Mechanical Engineering Commons^™

Study Of Chaotic Ultrasound And Frequency Sweep Excitations In Sonic Ir Nde Technology, Ding Zhang

Wayne State University Dissertations

Sonic Infrared (IR) Imaging Nondestructive Evaluation (NDE) technology has shown inherent advantages, such as fast detection for all direction and all dimension flaws, for both metal and composite materials. The purpose of this dissertation is to study and investigate the physical process of two most important methods, frequency sweep excitation and chaotic excitation, to improve the defect detection ability of Sonic IR technology.

The tool used in our study is known as finite element analysis (FEA). According to test process of Sonic IR technology, some special technologies were developed in FEA simulation, such as creating cracks with flat contact surfaces …

Effect Of Cetane Number And Volatility On Autoignition And Combustion Of Alternative Fuels And Their Surrogates, Ziliang Zheng

Wayne State University Dissertations

Diesel engine has become a popular choice for trucks, trains, boats, and most other heavy-duty applications. The inherent benefits of diesel engine are high thermal efficiency and specific power output, but there is a concern about high levels of engine-out NOx and particulate matter emissions, which is a major contributor in environment pollution. Moreover, concern about the crisis of crude oil reserves, increasing gas price, trade deficit, and homeland security enhances the interests in alternative fuels.

Unlike conventional diesel fuel, alternative fuels have wide range of properties, such as volatility, cetane number, density, viscosity and lower heating value, which influence …

High-Performance Accelerometer Based On Asymmetric Gapped Cantilevers For Physiological Acoustic Sensing, Yating Hu

Wayne State University Dissertations

Continuous or mobile monitoring of physiological sounds is expected to play important role in the emerging mobile healthcare field. Because of the miniature size, low cost, and easy installation, accelerometer is an excellent choice for continuous physiological acoustic signal monitoring. However, in order to capture the detailed information in the physiological signals for clinical diagnostic purpose, there are more demanding requirements on the sensitivity/noise performance of accelerometers. In this thesis, a unique piezoelectric accelerometer based on the asymmetric gapped cantilever which exhibits significantly improved sensitivity is extensively studied. A meso-scale prototype is developed for capturing the high quality cardio and …

Jp-8 Surrogates For Diesel Engine Application: Development, Validation, And Cfd Simulation, Amit Shrestha

Wayne State University Dissertations

Recently, diesel engine cycle simulation has been acknowledged as an effective way for the development and performance optimization of compression ignition engines operating on a variety of fuels. The goal of this research was, therefore, to develop a JP-8 surrogate with a limited number of fuel components so that its chemical mechanism could be developed for its use with computational fluid dynamics (CFD) codes for enabling time-efficient diesel engine cycle simulation. In order to achieve this goal, a new approach was developed for the formulation of surrogate for compression ignition engine application. The development approach required the surrogate to match …

Evaluation Of Nozzle Geometry On High Pressure Gasoline Direct Injection Spray Atomization, Mark Shost

Wayne State University Dissertations

This research presents a critical study of injector nozzle geometry on high-pressure Gasoline Direct Injection, GDi, injector spray morphology. The study was conducted with the aid of multi-fluid Volume-of-Fluid, Large-Eddy-Simulation, VOF-LES, method. Alternative nozzle geometries, that are the subject of current interest including varying nozzle hole length to diameter ratio, counter-bore presence and nozzle-hole skew-angle geometry, are studied in detail in order to provide insight into their specific influence on spray plume targeting and jet primary breakup characteristics. A comparison of the simulation results with near-field shadowgraph and Mie scatter imaging as well as phase-contrast x-ray imaging is provided. When …

Thermal And Cooling Systems Modeling Of Powertrain For A Plug -In Parallel-Through-The-Road Hybrid Electric Vehicle, Mengjia Cao

Wayne State University Theses

Thermal modeling and control play an ever increasing role with hybrid electric vehicle (HEV) design and development for improving overall vehicle energy efficiency, and to account for additional thermal loading from electric powertrain components such as electric motor, motor controller and battery pack.

This thesis presents a complete development process for an efficient modeling approach with integrated control strategy for the thermal management of plug-in HEV in a parallel-through-the road (PTTR) architecture, adopted by Wayne State University Hybrid Warriors for their Department of Energy's EcoCAR2 Plugging in to the Future Competition.

The frameworks of this project include simulating the thermal …

Investigation Of Ion Current Signal In A Modern Automotive Diesel Engine, Rojan Mathew George

Wayne State University Theses

Research is driven towards finding an alternative or extender to the conventional diesel fuel for compression ignition engines. Such alternative fuels have wide ranges of physical and chemical properties which is not suitable for CI engines. Therefore, experimental investigation to understand the effects of different fuels on engine performance, combustion, and emissions are necessary. A complete understanding of ion current signal during heterogeneous diesel combustion has not yet been made. Implementation of ion current signal as a feedback in diesel engines, during all operating conditions needs further research and understanding.

This thesis covers the investigation of ion current signal characteristics …

An Investigation Of Kinetic Effects Of Split Injection Timing On Low Temperature Combustion, Tejaswini A. Kamble

Wayne State University Theses

Low temperature combustion (LTC) modes of operating internal combustion engines are of great interest for their potential to achieve high thermal efficiencies while maintaining low nitrogen oxide (NOX) and particulate matter emissions below levels requiring costly after-treatment systems. While various strategies for realizing LTC have been developed, including homogeneous charge compression ignition (HCCI), reactivity controlled compression ignition (RCCI) and premixed charge compression ignition (PCCI), a common challenge is the control of the kinetically-driven auto-ignition processes over appreciable load ranges.

This study examines the chemical kinetics of split-injection timing and the kinetic effect of this parameter on combustion phasing and pressure …

Simulations And Measurements Of Fuel Film Using Refractive Index Matching Method, Fengkun Wang

Wayne State University Theses

ABSTRACT

SIMULATIONS AND MEASUREMENTS OF FUEL FILM USING REFRACTIVE INDEX MATCHING METHOD

by

FENGKUN WANG

APRIL 2014

Advisor: Dr. Ming-Chia Lai

Major: Mechanical Engineering

Degree: Master of Science

Direct Injection (DI) has been known for its improved performance and efficiency in gasoline spark-ignition engines. However, wall wetting is inevitable and the source of UHC and PM. In order to take advantage of the GDI technology, it is important to investigate spray wall interactions in detail.

Numerical and experimental studies are carried out for spray and wall impingements in an optical constant volume vessel. The fuel film was measured spatially and …

Experimental Validation Of A Robust Surge Speed Controller For Marine Surface Vessels, John Foehr

Wayne State University Theses

The focus of the current work is on providing experimental validation for the robust performance and good tracking characteristic of a surge speed controller for autonomous piloting of an under-actuated 16 ft boat in the completely uncontrolled setting of open-water Lake Saint Clair, Michigan. The controller is designed based on the sliding mode methodology and completely ignores the dynamics of the marine surface vessel (MSV) in its formulation. The testing was conducted under considerable unstructured uncertainties and unpredictable environmental disturbances induced by waves, sea-currents, and wind. The experimental results serve to validate the robust tracking characteristic of the controller and …

The Mechanics Of Momentum Transfer From Explosive Charges Buried In Water, In Sand, And In Sand With Fines, David M. Fox

Wayne State University Dissertations

Physical tests involving full-scale systems subjected to blast loads are expensive. The development of more accurate computational and analytical methods to better understand and predict the mechanics of mine blast phenomena could be used to reduce the cost of development of mine protected vehicles and protective equipment for personnel involved in demining and similar activities.

Although the science associated with air blast and blast-related ground shock phenomena is very extensive, that of mine blast, involving explosives buried in soil, is less well developed. In this work, theoretical, experimental, and computational methods are synthesized to better understand some of the mechanisms …

Combustion Visualization And Particulate Matter Emission Of A Gdi Engine By Using Gasoline And E85, Po-I Lee

Wayne State University Dissertations

In order to increase engine efficiency as well as to reduce emission, optimizing combustion is always the challenge in research and product development. Gasoline direct injection (GDI) engines have been popularized due to its higher power density, fuel efficiency, and the possibility for advanced engine technologies over conventional port-fuel-injection (PFI) gasoline engines. However, many issues are heavily investigated, such as air-fuel mixing preparation, fuel wall-wetting, higher HC and PM emissions, catalytic convertor efficiency, knocking, and pre-ignition. Besides, advanced technologies represent higher production cost.

Because of the limited resource of petroleum-based fuels, ethanol is deemed as the alternative fuel for gasoline …

Communication Protocol Design Considerations For Highway Vehicle Platoons And Enhanced Networked Robustness By Stochastic Dithers, Lijian Xu

Wayne State University Dissertations

Highway platooning of vehicles has been identified as a promising framework in

developing intelligent transportation systems. By autonomous or semi-autonomous

vehicle control and inter-vehicle coordination, an appropriately managed platoon can

potentially offer enhanced safety, improved highway utility, increased fuel economy,

and reduced emission. This thesis is focused on quantitative characterization of impact

of communication information structures and contents on platoon safety. By

comparing different information structures which combine front sensors, rear sensors,

and wireless communication channels, and different information contents such

as distances, speeds, and drivers' actions, we reveal a number of intrinsic relationships

between vehicle coordination and communications in …

Non-Linear Robust Observers For Systems With Non-Collocated Sensors And Actuators, Constantine Mastory

Wayne State University Dissertations

Challenges in controlling highly nonlinear systems are not limited to the development of sophisticated control algorithms that are tolerant to significant modeling imprecision and external disturbances. Additional challenges stem from the implementation of the control algorithm such as the availability of the state variables needed for the computation of the control signals, and the adverse effects induced by non-collocated sensors and actuators.

The present work investigates the adverse effects of non-collocated sensors and actuators on the phase characteristics of flexible structures and the ensuing implications on the performance of structural controllers. Two closed-loop systems are considered and their phase angle …

Load Path Uncertainty In A Wood Structure And The Effect On Structural Reliability, Wenqi Wang, Christopher D. Eamon

Civil and Environmental Engineering Faculty Research Publications

The roof truss bearing points of a light-framed wood house were instrumented with load cells. It was found that under dead load alone, symmetric and theoretically identical truss reactions have significant variation. A similar degree of reaction discrepancy was found under the application of uplift pressures caused by hurricane winds. Analysis revealed that the majority of this discrepancy is caused by inherent uncertainties in load path. Although uncertainties in load magnitude and material resistance are accounted for in design by use of appropriate load and resistance factors, load path is generally taken to be deterministic. In this study, load path …

Reliability Analysis Of Reinforced Concrete Columns Exposed To Fire, Christopher D. Eamon, Elin A. Jensen

Civil and Environmental Engineering Faculty Research Publications

A reliability analysis is conducted on reinforced concrete columns subjected to fire load. From an evaluation of load frequency of occurrence, load random variables are taken to be dead load, sustained live load, and fire temperature. Resistance is developed for axial capacity, with random variables taken as steel yield strength, concrete compressive strength, placement of reinforcement, and section width and height. A rational interaction model based on the Rankine approach is used to estimate column capacity as a function of fire exposure time. Various factors were considered in the analysis such as fire type, load ratio, reinforcement ratio, cover, concrete …

Reliability-Based Design Optimization Of Concrete Flexural Members Reinforced With Ductile Frp Bars, Bashar Behnam, Christopher D. Eamon

Civil and Environmental Engineering Faculty Research Publications

In recent years, ductile hybrid FRP (DHFRP) bars have been developed for use as tensile reinforcement. However, initial material costs regain high, and it is difficult to simultaneously meet strength, stiffness, ductility, and reliability demands. In this study, a reliability-based design optimization (RBDO) is conducted to determine minimum cost DHFRP bar configurations while enforcing essential constraints. Applications for bridge decks and building beams are considered, with 2, 3, and 4-material bars. It was found that optimal bar configuration has little variation for the different applications, and that overall optimized bar cost decreased as the number of bar materials increased.

Analysis Of Alternative Ductile Fiber-Reinforced Polymer Reinforcing Bar Concepts, Bashar Behnam, Christopher D. Eamon

Civil and Environmental Engineering Faculty Research Publications

Steel-reinforced concrete structural components are often associated with significant maintenance costs as a result of reinforcement corrosion. To mitigate this problem, fiber-reinforced polymer (FRP) bars have been used in place of traditional steel reinforcement for some applications. The non-ductile response of typical FRP bars is a concern, however. To overcome this problem, hybrid ductile FRP (HDFRP) bars have been developed for use in concrete flexural members with resulting ductility indices similar to sections reinforced with steel. In this study, five different HDFRP bar concepts are analyzed and compared in terms of ductility, stiffness, and relative cost. Of primary interest is …

Resistance Factors For Ductile Frp-Reinforced Concrete Flexural Members, Bashar Behnam, Christopher D. Eamon

Civil and Environmental Engineering Faculty Research Publications

To prevent damage caused by corroding reinforcement, fiber reinforced polymer (FRP) reinforcing bars have been used in place of steel in a relatively small but increasing number of structures in the civil infrastructure. A concern with the use of traditional FRP bars, however, is the resulting lack of ductility. This problem has been overcome with the development of a new generation of composite reinforcement, ductile hybrid FRP (DHFRP) bars. However, standards that address the design of DHFRP bars are unavailable, and appropriate resistance factors for the use of DHFRP reinforcement are unknown. In this study, a reliability analysis is conducted …

Reliability Analysis Of Rc Beams Exposed To Fire, Christopher D. Eamon, Elin A. Jensen

Civil and Environmental Engineering Faculty Research Publications

A procedure for conducting reliability analysis of reinforced concrete beams subjected to a fire load is presented. This involves identifying relevant load combinations, specifying critical load and resistance random variables, and establishing a high-temperature performance model for beam capacity. Based on the procedure, an initial reliability analysis is conducted using currently available data. Significant load random variables are taken to be dead load, sustained live load, and fire temperature. Resistance is in terms of moment capacity, with random variables taken as steel yield strength, concrete compressive strength, placement of reinforcement, beam width, and thermal diffusivity. A semi-empirical model is used …

Effect Of Intake Temperature And Boost Pressure On The Auto-Ignition Of Fuels With Different Cetane Numbers And Volatilities, Chandrasekharan Jayakumar

Wayne State University Dissertations

The aim of this research is to investigate the effect of air inlet temperature and boost pressure on the auto-ignition of fuels that have different CNs and volatilities in a single cylinder diesel engine. The inlet air temperature is varied over a range of 30°C to 110°C at a constant intake pressure of 1.1 bar. The boost pressure is varied from 1.1 bar to 1.5 bar at a constant intake temperature of 60°C. All engine tests are run at steady-state conditions. The fuels used are ultra-low-sulfur-diesel (ULSD), JP-8 (two blends with CN 50 & 31) and F-T SPK. Detailed analysis …

Exergetic Analysis Of Hydrogen Combustion Involving Electronically Excited Species, Devon Alan Washington

Wayne State University Dissertations

Plasma-assisted combustion (PAC) is a growing field of research that involves using nonthermal plasma (NTP) to enhance combustion. PAC research involves modeling reaction mechanisms and chemical kinetics. Exergy analysis of combustion devices focuses on combustion irreversibility, including mixing, internal heat transfer, and oxidation. This novel research project merges these two branches of research.

The focus of this work is the application of exergy analysis to PAC systems, to analyze the effect introducing NTP has on trends in exergy destruction associated with oxidation during hydrogen combustion. This was accomplished by developing a plug flow reactor model using the chemical simulation tool …

Simulations And Experiments Of Fuel Injection, Mixing And Combustion In Di Gasoline Engines, Yi Zheng

Wayne State University Dissertations

Direct Injection (DI) has been known for its improved performance and efficiency in gasoline spark-ignition engines. In order to take all the advantages of the GDI technology, it is important to investigate in detail the interactions of fuel spray and combustion system, such as air-fuel mixing, in-cylinder flow development, surface wetting, and turbulence intensity. The characterizations of the internal nozzle flow of DI injector are first studied using the multidimensional computational fluid dynamic (CFD) simulation. In the meanwhile the numerical and experimental studies are carried out to observe the external spray and wall impingements in an optical constant volume vessel. …

Characteristics Of Cold Start Of A Diesel Engine Using Jp8 And Ulsd Fuels, Madhushankar Palanisamy

Wayne State University Theses

This study involves the cold start testing of ULSD and JP8 fuels on the 6 cylinder 7.2 liter turbocharged diesel engine at various ambient temperatures as low as 0oF for JP8 fuel and 10oF for ULSD fuel. Cycle by cycle analysis of the cold start transient data, along with the effects of variation in ambient temperature on the engine cranking speed and in cylinder motoring pressure were analyzed and presented. It was found that the reduction in ambient temperature resulted in prolonged cranking periods along with the longer time taken to reach idling speed as well as increased combustion instability. …

Structure Borne Noise Analysis Using Helmholtz Equation Least Squares Based Forced Vibro Acoustic Components, Logesh Kumar Natarajan

Wayne State University Dissertations

This dissertation presents a structure-borne noise analysis technology that is focused on providing a cost-effective noise reduction strategy. Structure-borne sound is generated or transmitted through structural vibration; however, only a small portion of the vibration can effectively produce sound and radiate it to the far-field. Therefore, cost-effective noise reduction is reliant on identifying and suppressing the critical vibration components that are directly responsible for an undesired sound. However, current technologies cannot successfully identify these critical vibration components from the point of view of direct contribution to sound radiation and hence cannot guarantee the best cost-effective noise reduction.

The technology developed …

Ionization In Diesel Combustion For On-Board Diagnostics And Engine Control, Tamer Hassan Badawy

Wayne State University Dissertations

Diesel engines have been known for their high thermal efficiency and specific power output, but there is concern about engine-out NOx and particulate matter emissions. To meet the current emission standards, advanced diesel engines are fitted with electronically controlled fuel injection systems and sophisticated and expensive after-treatment devices. Further improvements are still needed to meet future goals in better fuel economy and the more stringent emission standards. In order to meet these goals, there is a need for the control of the combustion process to reduce engine-out emissions in real-time and reduce the demand on the after-treatment devices. This requires …

Impact Damage Analysis Of Balsa Wood Sandwich Composite Materials, Suof Abdalslam

Wayne State University Dissertations

No abstract provided.

Experimental Investigation And Development Of An Extended Two Color Method (Etcm) With Application To Internal Combustion Engines, Elena Florea

Wayne State University Dissertations

The internal combustion engine is on a continuous path of improvement to reduce exhaust gaseous emissions and improve fuel economy. While recent trends in diesel engine development have lowered the EGR requirements, future regulatory pressure will likely result in a reversed trend in the future.

Given this, it is of interest to improve the application range of diagnostic tools such as the two color method (TCM) typically used in evaluating the properties of engine soot, such as temperature and volume fraction. This optical diagnostic method relies on the use of the light emitted by the soot particles along with a …

Ion Current Signal Detection During Cold Starting And Idling Operation In A Diesel Engine, Sanket Anil Gujarathi

Wayne State University Theses

Cold starting of diesel engines is characterized by inherent problems such as long cranking periods and combustion instability leading to an increase in fuel consumption and the emission of high concentrations of hydrocarbons which appear as white smoke. Accordingly, a signal indicative of combustion during cold starting and idling operation is important for combustion and emission control. The ion current signal has been considered for the feedback control of both gasoline and diesel engines. However, the ion current signal produced from the combustion of the heterogeneous charge in diesel engines is weaker compared to that produced from the combustion of …

Fatigue Behavior And Microstructure Examination Of Aisi D2 Trim Dies, Xinchen Wang

Wayne State University Theses

AISI D2 steels are widely used as tools for forming, drawing and trimming dies due to its high wear resistance, high compressive strength and low distortion, and its performance as a trim die material for cutting ultra-high strength steels (at 1GPa or above) is investigated in this study.

To simulate the production trimming process under a laboratory accelerated fatigue condition, a trim die simulator and testing technique have been developed. In this test 1" cubic die samples were used that offers total 12 cutting edges of 6 different material grain orientations in shearing, and with adjustable die clearance. A non-contact …