Mechanical Engineering Commons^™

Sound Propagation In Viscous Flows Using Piezoelectric Sensors And Non-Destructive Propagation Techniques And Its Applications, Ahmed M. Abdulkareem

Theses and Dissertations

Structural non-destructive evaluation techniques are applied to viscous flows to detect fluid property changes. The main operating principle consists of an actuator which provides a stimulus, and a sensor to receive a signal traveling to a fluid domain. The main challenge of the operating principle consists of investigating waves traveling in a viscous flow. Traveling waves utilizing a piezoelectric actuator-sensor pair are modeled and the results are validated experimentally. ANSYS models, coupled with a two-way fluid-solid interaction model, are built to investigate how far a signal travels and what frequency ranges are of interest. The numerical model includes modeling three …

High Tech, High Risk: Tech Ethics Lessons For The Covid-19 Pandemic Response, Emanuel Moss, Jacob Metcalf

Publications and Research

The COVID-19 pandemic has, in a matter of a few short months, drastically reshaped society around the world. Because of the growing perception of machine learning as a technology capable of addressing large problems at scale, machine learning applications have been seen as desirable interventions in mitigating the risks of the pandemic disease. However, machine learning, like many tools of technocratic governance, is deeply implicated in the social production and distribution of risk and the role of machine learning in the production of risk must be considered as engineers and other technologists develop tools for the current crisis. This paper …

Efficient Incorporation Of Fatigue Damage Constraints In Wind Turbine Blade Optimization, Bryce Ingersoll, Andrew Ning

Faculty Publications

Wind turbine design is a challenging multidisciplinary optimization problem, where the aerodynamic shapes, structural member sizing, and material composition must all be determined and optimized. Some previous blade design methods incorporate static loading with an added safety factor to account for dynamic effects. Others incorporate dynamic loading, but in general limit the evaluation to a few design cases. By not fully incorporating the dynamic loading of the wind turbine, the final turbine blade design is either too conservative by overemphasizing the dynamic effects or infeasible by failing to adequately account for these effects. We propose an iterative method that estimates …

Reliability Estimation Of Rotary Lip Seal In Aircraft Utility System Based On Time-Varying Dependence Degradation Model And Its Experimental Validation, Chao Zhang, Rentong Chen, Guanghan Bai, Shaoping Wang, Mileta M. Tomovic

Engineering Technology Faculty Publications

With several attractive properties, rotary lip seals are widely used in aircraft utility system, and their reliability estimation has drawn more and more attention. This work proposes a reliability estimation approach based on time-varying dependence analysis. The dependence between the two performance indicators of rotary lip seals, namely leakage rate and friction torque, is modeled by time-varying copula function with polynomial to denote the time-varying parameters, and an efficient copula selection approach is utilized to select the optimal copula function. Parameter estimation is carried out based on a Bayesian method and the reliability during the whole lifetime is calculated based …

Development Of Bio-Based 2t Engine Oil In Marine Engine Application / Babooraman Shanmuganathan, Babooraman Shanmuganathan

Student Works (2020-2029)

Two-storke enginers are simple and lightweight two-cycle spark ignition engine with no oil sump is needed. The use of bio-based lubricants was analyzed to replace commercial mineral and synthetic-based lubricants. Lubricants were prepared by mixing three components of oil which comprise of base oil, additives, and solvent. In this research, four samples of base oil had been prepared with a different weight ratio of the PFAD-NPGester and Type II mineral. Then each of the simples were added with a similiar weight ratio of additives and solvent. A commercial lubricant was used as areference lubricant to be compared with samples prepared. …

Environmental Advantages In Additive Manufacturing, Analise Walter, Cheryl Marcham

Publications

Additive Manufacturing (AM) is a technology that uses a variety of methods to ultimately apply layers of material and create products (Ford & Despeisse, 2016; Ford, Mortara & Minshall, 2016). Although there has been an expansion in recent technology, AM has been used in manufacturing for a few decades (Ford, Mortara, et al., 2016). Since the late 1980s, AM has grown from simple product designs, with a focus on prototyping and customization, to modern times with billions of dollars in revenue and large-scale production of consumer and industrial products (Cotteleer, 2014). Forecasts showed a near $10 billion market by 2020, …

How Quality Management Has Been Impacted In The Face Of Covid-19, Eldina Siljkovic

Dissertations and Theses @ UNI

The Coronavirus pandemic has impacted many facets of the United States. This study focuses on its magnitude in comparison to prior pandemics such as Anthrax, SARS, and Ebola. In addition to this comparison its impact on Quality Management within the agricultural sector and food supply chain was also assessed. The results of these studies showcase that COVID-19 has grown exponentially in comparison to prior pandemics and will continue to do so as we enter the winter season. Agricultural equipment manufacturing companies saw a drastic decline in quarterly revenues within 2020 in comparison to 2019. Millions in net sales were lost …

Investigation Of Vapor Deposited Conduction Seed Layer For Electrodeposition On Polymers, Olivia Bray

UNF Graduate Theses and Dissertations

The use of three-dimensional printing (3d printing) technologies are becoming increasingly popular in today’s society due to the time and cost advantages associated with these processes. In industries with a high demand for customizable and one-of-a-kind parts at a low volume, these additive manufacturing processes offer a promising solution. Surgical devices are a great example of this demand. Despite the advantages offered by 3d printing, the mechanical integrity of these 3d printed parts are often not comparable to the solid metal parts that have historically been used. In an effort to create a superior part and reach operational requirements, reinforcement …

Carbon-Based Interlayers In Perovskite Solar Cells, Aleksandr P. Litvin, Xiaoyu Zhang, Kevin Berwick, Anatoly V. Fedorov, Weitao Zheng, Alexander V. Baranov

Articles

Perovskites are solution-processed, high-performance semiconductors of interest in low-cost photovoltaics. The interfaces between the perovskite photoactive layers and the top and bottom contacts are crucial for efficient charge transport and minimizing trapping. Control of the collection of charge carriers at these interfaces is decisive to device performance. Here, we review recent progress in the realization of efficient perovskite solar cells using cheap, easily processed, stable, carbon-based interlayers. Interface materials including graphene, carbon nanotubes, fullerenes, graphene quantum dots and carbon dots are introduced and their influence on device performance is discussed.

Measurement Of Current Distribution In The Land Channel Direction Of A Proton Exchange Membrane Fuel Cell, Chinmay Kulkarni

Dissertations, Master's Theses and Master's Reports

A fully functional proton exchange membrane fuel cell with single land channel geometry on the cathode and segmented anode current collector with 9 mm² active area with a 350μm spatial resolution was utilized to measure the local current distribution in the land channel direction. A distinguished printed circuit board approach was used for the data acquisition to adapt to any flow field design.

Performance of this segmented cell was examined at dry, wet and moderate humidity settings to study the water transport phenomenon in the PEMFC. In the dry condition at 60 ͦ C with 0% relative humidity, the …

High-Performance Zero Liquid Discharge (Zld) Treatment Of High-Salinity Brines Using A Multiple-Effect Absorption Distillation Concept, Sunil Pinnu

Dissertations, Master's Theses and Master's Reports

State-of-the-art zero liquid discharge (ZLD) technologies are currently bound with either intensive use of high-grade electrical energy such as mechanical vacuum vapor compressors utilized in brine crystallizers or high capital cost with environmental concerns such as evaporation ponds. The present study aims to address these issues by an innovative desiccant-based ZLD system in which a multiple-effect distillation (MED) unit is uniquely embedded at the heart of an absorption-desorption system. Here, the MED and absorption systems are inherently coupled enabling both heat and mass transfer processes between a high-salinity water and a desiccant solution. The proposed technology employs an absorption-based thermally-driven …

Sensor Fusion And Non-Linear Mpc Controller Development Studies For Intelligent Autonomous Vehicular Systems, Ahammad Basha Dudekula

Dissertations, Master's Theses and Master's Reports

The demand for safety and fuel efficiency on ground vehicles and advancement in embedded systems created the opportunity to develop Autonomous controller. The present thesis work is three fold and it encompasses all elements that are required to prototype the autonomous intelligent system including simulation, state handling and real time implementation. The Autonomous vehicle operation is mainly dependent upon accurate state estimation and thus a major concern of implementing the autonomous navigation is obtaining robust and accurate data from sensors. This is especially true, in case of Inertial Measurement Unit (IMU) sensor data. The IMU consists of a 3-axis gyro, …

Optimal Mission Planning Of Autonomous Mobile Agents For Applications In Microgrids, Sensor Networks, And Military Reconnaissance, Casey D. Majhor

Dissertations, Master's Theses and Master's Reports

As technology advances, the use of collaborative autonomous mobile systems for various applications will become evermore prevalent. One interesting application of these multi-agent systems is for autonomous mobile microgrids. These systems will play an increasingly important role in applications such as military special operations for mobile ad-hoc power infrastructures and for intelligence, surveillance, and reconnaissance missions. In performing these operations with these autonomous energy assets, there is a crucial need to optimize their functionality according to their specific application and mission. Challenges arise in determining mission characteristics such as how each resource should operate, when, where, and for how long. …

Identification Of Heat Release Shapes And Combustion Control Of An Ltc Engine, Radhika Sitaraman

Dissertations, Master's Theses and Master's Reports

Low Temperature Combustion (LTC) regimes have gained attention in internal combustion engines since they deliver low nitrogen oxides (NOx) and soot emissions with higher thermal efficiency and better combustion efficiency, compared to conventional combustion regimes. However, the operating region of these high-efficiency combustion regimes is limited as it is prone to knocking and high in-cylinder pressure rise rate outside the engine safe zone. By allowing multi-regime operation, high-efficiency region of the engine is extended. To control these complex engines, understanding and identification of heat release rate shapes is essential. Experimental data collected from a 2 liter 4 cylinder LTC engine …

Efficient Enhancement Of Micro-Nucleation Rates In Flow-Boiling - By Concurrent Micro-Structuring Of The Boiling-Surface And Its Judicious Energization By Piezoelectric-Transducer Induced Acoustic Vibrations., Atharva Rahane

Dissertations, Master's Theses and Master's Reports

The report describes the science and technology backgrounds and uses for the technology breakthrough reported for enhanced flow-boiling based cooling of high-power density electronics (chips, memory etc.). A controlled but explosive growth in micro-scale nucleation rates during flow-boiling of HFE-7100 (electronics and environment friendly liquid from 3M, Inc) is enabled by the uses of inexpensive meshed-copper for micro-structuring of the boiling surface and a pair of Piezoelectric-transducers for active imposition of suitable acoustic vibrations. The pair of piezo transducers mounted just outside the mini-channel impose “in plane” acoustic vibrations of controllable amplitudes and frequencies, and they are used to induce …

Heterogeneous Uncertainty Quantification For Reliability-Based Design Optimization, Mingyang Li

Dissertations, Master's Theses and Master's Reports

Uncertainty is inherent to real-world engineering systems, and reliability analysis aims at quantitatively measuring the probability that engineering systems successfully perform the intended functionalities under various sources of uncertainties. In this dissertation, heterogeneous uncertainties including input variation, data uncertainty, simulation model uncertainty, and time-dependent uncertainty have been taken into account in reliability analysis and reliability-based design optimization (RBDO). The input variation inherently exists in practical engineering system and can be characterized by statistical modeling methods. Data uncertainty occurs when surrogate models are constructed to replace the simulations or experiments based on a set of training data, while simulation model uncertainty …

Using Transfer Path Analysis And Frequency Based Substructuring To Develop A Robust Vibration Laboratory Dynamic Test Fixture Design Process, Cora Taylor

Dissertations, Master's Theses and Master's Reports

The objective of this research is to determine a robust method for designing shock and vibration laboratory test fixtures that accurately reproduce the field environment for the component of interest. The methods presented in this research examine the boundary conditions presented unto the component of interest through transfer path analysis with the intent of reproducing the next-structure attachment impedance with a laboratory test fixture of one and two attachments. The first method includes only using the next-structure relative motion and stiffness to design a test fixture, while the second method uses an optimization algorithm to develop a lumped parameter model …

Experimental Evaluation Of An Rwd Vehicle With Parameter Extraction For Analytical Modeling And Evaluation, Jon Furlich

Dissertations, Master's Theses and Master's Reports

This study was conducted to perform experimental vibration testing on a light duty rear wheel drive vehicle. The vehicle is known to have excessive longitudinal acceleration response perceived after step changes in the driver torque command. The excessive response includes shuffle and clunk transients. Experimental testing was performed to understand the coupling between driver torque commands and peak shuffle oscillations. Data was also targeted to understand the coupling between driveline torsional oscillations and longitudinal vehicle vibrations. This data was also used to establish vehicle parameters for use in an analytical CAE model of the driveline and coupling. Driver applied tip-in …