Mechanical Engineering Commons^™

Design Of Multi-Objective And Optimal Sliding Mode Controller For Tracking Knee Joint Angle During Squatting And Normal Gait Motion, Gabriel Sitler

Theses, Dissertations and Capstones

This work presents two objectives for the use of robust sliding mode controller (SMC) in optimal and multi-objective settings to regulate the position of the knee joint angle for patients suffering from knee injuries. The controller imitates the role of active orthoses that produce the joint torques required to overcome gravity and loading forces and regain natural human movements. The first objective is to focus only on the knee, for which a mathematical model of the shank, the lower part of the leg, is derived first and then used for the control system design and computer simulations. Four objectives are …

Numerical Design, Fabrication, And Characterization Of Porous Tissue Scaffolds For Bone Regeneration, Brandon Coburn

Theses, Dissertations and Capstones

With the recent advancements within biomedical engineering of bone tissue scaffolds, there is still a need to develop mechanically robust and biocompatible with low immunogenicity for bone regeneration. Additionally, the evaluation of the fluid dynamics of the porous Triply Periodic Minimal Surfaces (TPMS) bone scaffold also shows the need for investigation due to the complex fluid interaction of hemodynamics that occurs with the scaffold internal and external domains. To aid in the development of treating bone fractures, defects, and diseases. Furthermore, with the induction of a wide variety of TPMS architecture that yields different topologies, the Convolutional Neural Network (CNN) …

Long-Term Simulation Of Stem Cell Mechanobiology, Manoochehr Rabiei

Mechanical and Aerospace Engineering Dissertations - Archive

An accurate representation of cellular mechanobiology necessitates the inclusion of subcellular elements characterized by minute masses and dimensions. These minute objects yield multiscale dynamic models with disproportionate terms, which require inordinate amounts of computational time to simulate. The computational requirements limit the time span of the simulation to time histories shorter than one second, even when employing supercomputers. This work presents a high-speed approach to simulating the mechanobiology of stem cells. The proposed approach separates the computational time from the size, and distribution, of masses of the subcellular elements, enabling the simulation of weeks-long cellular processes within hours on a …

Experimental Study Of Flow Analysis In Single Phase Immersion Cooling Using Tomographic Piv, Vijaya Rama Raju Goriparthi

Mechanical and Aerospace Engineering Theses - Archive

As data centers evolve to support increasing server densities, the inadequacies of traditional air cooling in managing thermal loads have become evident. This is primarily due to an increased demand for powerful CPU and GPU-based platforms that can run Artificial Intelligence (AI) and Machine Learning (ML) workloads amongst others. Consequently, single-phase immersion cooling has gained prominence as an efficient, sustainable alternative, significantly reducing operational costs and energy consumption. This method has shown a remarkable ability to cut cooling energy by up to 90% and overall data center energy use by 50%. The current investigation uses Particle Image Velocimetry (PIV) to …

A Path To Commissioning Of Direct-To-Chip Liquid Cooling For Hyperscale Data Centers Using Experimental And Cfd Techniques, Himanshu Girishchandra Modi

Mechanical and Aerospace Engineering Dissertations - Archive

The escalating demand for computing power in hyperscale data centers necessitates innovative cooling solutions to enhance energy efficiency and ensure sustainable operations. Direct-to-chip liquid cooling has emerged as a promising alternative to traditional air-cooling methods, offering improved thermal management and reduced energy consumption. This dissertation explores a comprehensive approach to commissioning direct-to-chip liquid cooling systems in hyperscale data centers by integrating experimental analyses and Computational Fluid Dynamics (CFD) techniques. The study begins by examining design modifications for air-cooled servers and later analyzes the impact of different parameters for a hybrid-cooled server. It explores the fundamental principles of direct-to-chip liquid cooling …

Kissing Bond Assessment In Adhesive Bonded Carbon Fiber Reinforced Composites Using Dielectric Spectroscopy, Minhazur Rahman

Mechanical and Aerospace Engineering Dissertations - Archive

The widespread use of fiber-reinforced composites in industries such as space, aviation, automobiles, and construction necessitates the formation of robust composite joints between critical structural components. Although adhesive-bonded joints are superior with improved load distribution and reduced weight, they are often overlooked in favor of bolted joints and mechanical fasteners due to the lack of reliable Non-Destructive Evaluation (NDE) techniques for adhesive-bonded composites. The anisotropic nature of the substrate and the intricate interfacial interactions between the adherend and adhesive material present significant challenges for conventional NDE methods. Moreover, weak adhesive bonds can result from uncontrolled manufacturing parameters, such as accidental …

Two-Phase Flow Simulations With Plic-Vof Method And Dynamic Mesh Refinement, Vimalan Adaikalanathan

Mechanical and Aerospace Engineering Dissertations - Archive

Two-phase flows are critical in a variety of engineering applications that span multiple length scales. These applications encompass macroscopic phenomena, such as dam breakage and wave-structure interactions, as well as microscopic events, including droplet impacts and boiling, and mixed-scale issues like spray dynamics. Accurate representation of evolving interfaces is essential for numerical simulations of these problems, and the Volume of Fluid (VOF) method combined with the Piecewise Linear Interface Calculation (PLIC) approach is employed to fulfill this requirement. To tackle the computational challenges associated with high-resolution meshes in deforming two-phase flows, Adaptive Mesh Refinement (AMR) is utilized to enhance mesh …

Experimental Investigations And Optimization Of 3d Printed Cellular Structures For Protection Against Traumatic Brain Injury, Aaron R. Jackson

Mechanical and Aerospace Engineering Dissertations - Archive

Traumatic Brain Injury (TBI) disrupts brain function due to head impacts, blast exposures, and ballistic penetrations. It is a significant cause of mental health issues and disability, particularly among military personnel. Historically, combat helmets were designed primarily to protect against fragments. However, recent data highlights the need for helmets that also protect against blast and blunt impacts. Effective TBI prevention requires helmets that address various energy threats while remaining lightweight. A critical metric in this effort is head acceleration, which is closely linked to injury across different scales of brain damage.

Four lattice structures were 3D printed using Digital ABS …

Synthesis Of Ni-Based Intermetallics By Electrolytic Plasma Processing Of Ti And Ti-Based Alloys, Chuzhong Zhang

Material Science and Engineering Dissertations - Archive

EPP is an innovative surface modification technique that enables the deposition of metal ions from the electrolyte and their integration with substrate atoms to form intermetallic compound surface layers. EPP offers advantages such as high deposition rates, environmental cleanliness, and operational simplicity. In this study, Ni-Ti intermetallic layers were successfully synthesized on a Ti-6Al-4V substrate using EPP. The properties of the resulting Ni-Ti intermetallic layers were characterized using SEM, EDS, XRD, TEM, nanoindentation, and tribology tests.

This work aims to understand the fabrication mechanism and investigate the effects of various processing parameters on the EPP process. Key factors such as …

Introduce Ultrasound Fabry-Pérot Resonator For Attenuation Characterization And Sensitization Detection Of Aluminum-Magnesium Alloys, Songwei Wang

Mechanical and Aerospace Engineering Dissertations - Archive

The Ultrasound Fabry-Pérot Resonator (UFPR) is introduced as a novel technique for non-destructive evaluation and material characterization. By adapting optical Fabry-Pérot Resonator principles to ultrasonic systems, UFPR inherits advantages such as enhanced sensitivity, reduced uncertainty, and the capabilities of frequency-dependent analysis and fringe spectral analysis. This study focuses on UFPR’s application to ultrasonic attenuation characterization and sensitization detection in aluminum-magnesium alloys, which are critical for understanding microstructural changes and improving material performance.

The research was conducted in three systematic steps. First, time-frequency analysis was utilized to examine frequency-dependent attenuation behavior, establishing a foundation for ultrasonic attenuation characterization. Second, longitudinal UFPR …

Mathematical Modeling Of Heat And Mass Transfer In Multilayer Systems, Girish Krishnan

Mechanical and Aerospace Engineering Dissertations - Archive

Multilayer systems are commonly found in a number of engineering devices like Li-ion cells and vertically integrated semiconductor devices. Li-ion cells are widely used for various engineering applications, but they come with a drawback in the form of thermal runaway, and thermal abuse is one of the scenarios that leads to thermal runaway. On the other hand, heterogenous integration in chip and package level architectures is being implemented to keep up with Moore’s law. Modeling of heat and mass transfer in these systems is a topic of interest to improve performance and reliability.

The first segment of this dissertation will …

Development Of A 3d Printed Optimization-Driven Aeroelastically Scaled Wind Tunnel Model For High Aspect Ratio Flying Wings, Mikaela K. Leevy

Mechanical and Aerospace Engineering Theses - Archive

Design optimization coupled with 3D printing and parametric CAD offers a unique approach to investigating flutter phenomena by creating low-cost iterative aeroelastic wind tunnel models. Recently, there is an interest in studying flutter phenomena at low air speeds in flying wing configurations. The X-56 experimental flying wing was designed to investigate flutter phenomena and flutter suppression, which makes the X-56 a logical choice for the full-scale model. The goal of this work is to optimize, physically print, and geometrically characterize a scaled aeroelastic wind tunnel model. The 18% reduced scale X-56 model was optimized by matching the mode shapes to …

Nonlinear Guidance And Control Of Unmanned Aerial Manipulators For Delivering A Payload On A Moving Platform, Ravi Gyawali

Mechanical and Aerospace Engineering Theses - Archive

Unmanned Aerial manipulators (UAMs) are a class of Unmanned Aerial Vehicles (UAVs) equipped with a manipulator. By combining the aerial mobility of a UAV with a manipulator's dexterity, these hybrid systems can perform a wide range of complex tasks while reducing risks and costs. As a result, they are increasingly being utilized for military, industrial, and agricultural applications.

The thesis presents a novel approach for a multi-UAM system to collaboratively deliver a payload on a stationary or maneuvering platform. A sliding-mode-based guidance law, sourced from existing literature, is integrated with a combined control technique for the UAVs and their respective …

Electophorectic Deposition For Novel Nanodecorated Electrodes Towards Thermally Charging Supercapacitor (Tcsc), Ashish Thakur

Mechanical and Aerospace Engineering Theses - Archive

Thermally Self-Charging Supercapacitors (TSCS) are a promising new technology that can harvest waste heat to produce electrical energy. The Soret effect is exploited wherein ion separation due a temperature gradient leads to a potential difference. Here, we use electrophoretic deposition (EPD), a room-temperature, scalable, universal technique, to obtain CNT decorated electrodes for fabrication of such TSCS devices with ionic liquid electrolyte. We further show that precise control over deposition parameters can be used for optimization of TSCS performance metrics. TSCS devices were tested by several characterization standards, indicating the superior performance of nanodecorated electrodes obtained by EPD.

Dynamics Of Separated Flows In Diffusers With Vortex Generators, Sandeep Eldho James

Mechanical and Aerospace Engineering Dissertations - Archive

Flow through curved diffusers is complicated due to the possibility of flow separation and secondary flows. Vortex generators (VGs) are a class of passive flow separation control devices used to improve the flow quality in curved diffusers by suppressing flow separation. However, the literature review demands an in-depth investigation on the physical mechanisms related to flow separation control. Thus, this study aims to improve the understanding of the underlying flow physics associated with VG-induced flow separation control in confined flows. The chosen geometry for this study is a well-documented asymmetric diffuser which exhibits a mild flow separation.

The theoretical formulation …

Generalizable Fugitive Carrier Method For 3d Printing Of Hydrogels, Hakan Arslan

Mechanical and Aerospace Engineering Dissertations - Archive

Hydrogels, with physical characteristics resembling biological soft tissues, hold great potential for bioinspired and biomedical applications. However, using them in additive manufacturing systems has challenges because of their poor mechanical and rheological properties. In response to these challenges, we introduce a fugitive carrier method, a novel and generalizable approach for materials incompatible with pneumatic-based extrusion three-dimensional (3D) printers. Our developed fugitive carrier method allows the 3D printing of a broad spectrum of hydrogel precursors with low viscosity while retaining their inherent properties. This technique has been successfully demonstrated by creating biomimetic structures with anisotropic and programmable systems utilizing temperature-sensitive hydrogel …

Machine Learning-Based Methodology For Multi-Objective And Multi-Design Variable Optimization Of Finned Heat Sinks And Evaluation Of Electrochemical Additive Manufactured Heat Sink Designs For Single-Phase Immersion Cooling, Joseph F. Herring Ii

Mechanical and Aerospace Engineering Dissertations - Archive

Traditional air-cooling along with corresponding heat sinks are beginning to reach performance limits, requiring lower air-supply temperatures and higher air-supply flowrates, in order to meet the rising thermal management requirements of high power-density electronics. A switch from air-cooling to single-phase immersion cooling provides significant thermal performance improvement and reliability benefits. When hardware which is designed for air cooling is implemented within a single-phase immersion cooling regime, optimization of the heat sinks provides additional thermal performance improvements. This work investigates performance of a machine learning (ML) approach to building a predictive model of the multi objective and multi-design variable optimization of …

Generating Blood Analog For Laser Induced Fluorescent Particle Image Velocimetry, Chungyiu Ma, Jared Chong, Hang Yi, Zifeng Yang, Luke Bramlage, Bryan Ludwig

Mechanical and Materials Engineering Faculty Publications

To mimic blood non-Newtonian viscosity features under designated temperatures from 305 to 315 K, transparent blood analogs were generated by the mixture of xanthan gum and deionized water with fluorescent particles for laser induced fluorescent particle image velocimetry.

Rc Baja: Drivetrain And Chassis, Caden Harris

All Undergraduate Projects

The engineers in the CWU Mechanical Engineering Technology program were asked to design and manufacture a remote-controlled Baja car to compete in several different events. The car was required to compete in a drag race, slalom event, and Baja event against other cars created by engineering students. To compete at the highest level, the cars needed to finely balance ruggedness, weight, torque, and top speed.

This report is dedicated to the designing, manufacturing, and testing of the drivetrain and chassis that supported the RC car as it competed in the school-sanctioned competition; a partner was responsible for the steering and …

Rc Baja: Suspension And Steering, Daniel Davis

All Undergraduate Projects

Engineers enrolled in the Mechanical Engineering Technology program at Central Washington University were tasked with developing a vehicle to compete in the ASME Baja competition. The engineers were in teams of two, one focused on suspension and steering and the other focused on drive train and chassis.

To begin the design of the vehicle, engineering analyses were completed on each of the components to comply with the requirements set by the team. After completion of multiple analyses for the components of the vehicle, the dimensions were validated and have been created in a CAD program to allow for virtual assembly …

Rc Baja: Drivetrain & Chassis, Ahmad Adam

All Undergraduate Projects

The project's primary aim is to employ engineering techniques in the design and construction of an RC Baja car, ensuring the chassis and drivetrain are sufficient for participation in the ASME RC Baja competition. The suspension and steering system were entrusted to a teammate to contribute to the project's success.

In approaching this problem, various analyses were conducted during fall quarter, in deciding the design of the RC car. For example, one analysis established the necessary output power to attain a maximum speed of 25 miles per hour within a 15-second timeframe. The analysis employed acceleration and power equations …

Nasa Rocket Payload Airfoil Deceleration, Brycen Geck

All Undergraduate Projects

NASA Student Launch Initiative gave a requirement that a lander must descend to the ground from a height of 400-800 feet with predetermined human survivability without using parachute or streamers. Around sixty colleges were chosen from around the United States to compete in competition. This competition and data taken will help innovate the rocket and lander programs in full scale space exploration in the future.

Design of the payload involved intensive design, testing and aerodynamic analysis. Majority of the manufacturing revolved around 3D printing, aluminum 5051 sheet and carbon fiber vacuum bagging. PLA and PETG was used on components which …

Articulating Balsa Wood Bridge, Nate Harris

All Undergraduate Projects

This report describes the design, construction, and testing of a small-scale articulating balsa wood bridge that allowed passage over normally impassable terrain. The bridge was required to span a 400mm gap, while also articulating the midpoint of the bridge 140mm above its resting position. The bridge also needed to support a 20kg (44 lbs.) point load in the center of the bridge, and the bridge and articulation tower together needed to weigh less than 85 (0.19 lbs.) grams.

To construct the bridge, statics and mechanics of materials was used to design a truss that was calculated to support the load …

Articulating Balsa Wood Bridge, Samuel K. Katsuda

All Undergraduate Projects

The objective of this project was to design, construct and test an articulating balsa wood bridge. It needed to fit certain requirements such as maintaining the bridge structure and articulation structure weight under 85g, being able to articulate 140mm, and be able to withstand a load of 20kg at the middle. The aim was to both create a product, but also give the student a chance to demonstrate their practical knowledge in engineering and going through the processes.

To complete this project as mentioned the student began by creating an initial design and performing a series of analyses on the …

The Tortuga Drivtrain And Chassis Rc Baja, Roberto C. Vieyra Avalos

All Undergraduate Projects

The students in charge of the project, seniors at Central Washington University were tasked with the design and manufacturing of the RC Baja to compete in the Slalom and Sprint event and the Baja event where the maneuverability and acceleration are demonstrated. The project was divided between Roberto, in charge of the drivetrain and chassis and Rogelio, in charge of the steering and suspension. There were also various requirements like velocity and deflection, ensuring the device reaches 30mph and keeping the deflection of components to a minimum and many others which can be seen in section D of the introduction. …

Dueling Robot, Abigail Coy

All Undergraduate Projects

This project was undertaken as a personal challenge to combine a Mechanical Engineering Technology degree and an Electrical Engineering Technology degree into a single final project showing the cumulative knowledge gained. It was determined that a robot to participate in Western Allied Robotics would be designed and manufactured for the 3 lb. weight class.

A two-part power system was designed to provide more power to the weapon arm. This design combined a compressive spring’s kinetic energy with the torque from the electric motor. Research determined all of the purchased components required and analysis were performed to determine the geometry and …

Navigating The Complexities Of Engineering Management: Insights Into Metrics, Measurements, And Pitfalls, Charles Daniels

Engineering Management & Systems Engineering Faculty Publications

In the realm of Engineering Management, the reliance on metrics and measurements stands as a cornerstone for effective decision-making processes. These quantitative tools offer insights into performance dynamics and facilitate informed strategic choices. However, the uncritical application of metrics devoid of profound domain expertise presents significant challenges. This abstract explores the pitfalls inherent in utilizing metrics and measurements within Engineering Management without comprehensive understanding, emphasizing the potential consequences and proposing strategies for navigating this complex terrain.

Design And Analysis Of Electrochemical Additive Manufacturing Based Cold Plates And Heat Sinks For Enhanced Electronics Cooling And Temperature-Dependent Density Characterization Of Phase Change Materials, Jacob Lamotte-Dawaghreh

Mechanical and Aerospace Engineering Dissertations - Archive

The body of work that comprises this dissertation is divided into two main sections. The first section is regarding novel heat sink and cold plate designs that leverage a metal additive manufacturing process called electrochemical additive manufacturing (ECAM) to drive increased thermal performance. The continuous advancements in electronics computational capabilities have resulted in ever-increasing thermal loads at the component and data center server level. These strides within the field are soon to be compounded by the rise of artificial intelligence and machine learning technologies. Traditionally, high performance electronics components have been able to be cooled by forced-air cooling; however, the …

Graphene Reinforced Polymer Composite For Small-Scale Vertical Axis Wind Turbine Rotors, Kunal A. Bachim

Mechanical and Aerospace Engineering Theses - Archive

Polymers have evolved as an indispensable asset in various sectors ranging from packaging and construction to energy and aerospace. However, the accumulation of polymer waste poses a necessity to shift toward sustainable waste management processes. Mechanical recycling is a primary method in establishing a circular economy approach for polymers. However, a fundamental challenge arises in this process: a decrease in the mechanical performance of the recycled product compared to that of its pristine counterpart.

This project addresses the challenge of enhancing the recyclability of polyethylene terephthalate (PET) from discarded polymer material by incorporating graphene nanoparticles into the polymer matrix during …

Development And Application Of Guided Mode Resonance Biosensor Platforms For Highly Sensitive And Real-Time Cell Killing Assays, Seyedmohsen Vaziri

Electrical Engineering Dissertations - Archive

In this work, we developed and investigated the cancer cell killing efficacy of different instances using real-time high-sensitivity measurements facilitated by Guided-Mode Resonance (GMR) sensors. The GMR biosensor technology detects shifts in the spectral peak caused by changes in the refractive index of the surrounding medium, offering a label-free method for monitoring cellular events.

A549 cell line wild type and HER2 knockout (lung cancer cells) were exposed to different concentrations of Triton X-100 and ADC (Herceptin with αHFc-CL-DMDM). The GMR-based cell killing assay demonstrated exceptional sensitivity and specificity, with shifts in wavelength exhibiting a robust correlation with cell viability and …