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 …

Numerical Study Of Flow Characteristics Around A 30° Yawed Circular Cylinder At R E = 10 4, Ran Wang, Shaohong Cheng, David S.K. Ting

Mechanical, Automotive & Materials Engineering Publications

Unstable motions of bridge stay cables have been observed on site and in wind tunnel tests when a cable is yawed at certain orientations to wind. To uncover the underlying mechanisms, flow around a circular cylinder at a yaw angle of 30° has been numerically analyzed in the current study using delayed detached eddy simulation (DDES) at R e = 10 4 . A comparison with the reference normal flow case indicates the presence of a more coherent span-wise flow structure when the cylinder is yawed at 30°. The application of proper orthogonal decomposition further reveals that at this orientation, …

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 …

Investigation Of Solar Assisted Water Heating System Integrated With Pcm Storage Tank, Sohrab Saadat Pour

Major Papers

This study discusses the importance of integrating renewable energy sources, particularly Solar Water Heating Systems (SWHSs) with Thermal Energy Storage (TES) technology, to address the growing energy consumption in residential buildings, aligning with the United Nations' Sustainable Development 2030 agenda. The combination of SWHSs and TES helps reduce building energy consumption by storing excess solar energy, which can be used for Domestic Hot Water (DHW) needs during peak periods and nighttime. The study proposes a dynamic model using TRNSYS software to simulate a SWHS over a 30-hour period in a residential apartment. Additionally, a novel MATLAB component simulates an encapsulated …

Studying The Influential Parameters Of An Office Building’S Energy Consumption In North America, Naveen Raghava Krishnan Bhoopal

Major Papers

The study of building energy consumption has gained immense significance in recent times due to the burgeoning global population and the rapid depletion of energy resources. The present research focuses on analyzing individual parameters that impact building energy usage and devising methods and strategies to reduce energy consumption. An existing office building in Philadelphia was chosen as a reference for simulation in TRNSYS. The factors that affect the building, such as ambient temperature, solar radiation, building envelope, wind speed, and internal gains, were studied and defined according to the existing building standards. Predictive modeling is performed with these inputs for …

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 …

Thermal Modelling Of A Passive Style Net-Zero Greenhouse In Alberta: The Effect Of Ground Parameters And The Solar To Air Fraction, Oselen J. Imafidon, David S.K. Ting, Rupp Carriveau

Mechanical, Automotive & Materials Engineering Publications

Agricultural greenhouses can provide a suitable microclimate for crops to thrive under extreme weather conditions. The operations of these greenhouses are expensive due to the energy requirement of the active thermal conditioning systems required to maintain the growing environment for crop production. Engineering of these greenhouses to utilize clean renewable energy sources is critical and necessary to mitigate their carbon footprint, paving the way to a more sustainable agricultural industry. This paper presents numerical modelling of a net-zero passive solar greenhouse in Alberta, Canada with winter temperatures below freezing. The indoor microclimate of the greenhouse is modelled using the detailed …

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 …

Development Of Thermally Stable And Environmentally Robust Microelectromechanical Systems (Mems) Based Accelerometers, Hasnet Eftakher Uddin Ahmed

Electronic Theses and Dissertations

Microelectromechanical systems (MEMS) inertial sensors are widely used in many motion sensing applications including acceleration and orientation. Many of these sensors employ a small resonating mass as the main sensing element. Various applications of MEMS resonating sensors require the sensor to endure temperature and dynamic environmental parameters variation, which can cause their resonance performance to degrade. This research focuses on developing understanding of improving thermal stability of MEMS resonating inertial sensor performance improvement and its characterization in dynamic environments. Thermal stability of the resonating structure can be achieved using doping-based passive compensation methods. Analytical and numerical modeling techniques are presented …

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 …

Improvement To An Existing Multi-Level Capacitated Lot Sizing Problem Considering Setup Carryover, Backlogging, And Emission Control, Rifat Bin Hasan, Hany Osman, Ahmed A. Azab Ismail, Fazle Baki

Mechanical, Automotive & Materials Engineering Publications

This paper presents a multi-level, multi-item, multi-period capacitated lot-sizing problem. The lot-sizing problem studies can obtain production quantities, setup decisions and inventory levels in each period fulfilling the demand requirements with limited capacity resources, considering the Bill of Material (BOM) structure while simultaneously minimizing the production, inventory, and machine setup costs. The paper proposes an exact solution to Chowdhury et al. (2018)'s[1] developed model, which considers the backlogging cost, setup carryover & greenhouse gas emission control to its model complexity. The problem contemplates the Dantzig-Wolfe (D.W.) decomposition to decompose the multi-level capacitated problem into a single-item uncapacitated lot-sizing sub-problem. …

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 …

Machine Learning Approach To Investigate Ev Battery Characteristics, Shayan Falahatdoost

Major Papers

The main factor influencing an electric vehicle’s range is its battery. Battery electric vehicles experience driving range reduction in low temperatures. This range reduction results from the heating demand for the cabin and recuperation limits by the braking system. Due to the lack of an internal combustion engine-style heat source, electric vehicles' heating system demands a significant amount of energy. This energy is supplied by the battery and results in driving range reduction. Moreover, Due to the battery's low temperature in cold weather, the charging process through recuperation is limited. This limitation of recuperation is caused by the low reaction …

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 …

Optimal Kanban Number: An Integrated Lean And Simulation Modelling Approach, Angassu Girma Mullisa, Walid Abdul-Kader

Mechanical, Automotive & Materials Engineering Publications

Kanban is credited as a major means to controlling the inventory within a manufacturing system. Determining the optimum number of Kanban is of great interest for manufacturing industries. To fulfill this aim, an integrated modelling approach using discrete-event simulation technique and Kanban Lean tool is developed for a pull system ensuring an optimum Kanban number. This research has developed a base-case simulation model which was statistically validated using ANOVA. Initial Kanban number obtained from the mathematical model of Toyota motor company is used to obtain initial results. A Kanban integrated simulation model is developed that employed the idea of pull …

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 …

A New Loss Generation Body Force Model For Fan/Compressor Blade Rows: Application To Uniform And Non-Uniform Inflow In Rotor 67, Syamak Pazireh, J. J. Defoe

Mechanical, Automotive & Materials Engineering Publications

Despite advances in computational power, the cost of time-accurate flows in axial compressor and fan stages with spatially non-uniform inflow is still too high for design-stage use in industry. Body force modeling reduces the computation time to practical levels, mainly by reducing the problem to a steady one. These computations are important to determine efficiency penalties associated with non-uniform inflows. Previous studies of body force methods have, in most cases, relied on computations with the presence of the blades to calibrate loss models. In some recent studies, uncalibrated models have been used, but such models can drop off in accuracy …

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 …

Design And Development Of A 3d-Printed Microfluidic Lab-On-A-Chip For Particle Manipulation, Hualong Wang

Electronic Theses and Dissertations

In past decades, microfluidic devices have been widely used in chemical and biological fields. On the microscale, the fluid will be laminar fluid due to the low Reynolds number, which makes it challenging to cause mixing in the microfluidic device. Thus, mixing performance is an extremely significant property for microfluidic devices. In this thesis, a 3D-printed electrophoresis-based particle manipulator has been developed to increase particle-mixing performance. In this thesis to enhance mixing a new design is proposed utilizing a 3D rotating electrical field to enhance mixing. In order to manipulate the particle, four electrodes will be placed in different directions, …