building energy simulation models will be able to be easily integrated into existing simulation software such as EnergyPlus and the Modelica Buildings Library. Our model uses a time responsive g-function and numerical methods to simulate ground source heat pumps for single time steps as well as long time scales. We validated our model against GHESim and GLHEPro and found that our model agrees with these two standards …

Morphology And Hemodynamics Of Cerebral Arteries And Aneurysms In A Rare Pair Of Monozygotic Twins, Hang Yi, Zifeng Yang, Luke C. Bramlage, Bryan R. Ludwig

Mechanical and Materials Engineering Faculty Publications

In this preliminary study, the underlying pathophysiology mechanisms of cerebral aneurysms (CAs) in monozygotic twins (MTs) were investigated via a rare pair of MTs (twin A and twin B) involving four reconstructed arterial models using preclinical information. First, dimensions and configurated outlines of three-perspective geometries were compared. Adopting an in-vitro validated numerical CA model, hemodynamic characteristics were investigated in the MTs, respectively. Despite expected genetic similarities, morphological comparisons show that configurations of cerebral arteries exhibit significant differences between the twins. The ICA size of twin A is larger than that in twin B (2.23~25.86%), varying with specific locations, attributing to …

3d Printed Poly Lactic Acid Structures For Cell Growth And Nanoparticle Transport-Simulation And Experimental Validation, Shrikrushna Vinayak Sonawane

Masters Theses

In today's world, 3D printing or additive manufacturing (AM) is being widely used in various fields due to its benefits such as rapid prototyping, reduced material waste and energy usage, lower cost, and more. Even the tissue engineering field is utilizing this technology. This study focused on examining the compatibility of 3D printed Lab-on-a-Chip structures made of Poly Lactic Acid (PLA) for in-vitro applications. In this research, the Lab-on-a-Chip structures were designed and created using 3D printing. To achieve the required bio-functionality scaffold surface was customized by post-printing processes such as mechanical polishing, hydrolysis (Wet Chemical Etching), and ultraviolet light …

Prove Primary Battery Structure, John D. Burkhart, Andy Mccormick, Ryan Yu, Soren Barclay

Mechanical Engineering

In conjunction with Prototype Vehicle (PROVE) Laboratory, our group designed, manufactured, and tested a prototype structure to house the battery boxes for PROVE’s endurance vehicle. Our structure was designed to support the batteries during normal use, and in the event of a front crash. Our design is comprised of a secondary composite box to house the battery boxes, a bottom plate to affix the secondary box to the chassis floor, a horizontal plate fastened to the chassis, and a brace structure welded to the chassis. From the outset, we chose to use a secondary box, the primary battery boxes must …

A Hybrid Admm For Six-Degree-Of-Freedom Entry Trajectory Optimization Based On Dual Quaternions, Chaoying Pei, Changhuang Wan, Ran Dai, Jeremy R. Rea

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This article investigates the six-degree-of-freedom (6-DoF) entry trajectory optimization problem in a Human-Mars entry, powered descent, and landing mission. During the entry phase, aerodynamic forces are employed to decelerate the vehicle. Instead of being treated as a point mass, both translational and rotational motions of the entry vehicle are considered. Specifically, the 6-DoF rigid body motion of the entry vehicle is modeled using the unit dual quaternion representations to avoid highly nonlinear terms in the flight dynamics expression originally based on the flight-path coordinates. Then, the entry trajectory optimization problem is to minimize the terminal speed subject to dynamical, operational, …

Gradient-Based Trade-Off Design For Engineering Applications, Lena A. Royster, Gene Hou

Mechanical & Aerospace Engineering Faculty Publications

The goal of the trade-off design method presented in this study is to achieve newly targeted performance requirements by modifying the current values of the design variables. The trade-off design problem is formulated in the framework of Sequential Quadratic Programming. The method is computationally efficient as it is gradient-based, which, however, requires the performance functions to be differentiable. A new equation to calculate the scale factor to control the size of the design variables is introduced in this study, which can ensure the new design achieves the targeted performance objective. Three formal approaches are developed in this study for trade-off …

Enabling Energy Efficiency In Connected And Automated Vehicles Through Predictive Control Techniques, Farhang Motallebiaraghi

Dissertations

The transportation sector is a significant contributor to global energy consumption and emissions, necessitating the development of sustainable transportation systems. In this regard, connected and automated vehicles (CAVs) have emerged as a potential solution to transform the transportation industry. By harnessing advanced mapping and location technologies, Vehicle-to-Vehicle (V2V) and Vehicle-to-Infrastructure (V2I) communication, CAVs offer the promise of improving efficiency, reducing traffic congestion, and enhancing safety and comfort. However, the adoption of CAVs also brings about various challenges, including energy efficiency concerns that need to be addressed to fully realize their potential benefits. This dissertation investigates energy-efficient control techniques for transportation …