Mechanical Engineering Commons^™

Real-Time Material State Assessment Of Composites Using Artificial Intelligence And Its Challenges, Muthu Ram Prabhu Elenchezhian

Mechanical and Aerospace Engineering Dissertations - Archive

Over several decades of careful experimental investigation and exhaustive development of discrete damage analysis methods including integrated computational mechanics methods, our community knows a great deal about how discrete defects such as matrix cracks and defect growth (e.g. delamination) can be predicted in structural composites. For many practical situations controlled by laminated multiaxial composite structures, the loss of performance and “sudden death” end of life is controlled by defect coupling which becomes a precursor to fracture plane development. These interaction sequences are highly dependent on local details of manufacture, design configurations, and loading for a given application material and influenced …

Cooling Efficiency Improvement Of A Data Center Using Optimized Cabinet Design And Hybrid Cooling With High Inlet Conditions Of Single-Phase Coolant And Air, Uschas Chowdhury

Mechanical and Aerospace Engineering Dissertations - Archive

The objective of this study is to improve and optimize the cooling efficiency of liquid and air cooling from server to room level while applying best practices in the industry. The effect of increased air and coolant temperature has been explored through a literature survey and studies are conducted from device level to room level for air and liquid cooling. Three major aspects are considered. A closed-form air cooling solution is proposed for high-powered racks in a modular data center equipped with in-row coolers. Direct-to-chip liquid cooling technology is extensively studied at the server level for raised air and coolant …

Impact Of Material Models On Immersion Cooled Electronics Packages And Reliability Assessment For Chip-Package Interaction, Tushar Jashvantbhai Chauhan

Mechanical and Aerospace Engineering Dissertations - Archive

The immersion cooling for IT equipment has been around for decades. From thermal energy management perspective, immersion cooling is better than traditional cooling technology. However, there is need for more work in open literature when it comes to impact of immersion cooling on the reliability of IT equipment to make it commercially implemented. Detailed study of material compatibility of the various electronics packaging materials for immersion cooling is essential to understand their failure modes and reliability. The stiffness and thermal expansion are critical material properties for electronics mechanical design. This part of the study mainly focuses on two things. The …

Development Of A Test Method For Characterizing An Indirect Evaporative Cooling Module For Data Center Cooling Application, Abhijit Rajendra Bhosale

Mechanical and Aerospace Engineering Theses - Archive

Evaporative cooling is a smarter way of maintaining optimum operating conditions in data centers. Indirect Evaporative Cooling (IEC) provides the advantage of cooling without changing the humidity of the Data Center (DC) air. We analyze and develop a method of testing to help build IEC modules at larger scales with improved characterization that is intended to help DC engineers achieve stringent Power Utilization Efficiency (PUE) targets by expending minimum power. We study the design parameters pertinent to sizing an IEC module used in DC cooling and develop a test method while technically selecting the components involved. The module is planned …

Sensitivity Study Of Calibrated Data Center Models To Minimize Site Survey Time Using Cfd, Saurabh Singh

Mechanical and Aerospace Engineering Theses - Archive

Data center (DC) consists of components like cooling pipes, data cables, power conduits, etc. To analyze the thermal behavior of DC using computational fluid dynamics, virtual model of DC is required. To build this virtual model, data is required regarding the different components like size, location and defining parameters. Site surveys are required to collect this data. Data collection is important to build an accurate model. There is lack of guidance with respect to which components are crucial to achieve level of accuracy in computational model. Sensitivity study can be used to determine accuracy achieved by introducing simplification in component …

Effectiveness Of Closed-Loop Inverse-Kinematic Landmark Navigation Method On Drifting And Heading Errors Of Imprecise Multi-Legged Robots, Thong Quang Nguyen

Mechanical and Aerospace Engineering Theses - Archive

This work addresses the effectiveness of a closed-loop inverse-kinematic control methodology on alleviating drifting and heading errors in the walking and turning of a hexapod robot. Most work in this area focuses on stability, hardware design, and control. This work is aimed at controlling imprecise hardware on unknown structured environments. The proposed controller uses a camera and an ultrasonic sensor as sensory feedback. It also uses the well-known tripod gait for locomotion, implemented with the closed-loop inverse-kinematic method. Experimental results show the effectiveness of this approach in walking and turning the hexapod on an unknown surface.

Thermal Design Analysis Of Server Chassis Manifolds For Liquid Cooled Servers Using Cfd, Kaustubh Kantilal Adsul

Mechanical and Aerospace Engineering Theses - Archive

Direct-to-chip liquid cooling is one of the most popular methods in data center thermal management when it comes to cooling high chip power densities. A cold plate-based liquid cooling system contains various components such as pumps, data center room, and rack-level manifolds, and server chassis-level manifold. Efficient coolant distribution to the heat-dissipating cold plates plays an important role in both the thermal and hydraulic performance of the server. It is, thus, very important to design and manufacture server chassis manifold geometry that can perform efficiently under the anticipated heat loads and coolant flow rates. In the present thesis, two such …

Design And Cfd Analysis Of A Tank Solution For Natural Convection Based Single-Phase Immersion Cooling Of Servers, Siddhesh Manohar Khanvilkar

Mechanical and Aerospace Engineering Theses - Archive

The issue of thermal management of data centers is becoming even more challenging with increasing chip power densities. This has been primarily driven by increasing demands in artificial intelligence and machine learning-based applications, increased usage of cloud-based services, and high-performance computing. The development of these applications has led to a corresponding increment in high performance and high power density CPUs and GPUs. Liquid cooling technologies are outperforming the traditional air cooling approach in dissipating high heat fluxes. Out of these technologies, single-phase immersion cooling offers advantages like substantially lower PUE values, simplified data center infrastructure, ease of deployment for edge …

Design, Development, And Characterization Of A Flow Control Device For Dynamic Cooling Liquid-Cooled Servers, Hardik Yashwant Hurnekar

Mechanical and Aerospace Engineering Theses - Archive

Since the early ’60s, based on Moore’s law, transistor density has been doubling every generation resulting in increased power density. Eventually, in the early ’90s, we moved from constant voltage to constant electric field and corresponding constant power for a given area during technology changes. Dennard’s model of voltage scaling and corresponding constant power ceased, ending improved performance gains in the early 2000s that again required techniques to mitigate increased power and corresponding temperature. The performance gain is being achieved by using multi-core processors, leading to non-uniform power distribution and localized high temperatures making cooling very challenging. Direct cold plate-based …

Evaluating The Thermal Performance Of Topology Optimized Low-Cost 3d Printed Heat Sink Made Of Copper, Bilal Taha

Mechanical and Aerospace Engineering Theses - Archive

The performance of a heat sink is highly dependent on the overall surface area available for heat transfer. Designing heat sinks with greater surface areas meant bigger size, weight, and volume of heat-exchanger thus making it unfeasible to produce. Design and manufacture of compact-sized heat sinks is a difficult task, as it would require the use of complex surface modeling and complex surface cutting. But with the advent of 3D printing technology, it has become easier to manufacture heat sinks having complex designs producing larger surface areas as they add material layer by layer rather than cutting it away. The …

Investigation On Microstructure And Mechanical Properties Of Porous Structures Processed By Laser Powder Bed Fusion, Samarth Ramachandra

Mechanical and Aerospace Engineering Theses - Archive

Inconel 718 (i.e., IN718) is a prominent nickel-based, precipitation-hardening superalloy which exhibits exceptionally stable mechanical and corrosion resistant properties, even at temperature range of 650ºC to 700ºC, making it suitable for a wide range of applications such as aerospace, nuclear reactors, tooling, turbines, oil and gas applications. The high toughness and work hardening offered by this superalloy, however, greatly limits the choice of machinability. The presence of low levels of aluminum permits good weldability which further allows the use of laser-based additive manufacturing (AM) to efficiently fabricate IN718 parts without the limitations associated with conventional manufacturing methods. Thanks to AM …

Investigation Of The Microstructural And Mechanical Properties Of Selectively Laser Melted In718 Overhangs Fabricated Without Support Structures, Manjunath Hanumantha

Mechanical and Aerospace Engineering Theses - Archive

Additive manufacturing is a new manufacturing technology that allows for extreme design freedom as well as the simultaneous production of many parts with high complexities. IN718 is a high-strength, corrosion-resistant super alloy of nickel and chromium. It is ideal for high-end applications such as rocket nozzles and turbines because it can handle exceptionally high pressure and heat. Because of its high stiffness qualities, conventional manufacturing of complex IN718 geometries is challenging. Various fabrication techniques have been developed, and this study focuses on selective laser melting (SLM) because of its potential to produce near-perfect parts at a low cost when working …

Structural Optimization And Reliability Assessment Of Heterogeneous 3d Ic Packages And Analysis Of Rheological Properties Of Particle Based Thermal Interface Materials, Mehzabeen Binte Kabir

Mechanical and Aerospace Engineering Theses - Archive

As computing and communication devices are converging with improved functionally, denser, and finer pitch which creates complexity of circuit interconnections for 2-D devices becomes a limitation for overall performance and drives up power dissipation [1]. Thus the ordinary 2-D structures of IC packages cannot address those demands where 3-D through-silicon via (TSV) is the key to 3-D IC integration and stacking of chips, is emerging now as a powerful tool to converge the needs of integrated circuit (IC) packages. In 3D TSV the chips are stacked on top of another so heat trapped in a small region which is difficult …

Designing Cryogenic Strain Device For 2d Materials, Jake Carter

Mechanical Engineering Undergraduate Honors Theses

The Churchill lab working within the Physics Department at the University of Arkansas is working to create important quantum states including weak topological insulators (TIs) through the use of symmetry engineering and topological electronic states in two-dimensional (2D) crystals of WHM materials. Experimental results of these topological states have been obstructed due to the difficulty to perform controlled in situ strain. This project strives to create a mount to utilize a piezoelectric nanopositioner within cryostats achieving an in situ strain that creates the quantum states the lab is looking to observe. This report also examines the necessary equations to determine …

Design And Optimization Of An Array Of Hollow Micropillar Structures For Enhanced Evaporative Cooling, Zhikai Yang

McKelvey School of Engineering Graduate Student Theses & Dissertations

With the increasing demand for higher-performance chips, the architecture of these semiconductor devices becomes more complex, leading to the need for higher-performance cooling technologies. For example, 3D stacked chips offer several advantages, including mixed functionality, reduced signal delay, and a smaller footprint. However, these devices yield higher heat densities due to the heat compounded from one stacked die to the next. While traditional single-phase cooling technologies can dissipate large heat fluxes, its performance is inversely proportional to its hydraulic diameter leading to larger required pumping powers. Two-phase cooling is a promising technique for dissipating high heat fluxes by utilizing the …

Economic Feasibility Of Mixed Plastic Waste Pyrolysis Using Twin Reactor System In Northwest Arkansas, Carol Rogers, Patricia Means, Renato Gonzalez, Kaida Sheets, Hayden Townsend

Chemical Engineering Undergraduate Honors Theses

Plastic waste generation is increasing at an unsustainable rate while recycling solutions remain stagnant. As a chemical means of recycling, mixed plastic waste pyrolysis can generate synthetic oil appropriate for use as fuel in power generation from plastic waste that otherwise accumulates in landfills. With the scaling of a commercial plastic pyrolysis process in Northwest Arkansas (NWA) modeled after an operational sawdust pyrolysis unit in Huntsville, Arkansas, economic analysis resulted in 26.3% internal rate of return. Therefore, construction of a commercial mixed plastic-to-fuel pyrolysis plant is economically justified and should be pursued. To effectively implement the proposed design, NWA must …

Development Of A Variable Extensometer Method For Measuring Ductility Scaling Parameters, Adam J. Smith

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Ductility is the measure of how much a material can stretch before separation. It is usually measured in percent elongation, which is the amount a material stretches divided by its original length before stretching. This is an important property to understand for both the design for performance and safety. A material’s ductility can be influenced by several factors including heat treatment, machining, temperature, and radiation dose. Materials used in nuclear energy facilities are often exposed to all these factors, and it is important to be able to understand ductility at each possible combination.

Ductility is usually characterized through tension tests …

Potential Improvements For Underwater Sound Speed Measurement Devices, Matthieu Bernier

Honors Scholar Theses

Modern sonar systems rely on fast and accurate measurements of the speed of sound in water. Plenty of measurement devices currently exist which are used to gather sound speed measurements in water. They specifically require accurate temperature measurements, as temperature is the most influential factor which affects sound wave speed. Previous research on sound speed properties, a few different examples of sound speed measurement devices, and examples of different types of temperature measurement devices was used along with new research on salinity equations and properties of sound, ocean water, and various existing measurement devices to suggest possible improvements for sound …

Evaluation Of Flared Approach Guardrail Transitions And Mash 2270p Ram Vehicle Model Improvements, Ryan F. Bickhaus

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

The objective of this research study was to use computer simulation to identify the critical flare rate for flaring approach guardrail transitions (AGTs) away from the primary roadway. AGTs installed with a flared configuration result in a length of need (LON) reduction as well as an increase in the clear zone area in front of the barrier, which would reduce both installation cost and crash frequency. The research focused on the determination of the maximum allowable flare rate that could safely be utilized with 31-in. (787-mm) tall thrie-beam AGTs without concrete curbs that utilize the Midwest Guardrail System (MGS) upstream …

Propeller And Propeller-In-Wing Thrust Vectoring, Grace G. Culpepper

Honors Theses

This research investigates the efficiency of a vane-based thrust vectoring system set in the wake of a propeller, supporting forward force at a minimum loss in net thrust. The vectoring system itself is placed in both a standalone propeller configuration and a propeller-in-wing configuration. Both static and wind-on force-based experiments are conducted at the University of Dayton Low Speed Wind Tunnel (UD-LSWT) with off-the-shelf R/C propellers. Sensitivity analysis determines both the effect of vane deflection angle on thrust vectoring and the effect of propeller placement with respect to the upper surface of the integrated wing on system performance. Static test …

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 …

Synthesis And Characterization Of Functiona Materials For 3d Printed Composites, Elizabeth Irene Reza

Open Access Theses & Dissertations

The following body of work encompasses the synThesis, upscaling, additive manufacturing, and characterization of microspheres as functional fillers incorporated into polymer syntactic foams. Synthesizing microspheres permits control over morphology, dispersion of particles, and size while the use of direct write manufacturing allowed for the controllability of filler orientation. Two different syntactic foams were developed from similar methodologies: (1) a silicone syntactic foam (2) epoxy syntactic foam. The silicone epoxy foam showed an increasing in damping and elastic modulus. The epoxy syntactic foams showed an enhanced thermal and electrical properties.

Improving The Impingement Cold Plate Thermal Design Using Numerical And Analytical Approach, Reuben Joshua Madhuker

Mechanical and Aerospace Engineering Theses - Archive

Conventional cooling methods for an IC chip uses heat spreader to transfer heat from the chip end of the spreader to the opposite end of the spreader which then uses air or water to remove heat and thereby maintaining the overall temperature. Unfortunately, the heat spreader itself has constraints such as conduction resistance which adds the heat spreader inefficiency. But if we increase the area exposed to the cooling end then this can be improved. This is done by introducing channels at that end. These channels act as fins which give a better shot at cooling the system temperature. These …

Apiary Wagon Frame, Katelyn Franklin, Ryoma Thomas

Honors Theses

The objective of this thesis to demonstrate how our senior capstone project team took a product from a concept to a mass production manufacturing operation, using the knowledge and experience gained through our four years in the Haley Barbour Center for Manufacturing Excellence (CME). Our product, the Apiary Wagon Frame, is an opportunity to reduce the barrier to entry into the hobbyist beekeeping community. In the design process for the Apiary Wagon Frame, we tested several prototypes and different fabrication methods, ending with a product capable of holding twenty hive frames. After building our final prototype, the group created a …

Economic Feasibility Of A Methanol To Dimethyl Ether Production Process To Avoid Contract Failure Shortfalls From The Covid-19 Pandemic, Jacob Noll, Robert Wasson, Harrison Mckinnis

Honors Theses

Our team entered the 2021 AVEVA Academic Competition, where teams of undergraduate senior chemical engineering students competed across the country. The competition was composed of two parts: the base case design and the optimization of a chemical process. As part of the competition, our team is acting as the Engineering team for a fictional company that has given us this project. Due to COVID-19, our methanol producing company has lost a contract with a customer, leaving 23,000 tonnes/yr of unclaimed methanol. We have two choices with this methanol: either sell the methanol on the market at the spot price for …

Creation Of A Wooden Model Toy Car As A Learning Module For Students Enrolled In Manufacturing 152, Patrick Brown

Honors Theses

This project involved the design and manufacture of a children’s wooden model toy car constructed on the CME factory floor. Apart from building a children’s toy, the purpose of this project was to introduce younger CME students to a high-quality product made efficiently in regards to manufacture time and total cost. The design for the car required the inclusion of principles from different manufacturing philosophies taught in the CME such as LEAN Manufacturing, which works to eliminate waste from a process, and Design for Manufacture and Assembly, which seeks to reduce cost and cycle time for a product. Through the …

A Model-Based Approach To Predict Neuromuscular Control Patterns That Minimize Acl Forces During Jump Landing, Dieter Heinrich, Antonie J. Van Den Bogert, Robert Csapo, Werner Nachbauer

Mechanical Engineering Faculty Publications

Jump landing is a common situation leading to knee injuries involving the anterior cruciate ligament (ACL) in sports. Although neuromuscular control is considered as a key injury risk factor, there is a lack of knowledge regarding optimum control strategies that reduce ACL forces during jump landing. In the present study, a musculoskeletal model-based computational approach
is presented that allows identifying neuromuscular control patterns that minimize ACL forces during jump landing. The approach is demonstrated for a jump landing maneuver in downhill skiing, which is one out of three main injury mechanisms in competitive skiing.

Validation Of A Two-Dimensional Clinostat Design To Provide Functional Weightlessness To Custom Gas Exchange Vessels, Collin R. Topolski

Doctoral Dissertations and Master's Theses

Understanding the impacts of microgravity on bacteria is vital for successful long duration space missions. In this environment, bacteria have been shown to become more virulent, more resistant to antibiotics and form more biofilms. To learn more about these phenomena, many experiments must be sent to the International Space Station, which is cost- and time prohibitive. Instead, the use of ground-based analogs is advantageous to define preliminary results that can later be verified with a space-based experiment. This research explored the development of an innovative 2D clinostat for simulating microgravity using bacteria. Computational fluid dynamics, standards established by previous literature …

Fluid Powered Vehicle Challenge: Team Soulenoid Cycle, Kellen Muir Giuliani, Jordan David Kochavi, Cayla Renee Quinn, Martin Reyes

Mechanical Engineering

The National Fluid Power Association is a trade association that unifies customers and manufacturers within the hydraulics industry. Extending their partnership to universities, the annual Fluid Powered Vehicle Competition challenges college teams to design, build, and test a fluid-powered vehicle with the goal of educating students about the hydraulics industry and building career connections. Soulenoid Cycle produced the next iteration of Cal Poly’s fluid powered vehicle for the 2021 competition.

This report summarizes research, ideation, component selection, initial and final design, manufacturing, and competition results conducted by Soulenoid Cycle. Relevant research includes successful current and past vehicles, the operation of …

Mathematical Modeling Of A Two Wheeled Robotic Base, Kathryn Remell

Mechanical Engineering Undergraduate Honors Theses

This thesis presents the concept of using a two wheeled robot on the moon and briefly explores the requirements for successful long term operation in a lunar environment. The mathematical model for the motion of a robot with two fixed wheels on a differential drive with in a global reference frame. The robot is assumed to be balancing a platform so the mathematical model to balance the platform with wheel motors is also developed and briefly evaluated.