Digital Commons Network^™

Dynamic Material Characterization Of Polymeric Foam By Means Of Experimental, Analytical, Phenomenological And Numerical Methods, Foad Rahimidehgolan

Electronic Theses and Dissertations

The main objective of this study was to advance the experimental, numerical, phenomenological and analytical methods of assessing the dynamic compressive response of polymeric foams, especially at an intermediate strain rate range of 50 s-1 to 600 s-1. Different experimental apparatuses and techniques, including the universal compression/tension testing machine (strain rates up to 0.5 s-1), custom-build droptower (a strain rate range of 50 s-1 to 200 s-1) and pneumatic testing apparatus (a strain rate range of 200 s-1 to 600 s-1) were utilized in the macro-mechanical characterization. The microstructure of the investigated polymeric foams was studied by means of Scanning …

Anisotropic Mechanical Material Investigation On Moisture And Strain Rate Sensitivity Of Direct Compounded Compression Moulded Glass/Pa6 Lfts, Pouya Mohammadkhani

Electronic Theses and Dissertations

In this study the tensile properties at different loading rates as well as shear properties of a direct-compounded compression-moulded Polyamide6 (PA6)/glass long fibre thermoplastic (LFT-D) material with a fibre weight content of 30% were investigated. The effects of moisture on the anisotropic mechanical and material properties of Glass/PA6 LFT materials were examined by testing at four different material directions of 0°, +45°, ˗45°, and 90°. In order to study the effect of tensile loading rate on this material, different nominal strain rates ranging from 0.0001 1/s to 150 1/s were examined. Under quasi-static loading, at a 2% moisture content, the …

Residual Stress In Metal Additive Manufacturing Of Thin-Walled Components: Investigation And Development Of Prediction Models With Respect To Path Planning, Bita Mohajernia

Electronic Theses and Dissertations

This dissertation focuses on the investigation of residual stress in metal additive manufacturing of thin-walled components. Residual stress is a critical issue in additive manufacturing processes as it can lead to structural deformations, reduced mechanical properties, and potential failure of the manufactured parts. The objective of this research is to develop a fast and accurate prediction model for residual stress using numerical and machine learning techniques, with a specific focus on path planning. To achieve the research objectives, the dissertation employs numerical simulations to understand the underlying physics and mechanics of residual stress formation in the additive manufacturing process. These …

Variability Of Noise Exposure Forecast Outputs Due To The Selection Of Input Parameters, Junxian Zhao

Electronic Theses and Dissertations

The growth of civil aviation and the resulting aircraft noise exposure and noise annoyance have become a serious environmental issue for residents living around airports. Land use planning and management is one method to mitigate noise and annoyance. It is one of four components of the Balanced Approach to Aircraft Noise Management adopted by International Civil Aviation Organization (ICAO). Effective land use and planning tries to remove conflicts between noise and residential communities by keeping noise sensitive functions away from levels of predicted high noise exposure. Authorities typically use noise contours to determine noise exposure around airports. Noise thresholds are …

Prediction And Management Of Aircraft Noise Annoyance Around Canadian Airports, Julia Georgieva Jovanovic

Electronic Theses and Dissertations

Noise pollution is a serious environmental problem affecting millions of people world-wide. Aircraft are one source of transportation noise that impacts residents in communities surrounding airports and flight paths. Noise is the biggest nuisance of airport operations and has resulted in complaints, protests, and even legal action. The burden of noise is likely to increase in the coming decades as quieter aircraft technologies lag traffic growth projections, and rapid urbanization narrows the buffer between airports and residential areas. Numerous physical and psychological effects of aircraft noise exposure have been studied, the most common of which is annoyance. Noise annoyance has …

Microstructure, Mechanical Properties And Electrical Conductivities Of As-Cast Al-0.3mn Alloy, Wutian Shen

Electronic Theses and Dissertations

Al-0.3Mn was prepared by permanent steel mold casting (PMSC) with three different section thicknesses of 6, 10, 20 mm, and also by squeeze casting (SC) with a cross-sectional thickness of 20 mm under an applied pressure of 90 MPa. The first group of samples was employed to investigate the difference in mechanical and electrical properties between the PSMC Al-0.3Mn Alloy and high-purity (HP) Al (99.9%). The results of tensile testing indicated that the ultimate tensile strength (UTS), yield strength (YS) of the cast HP Al significantly increased to 72.3 and 20.4 MPa from 59.2 and 14.0 MPa. However, the elongation …

Reducing Energy Usage For Residential Furnace Blowers: Blade Re-Design And Assessment Of The Impact Of Flow Non-Uniformity Elimination, Mohammad Mirmohammadi

Electronic Theses and Dissertations

Residential furnace blowers are widely used in North America, but they often are designed to be low-cost rather than highly efficient. In this study, analysis of the literature yields an estimated adiabatic efficiency for typical furnace blowers of approximately 48%. The geometry of a typical furnace suggests much of the cause of this low efficiency is due to poor flow uniformity entering the blower. While the specific diameter and specific speed of the blower lie far from the Cordier diagram locus, these parameters cannot be dramatically changed due to space constraints. Thus, this study aims to quantify the efficiency gain …

Application Of Equilibrium-Based Pah Adsorption To Modelling Graphene Synthesis In A Microwave-Assisted Plasma Reactor, Jiahai Fan

Electronic Theses and Dissertations

Graphene is a new material with potential to significantly impact many applications due to its unique physical and chemical properties. However, the commercialization of graphene is impeded by issues in graphene mass production. Recently, a potential production method that uses a microwave-assisted plasma reactor to produce graphene has been developed, and this method might make mass production of graphene possible. To aid in development of this new method, a novel computational model to simulate graphene synthesis in this system was developed. While it was the first attempt at modelling graphene synthesis in such a system, the model required improvement due …

The Importance Of Accurately Predicting Corner Separations In Fan Stall Point Identification With Steady Rans: Computations With The Helicity-Corrected Spalart-Allmaras Turbulence Model, Zhifan Yu

Electronic Theses and Dissertations

This thesis applies a modified Spalart-Allmaras (SA) turbulence model, the helicity-corrected Spalart-Allmaras (HCSA) model, in incompressible steady Reynolds-averaged Navier-Stokes (RANS) computations to reduce the numerical simulation run time for fan stall inception prediction. Computations are carried out using the OpenFOAM package. This manuscript-style thesis contains two main chapters, each stemming from conference papers. First, the HCSA turbulence model is applied to a low-speed axial fan, known as the boundary layer ingestion (BLI) fan, for fan stall behavior simulation. Both RANS and unsteady RANS (URANS) with the HCSA model and RANS with the original SA model are performed, with all results …

Model-Guided Extremum Seeking Control For Mechanical Ventilators, Ryan Keith Wardell

Electronic Theses and Dissertations

Mechanical ventilators are an important lifesaving medical device and because of the COVID-19 pandemic, they were in a massive demand for them to help the patients most severely affected by the disease. A large number of open-source hardware ventilator projects were established during the pandemic, most of which did not provide sufficient information on the design of their control systems. In this thesis, a model-guided extremum seeking control scheme is proposed for use on a open-source hardware ventilator design. The performance of the control scheme is intended to not be significantly affected by changes to the patient, nor to variations …

Superhydrophobic And Oleophobic Surfaces. Synthesis And Applications, Zirui Liu

Electronic Theses and Dissertations

Surface patterning is an overwhelming approach to mechanically modifying metal surfaces and improving their tribological properties, such as repellency, lower friction, and more excellent corrosion resistance. Patterned surfaces can be applied to various industrial uses, such as cutting tools, submarines, and self-cleaning surfaces. In this paper, the novel nature-inspired flat-top-pillar "double-undercut" designs were proposed to achieve an apparent angle that satisfies super-hydrophobicity and endure higher pressure on which external forces are exerted. The main objective is to enlarge the change in Gibbs free energy for the system to exhibit a heterogeneous wetting to a homogeneous one by excavation on the …

Thermal Analysis Based Design Of Hollow Shaft For Improved Cooling Of Induction Motors, Isabelle Dinh

Electronic Theses and Dissertations

This thesis investigates methods of implanting a forced liquid convection heat recovery system within an induction motor’s shaft to cool the rotor.

The objective is to design a hollow shaft that can meet the target goals of keeping the components under an average temperature of 100℃ under different motor power conditions. Three hollow shaft design cases were studied at steady state conditions to evaluate their heat transfer performance and surface temperature to meet the goals of the study. This includes the design of a counterflow, counterflow with fins, and duct design.

It is found that third design is able to …

Fault Diagnosis Of Lubrication Decay In Reaction Wheels Using Temperature Estimation And Forecasting Via Enhanced Adaptive Particle Filter, Madhi Aldadi

Electronic Theses and Dissertations

Reaction wheel (RW), the most common Attitude Control Systems (ACS) in satellites, are highly prone to failure. A satellite needs to be oriented in a particular direction to maneuver and accomplish its mission goals; losing the RW can lead to a complete or partial mission failure. Therefore, estimating the remaining useful life (RUL) in long and short spans can be extremely valuable. The short-period prediction allows the satellite's operator to manage and prioritize mission tasks based on the RUL and increases the chances of a total mission failure becoming a partial one. Studies show that lack of proper bearing lubrication …

Experimental Improvements To A Constant Volume Combustion Chamber For Fuel Spray And Ignition Studies, Binghao Cong

Electronic Theses and Dissertations

The primary objective of this thesis is to improve optical setups of a constant volume combustion chamber to better understand the vaporization and spray characteristics of various fuels. The schlieren imaging technique is utilized to visualize phenomena that are challenging to observe directly. In this thesis, the schlieren imaging is used to observe the spray and ignition characteristics of DME and diesel fuels under high injection pressure.

First, various optical techniques are discussed and compared under the same test condition including schlieren, shadowgraph, and direct imaging. The advantages for these techniques are presented and the most appropriate technique for different …

Enhancing Thermoelectric Generator Performance, Xi William Wang

Electronic Theses and Dissertations

Waste heat recovery plays an important role for alleviating the energy crisis and mitigating climate change. The thermoelectrical generator (TEG), a solid energy convertor, is a promising technology. However, the performance of a TEG is sensitive to its geometric structure and working conditions. An improved geometric structure and matching to the working conditions can make a TEG fully utilize its thermoelectrical conversion potential.

The TEG optimization is a kind of combinatorial problem. An effective algorithm is needed to optimize a TEG’s performance. The particle swarm optimization (PSO) algorithm is introduced in this study to optimize a TEG’s output power, efficiency, …

High Temperature Lubricated Wear Of Sand Cast And Die Cast Al Alloys For Continuously Variable Transmission (Cvt) And Other Applications, Xi Zhang

Electronic Theses and Dissertations

Light weight alloys like aluminum-silicon (Al-Si) alloys and magnesium alloys are widely utilized in the automobile industry. They have several favorable properties such as high wear resistance and good corrosion resistance at a wide range of temperatures. However, their wear-resistance under harsh operating conditions such as oxidation, creep and thermal fatigue still needs to be improved. In this work, the tribological behaviour of Al-Si alloys die cast A380, die cast ADC10, sand cast A356-T6, die cast B390, and magnesium alloy AE44 were investigated using a block-on-ring tribometer at 93 °C and 130 °C sliding temperatures and fixed sliding speed of …

Analysis Guidelines And Functionalities Of The Catia Native Fea Solver For Composite Materials, Mohamed Edrisy

Electronic Theses and Dissertations

The emergence of commercial FEA solvers was a significant breakthrough that boosted the accuracy and complexity of engineering design. While composite materials are special materials, their mechanical properties can be custom made by considering the needs and requirements of the design problem. Given the rapidly expanding global consumption of composite materials, access to FEA solvers capable of assigning these materials is an absolute requirement.The CATIA software is a platform for designing, analyzing, and manufacturing of parts. However, there is no meaningful documentation in the public domain exploring the finite element functionalities of CATIA software for composite materials. Isotropic materials are …

Transient Experimental Study Of A Latent Heat Thermal Energy Storage In A Phase Change Material-Air-Liquid Heat Exchanger, Serena Askar

Electronic Theses and Dissertations

The increase in energy consumption and the demand for effective thermal management systems necessitate the search for enhanced heat exchangers with high thermal performance, lower weight, and compact sizes. Crossflow heat exchangers are a key component in the thermal management system of many industries such as HVAC, automotive, etc. Generally, heat exchangers are characterized based on their steady state operating conditions. However, a transient analysis helps predict the behavior of heat exchangers when they experience variations in their operational conditions in terms of fluid flow rate and temperature.

Thermal management and thermal comfort can be achieved through active and passive …

Characterization Of A Three-Way Catalyst For High Efficiency Spark Ignition Engines, Cavin Hesketh

Electronic Theses and Dissertations

The push for environmental protection and sustainability has led to strict emission regulations for automotive manufacturers as evident in EURO VII and 2026 EPA requirements set to take effect in the coming years. The modern gasoline spark ignition (SI) engine typically employs various in-cylinder emission reduction techniques along with an exhaust after-treatment system to comply with emission standards. The three-way catalyst (TWC) is wholly responsible for removing the engine-out emissions including hydrocarbons (HC), carbon monoxide (CO) and nitrogen oxides (NOx). The main objective of this thesis is to investigate the impact of extensive exhaust gas recirculation (EGR) on …

Development Of Predictive Ballistic Models For Hypervelocity Impact On Sandwich Panel Satellite Structures, Riley Carriere

Electronic Theses and Dissertations

Sandwich panels are widely used in the design of uninhabited satellites and, in addition to having a structural function can often serve as shielding, protecting the satellites’ equipment from hypervelocity impacts (HVI) of orbital debris, and micrometeoroids. This thesis aims to provide: a comprehensive review of HVI experimental studies for honeycomb- and open-cell foam-cores; an examination of available predictive models used to assess the panels’ ballistic limits; as well as signify the influence of honeycomb-core parameters, such as cell size and foil thickness, as well as core material, on the ballistic performance of honeycomb-core sandwich panels (HCSP) when subject to …

Experimental Setup Of A Rapid Compression Machine For Spark Ignition Studies, Daniel Llaguno

Electronic Theses and Dissertations

The main objective of this thesis is to document the design and development of a rapid compression machine (RCM). A series of tests were performed to verify the operation of the system using the compression of air. Finally, an experiment was conducted to validate the auto-ignition temperature of DME under HCCI mode. Based on the first version of the RCM, improvements were made to speed up the compression process, and to create the conditions required for the auto-ignition of a DME-air mixture. The inlet diameter of the pneumatic actuation cylinder was increased to reduce the choking effect of the air …

Heat Transfer And Fluid Flow Analysis Of Molten Salt Heat Exchanger In A Novel Thermolysis Reactor Design For The Thermochemical Cu-Cl Cycle For Hydrogen Production, Ehsan Armoudli

Electronic Theses and Dissertations

Among the new methods for producing clean hydrogen, the thermochemical copper-chlorine (CuCl) cycle is one of the most promising due to the relatively high exergy and energy efficiencies and lower temperature requirements. However, there are challenges with regard to the thermal performance of the components of the cycle. This study focuses on designing a new heat exchanger for the thermolysis reactor, which is found to be the most critical component because of having the highest operating temperature, highest exergy destruction, and material handling difficulties. The objective is to provide the required operating temperature, of 430 to 530 °C, for the …

Design And Analysis Of Soft Actuator With Enhanced Stiffness With Granular Jamming, Abbishek Manoj Patel

Electronic Theses and Dissertations

The field of soft robotics has been increasing popularity and importance in last decade with its groundbreaking applications in the field of delicate food handling industry and rehabilitation of limbs and fingers of stroke affected patients. The area of soft robotics seeks to improve robot safety, allowing them to function in circumstances where standard robots cannot.

This research is focused on pneumatically actuated soft robots as they are efficient, easily controlled, affordable, and well researched. These robots consist of one or more soft actuators, made of silicone elastomers with low material hardness. Low hardness silicone actuators are structurally weak and …

Mechanical Characterization Of Direct/In-Line Compounded, Compression Molded Polyamide / Carbon Fibre Long Fibre Thermoplastic, Matthew Bondy

Electronic Theses and Dissertations

Direct compounded compression molded carbon fibre long fibre thermoplastic (LFT-D) combines the high strength and stiffness of carbon fibre with a mass production manufacturing process intended to maximize fibre length. However, this process is more commonly used in industry with glass fibre. Extensive characterization of mechanical properties, spanning fundamental tensile tests to impact characterization of standard specimens and a complex automotive component, was completed to understand the strengths and deficiencies of this novel material formulation for engineering applications: fundamental uniaxial tension (quasi-static and intermediate strain rate) and three-point bending tests, tensile stress-life fatigue characterization, ISO 6603-2 instrumented impact of standard …

Effects On Vehicle Ride Comfort Of An Adaptive Suspension System Using Neural Networks, Sylvia Yin Zhixian

Electronic Theses and Dissertations

Suspension systems in the auto industry have always been a topic of interest, as they relate to so many aspects of vehicles. Various types of suspension are commonly used now, such as passive suspensions, semi-active suspensions and active suspensions. However, the current technology mainly focuses on the change of damping ratio. The aim of this thesis is to consider both spring and damper properties for suspensions of an off-road vehicle. In order to do this, a 10-degree of freedom model was built using the EoM software in Julia. The output state space matrices from EoM were used as an input …

Analysis Of Combustion In Plasma Electrolytic Oxidation (Peo) Coatings Of The Piston Surface In Spark Ignition Engines, Brendon Bain

Electronic Theses and Dissertations

With the global effort to “green” the transportation industry, the internal combustion engine (ICE) is required to reduce its carbon footprint and can do so by increasing efficiency. Plasma Electrolytic Oxidation (PEO) coatings confer properties of high wear and corrosion resistance, high hardness, excellent adhesion and a superior thermal barrier to their substrate, suggesting that coating of ICE components has the potential to greatly improve the combustion efficiency. The primary objective of this thesis is to analyze the effects of PEO coating on the surface of pistons in a spark ignition ICE, with the goal of increasing efficiency, to address …

Development Of A Model For Graphene Synthesis In Microwave Plasma-Assisted Reactors, Caleb Prindler

Electronic Theses and Dissertations

Graphene is a novel nanomaterial capable of revolutionizing technology in many sectors but is difficult to produce on a useful scale. To improve our understanding of graphene formation, a computational model has been developed to simulate graphene synthesis in a scalable microwave plasma reactor. Unlike earlier graphene growth models, this one uses a sectional method to solve the population balance model. A sensitivity analysis was performed to assess the impact of the individual process rates. The rates were adjusted by multiplying and dividing the base rates by a factor of 2. The process rates that were adjusted in this way …

Bake-Hardening Of Aluminum Alloys For Automotive Applications: Influence Of Temperature, Time And Pre-Strain Parameters, Giorgio Rolle

Electronic Theses and Dissertations

An experimental evaluation of the effect of bake hardening on aluminum alloys for automotive lightweight applications is developed through tensile tests and dent tests. All the alloys belong to the 6xxx series and include high formability alloys, improved hemming types and improved bake response alloys. An experimental matrix which contains different time-temperature baking conditions is built, and two pre-strain conditions are considered: no pre-strain and 2% pre-strain. A suitable testing phase is designed to be as much representative as possible of the actual manufacturing process of an automotive panel. After a data analysis phase performed by means of MATLAB software, …

Numerical Performance Prediction Of A Composite Automotive Suspension Lower Arm, Zhe Ma

Electronic Theses and Dissertations

Using the lower arm from the front suspension of a typical passenger sedan as an example, this research explores the possibility of replacing automotive load bearing metal components with fibre reinforced plastic equivalents that could be manufactured using the injection moulding process.

To begin the study, the vehicle motion was modelled using a high fidelity multibody dynamics motion solver, under multiple different driving scenarios and road roughness levels. The time history of the suspension loads were recorded, and maximum load cases were identified and classified.

The injection moulding process was modelled using a sophisticated in-mould flow simulation software. The resulting …

A Preliminary Study Of Electrode Geometry Impact On Spark Discharge Processes, Hongyang Shangguan

Electronic Theses and Dissertations

The ever-growing demands to meet the exhaust emission regulations and fuel economy requirements have driven the development of modern spark ignition (SI) engines towards lean/diluted combustion strategies and engine downsizing. Currently, the transistor coil ignition (TCI) system is still the dominant ignition system applied in SI engines. This work investigates the effects of electrode diameters on the spark discharge characteristics.

In this study, different electrode diameters (0.2 mm, 0.7 mm, 1.5 mm, and 3.5mm) are used. The electrical waveforms of the discharge process are recorded, including the breakdown voltage, the glow voltage, and the secondary current. Results show that the …