Mechanical Engineering Commons^™

Finite Element Analysis Of Thermal-Mechanical Instabilities In Nonmetallic Friction Composite Material, Joseph-Shaahu Shaahu

Electronic Theses and Dissertations

Thermal-mechanical instability (TMI) has been a research topic of interest as it focuses a lot on transportation systems. Thermal-mechanical instability was first noticed in railway and experimentally studied with a pin-to-pin or pin-to-surface setup of sliding contact. The topic has been extended into brakes and clutches which are two of the most common sliding systems most susceptible to thermal buckling and thermoelastic instability (TEI), where thermal buckling and thermoelastic instability are two sub-categories of thermal-mechanical instability. Thermal-mechanical instability is an ongoing research to better understand the phenomenon and the limits at which such instability occurs. This work delved into the …

Enhancing Traffic Safety In Unpredicted Environments With Integration Of Adas Features With Sensor Fusion In Intelligent Electric Vehicle Platform With Implementation Of Environmental Mapping Technology, David S. Obando Ortegon

Electronic Theses and Dissertations

A major objective on society is to reduce the number of accidents and fatalities on the road for drivers, and pedestrians. Therefore, the automotive engineering field is working on this problem through the development and integration of safety technologies such as advanced driving assistance systems. For this reason, this work was intended to develop and evaluate the performance of different ADAS features and IV technologies under unexpected scenarios. This by the development of safety algorithms applied to the intelligent electric vehicle designed and built in this work, through the use of ADAS sensors based on sensor fusion. Evaluation of AEB, …

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 …

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 …

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, …

Redesign And Benchmarking Of Electric Vehicle Batteries For Demanufacturing For Secondary Life Applications In The Circular Economy, Abhay Singh Rathaur

Electronic Theses and Dissertations

As per the latest records, the transportation sector is the second largest in energy consumption and plays a major role in air pollution and co2 emission. One solution to curb this pollution and release of hazardous gases is li-ion batteries by electrifying the vehicles. However, these batteries have one factor over here: once EV batteries reach 70-80% charge holding capacity, they are not good enough for traction in the vehicle. Therefore, replacing these batteries with a new ones is necessary. However, these discarded batteries have enough charge holding capacity, which can be used in secondary applications called second- …

Analysis Of Bio-Alcohols With Mie-Scattering And Ltc For Lowered Emissions In Pcci, Cesar E. Carapia

Electronic Theses and Dissertations

An investigation was conducted on the optimal engine parameters for facilitating lower NOX and soot emissions of PCCI combustion with either ethanol or n-butanol. The PFI fuels selected were tested at loads of 3, 4, and 5 Bar IMEP for a total of 28 total combustion tests with variations made to the EGR% and boost pressure for each test in order to find the optimal emissions strategy. A Mie-scattering spray fuel analysis was also conducted on the three fuels to gain insight on their influence on combustion/emissions characteristics. It was found that ethanol had a greater average Sauter Mean Diameter …

Quantification Of Velocity At The Sparkplug In A Lab Scale Combustion Chamber, Mayur Panduranga Kodikal

Electronic Theses and Dissertations

Lean burn has been considered an effective strategy to improve the thermal efficiency of spark-ignition engines. Under lean or diluted conditions, however, the combustion speed is reduced. Therefore, to speed up the combustion, in-cylinder turbulence is induced which may impede the spark initiation. This research aims to quantify the turbulence in a constant volume optical combustion chamber.

An Improved Delayed Detached Eddy Simulation (IDDES) study was done to understand the turbulence characteristics of the flow in the optical chamber. Spark anemometry was used to obtain a relationship between the spark plasma evolution and freestream velocity. Finally, this technique has been …

The Impact Of High Voltage Electrode Diameter On Spark Discharge Process, Jiaming Zhang

Electronic Theses and Dissertations

The ever-growing demands to meet the exhaust emission regulations and fuel economy requirements, drive the development of modern spark ignition (SI) engines towards lean or diluted conditions at boosted intake pressure and with intensified charge motions. Boosted in-cylinder pressure conditions require additional energy to initiate the spark discharge, thereby challenging the ignition system. Additionally, the geometry of the spark plug has a profound influence on the spark discharge characteristics. The main objective of this research is to study the impact of high voltage electrode diameter on breakdown voltage and equivalent spark gap resistance at elevated background pressures (1-25 bar abs.). …

Interfacial Heat Transfer In Squeeze Casting Of Cast Al Alloy A380 And Mg Alloy Az91 And Wrought Alloy Az31, Luyang Ren

Electronic Theses and Dissertations

The weight reduction of vehicles and airplanes in the automotive and aerospace industries is urgently needed due to the government regulation and market demand. To satisfy engineering performance of lightweight auto and aero components, high strength light alloys such as aluminum (Al) or magnesium (Mg) alloys are usually adopted. This study was intended to explore a solution for casting high strength cast and wrought Al and Mg alloys. Before light alloys can be utilized for mass production, critical processing parameters need to be accurately determined. The interfacial heat transfer coefficient is one of the most important factors in casting processes. …

Mechanical Properties Of Nanomodified Hybrid Gfrp Composite Materials, Micah Rop Kimutai

Electronic Theses and Dissertations

The mechanical behavior of the nanomodified hybrid epoxy matrix was investigated in glass fiber reinforced plastics (GFRP). In this study, five nanocomposites enriched with as received halloysite, nanomer I.28E, HNT-APTES, and the hybrid combinations of the two HNTs with the nanomer I.28E were successfully fabricated. To evaluate the effects and morphological characteristics of the individual fillers and the hybrid configurations on the epoxy resin matrix, TGA, DSC, and DMA were analyzed. To understand the effect of the five configurations on the neat GFRP laminate, mode I interlaminar fracture toughness, tensile, and vibration properties were investigated. Electron microscopy testing techniques were …

Reduced Exhaust Emissions Through Blending N-Butanol With Ultra Low Sulfur Diesel And Synthetic Paraffinic Kerosene In Reactivity Controlled Compression Ignition Combustion, Remi Gaubert

Electronic Theses and Dissertations

Increasing restrictions on the emitted exhaust emissions in diesel engines are becoming a more challenging task than in previous years. An electronic common rail fuel injection system and a port fuel injection (PFI) system were developed for an experimental engine to research dual fuel combustion. The experimental research was conducted at 1500 rpm and 4, 5, and 6 bar indicated mean effective pressure (IMEP). n-Butanol was port fuel injected at a 60% by mass fraction coupled with direct injection (DI) of three fuels, including ultra-low sulfur diesel (ULSD RCCI), a 50-50 wt-% blend of ULSD and butanol (ULSD-Bu RCCI), and …

Computational Fluid Dynamics Modeling Of The Effects Of Water Injection In A Diesel Engine, Rabun Z. Wallace

Electronic Theses and Dissertations

Water injection has been used in internal combustion engines for many years. It has been used to cool combustion temperatures, reduce emissions, and in some instances clean carbon buildup from the cylinder. Research has shown that the water to fuel mass ratio is most effective between 20-30%, so the upper and lower limit were used for simulations in Converge CFD. To validate the CFD model, a case without water injection was compared to experimental data from Sandia National Laboratory. The predicted in-cylinder pressure and heat release rate showed good agreement with the experimental data. Cases were run with the injection …