Mechanical Engineering Commons^™

Performance Evaluation Of A Novel Diesel Fuel Air Separation And Filtration System For An Indirect Injection Diesel Engine, Michael Ray Hess

Masters Theses

"The objective of this research was to evaluate an air/fuel separation system known as a Fuel Preporator. The device's efficacy was determined by studying the effect of air entrainment on engine performance and fuel consumption of a General Motors 6.5 L naturally aspirated indirect injection (IDI) diesel engine. A test bed was developed to accommodate the test engine and test methods were adapted from federal regulations for steady-state engine testing (40 CFR 89 Subpart E). Cases of 0%, 5%, 10%, and 20% volumetric air entrainment were investigated for engine operation with and without the Fuel Preporator. Key measured engine performance …

Freeze Extrusion Fabrication Of 13-93 Bioactive Glass Scaffolds For Bone Repair, Nikhil D. Doiphode

Masters Theses

"We have investigated Freeze Extrusion Fabrication (FEF) of 13-93 bioactive glass to fabricate three dimensional scaffolds for bone tissue engineering. Bioactive glass paste was prepared for consistent extrusion through micro-nozzle and controlled porosity scaffolds were fabricated using additive manufacturing FEF. CAD models were prepared for different scaffold designs and computer controlled layer-by-layer deposition of pseudoplastic paste was carried out to in accordance. Liquid nitrogen assisted freezing of pastes was used for the consolidation of deposited layers. Post processing binder burnout and sintering schedules were designed for evaporation of organic binder and densification of glass. Sintering shrinkage was measured, and X-ray …

Thermodynamic Based Modeling For Nonlinear Control Of Combustion Phasing In Hcci Engines, Joshua Bradley Bettis

Masters Theses

"Low temperature combustion modes, such as Homogeneous Charge Compression Ignition (HCCI), represent a promising means to increase the efficiency and significantly reduce the emissions of internal combustion engines. Implementation and control are difficult, however, due to the lack of an external combustion trigger. This thesis outlines a nonlinear control-oriented model of a single cylinder HCCI engine, which is physically based on a five state thermodynamic cycle. This model is aimed at capturing the behavior of an engine which utilizes fully vaporized gasoline-type fuels, exhaust gas recirculation and intake air heating in order to achieve HCCI operation. The onset of combustion, …

Influence Of Flow Baffles On Mixing Of Two Air Streams Flowing In A Mixing Chamber With Dissimilar Temperatures: A Computational Study, Abdulmunam Salem Shaban

Masters Theses

"One of the most important components of heating, ventilation, and air conditioning (HVAC) is an air handling unit (AHU) which is used to condition and mix air that arrives from outside the building (OA) and return air (RA) that exits from the indoor space. Poor mixing between the warm return air and the cold outside air often leads to air stratification in AHU, which results in various problems, such as, nuisance trips of low temperature safety thermostats, freezing of chilled or hot water coils in a stratified subfreezing air stream and loss of control when sensors cannot read the true …

Finite Element Analysis And Fatigue Test On The Bicuspids To Support Theory Of Abfraction, Madhuchandra Mahadevaswamy

Masters Theses

"Abfraction is a small crack or notch found at the cervical areas of a teeth due to the loss of enamel tissues in the teeth. Proposed explanations for are that it is caused by toothbrush abrasion, acid erosion, and the mechanical forces applied on the teeth due to chewing, biting, tongue activity. There is disagreement among dentists as to the primary causes of abfraction. Some dentists believe that abfraction is caused by toothbrush abrasion and erosion due to acidic food and drinks. Other dentists believe that tensile and compressive forces acting on the teeth from non-axial, cyclical loading over an …

Design And Development Of Microwire Feeder For Laser Applications, Amogh J. Shenoy

Masters Theses

"This thesis focuses on the design and development of a microwire feeder for laser applications. The use of wire-feeders in laser welding and electrical discharge machining applications has been prominent which can handle wire of 0.25 mm and it can go up to 10.0 mm in other applications. Development of microwire handling devices is complicated and difficult due to its low buckling strength; the need for high accuracy for its use; and the harsh environment it is exposed to, in laser applications. This paper presents a systematic methodology for the design and development of a high-precision microwire handling device. This …

Validation Of Driving Simulator And Driver Perception Of Vehicle Mounted Attenuator Markings In Work Zones, Durga Raj Mathur

Masters Theses

"This research work sought to validate the driving simulator at Missouri University of Science and Technology and to evaluate the vehicle mounted attenuator (VMA) markings for various times of day. For comprehensive validation of the driving simulator, a framework is proposed which is demonstrated using a fixed-base driving simulator. Objective and subjective evaluations were conducted, and validation of the driving simulator was performed at specific locations and along the highway. Field data were collected for a partial lane closure using a global positioning system (GPS) along the work zone and supplemented with video recordings of traffic data at specific locations …

Quantification Of Product Color Preference In A Utility Function, Hannah L. Turner

Masters Theses

"Currently, many marketing and engineering tools exist to help a designer optimize quantitative attributes of a product, such as height, weight, volume, or cost. However, these methods cannot effectively take into consideration aesthetic attributes of a product, or any other attributes for which there is no understood functional relationship between the attribute's potential values and the consumer's preference. This research has begun the work of developing this necessary functional relationship for the aesthetic attribute of color and has created a methodology for further research. To do this, colors were represented by their red, green, and blue light components, and preference …

Implementation Of Integrated Function Structure And Object-Oriented Design Framework, Qiong Gao

Masters Theses

"The function structure method is commonly used in mechanical product design. Although a function structure allows defining all the functions of the components of a product and their interactions, it does not have an effective architecture for the software design of a mechatronic product. An integrated function structure and object-oriented design framework was recently developed to overcome this disadvantage. In this thesis, the implementation of this framework to design several products in different categories, including an inkjet printer, and electric screwdriver and a vacuum cleaner, is discussed. The design results obtained using the new framework are compared to the design …

Mechanical Properties And Microstructure Study For Direct Metal Deposition Of 316l Stainless Steel, Tian Fu

Masters Theses

"Direct metal deposition or laser cladding is a process capable of producing fully dense and net shape metal products and this process could be used on coating metal components in various engineering applications. This process has fast heating and cooling rates which can improve the surface hardness and provide excellent adhesion through metallurgical bond between coating material and substrate. This paper evaluated the laser deposited 316L stainless steel coating on 4340 steel, which is widely used for aircraft landing gear applications. The microstructure, micro-hardness and quantitative EDS were explored to verify the coating properties. The desired homogeneous microstructure and high …

Maskless Additive Manufacturing Of Micro Structures By Laser Sintering Of Nanoparticles, Vivekram Ramanathan

Masters Theses

"The focus of this study was to investigate an alternate microfabrication process of sintering nanoparticles using a patterned laser light to generate two dimensional (2D) and three dimensional (3D) geometries. With trends of producing electronic and medical devices using cheaper and faster technologies, a new procedure was developed to deposit and bond miniature patterns of silver nanoparticles onto silicon substrates.

The process consists of spraying silver nanoparticles onto the substrate while a patterned or modulated laser beam is focused onto the sprayed nanoparticles. These nanoparticles exposed under the modulated laser light undergo partial melting or sintering and adhere to the …

Decentralized Coordinated Ilc System Design And Transient Growth Control Using Iteration-Varying Filter, Qing Liu

Masters Theses

"In automation control area, with the increasing demand in task complexity and high control precision, coordination between systems is required. There are mainly two types of coordinated systems, decentralized and centralized. This thesis is focused on a large array of coordinated systems, and the decentralized structure is preferred. To achieve high control precision in a coordinated system, many existing approaches may work, and in the system performing the repeating process, Iterative Learning Control (ILC) is a useful approach. Therefore, in this thesis, a decentralized coordinated ILC system is proposed and analyzed. The proposed control system is especially useful in coordinating …

Synthesis And Characterization Of Microspheres For Controlled Release, Gurpartap Singh Sandhu

Masters Theses

"Synthetic hydroxyapatite (HAp, (Ca₁₀(PO₄)₆(OH)₂) has always been of interest in medical applications because of its similarities to inorganic bone matrix. It has been used in biomedical applications for bone repair and substitution due to its biocompatibility. However, there are some differences in the stoichiometry, composition, and mechanical properties of human bone as compared to pure HAP. HAp particles have been successfully used as drug delivery carriers which deliver the drug to the affected part of the body and the remaining apatite gets degraded by the physiological processes in the body. In the present work, emphasis was on developing mechanically stronger …

Evaluation Of Metal Detection Audio Alert Signals Of An/Pss-14 By Means Of Real Time Visualization, Sandesh Srikantaiah Chandrashekar

Masters Theses

"The sweep arm of the AN/PSS-14 Landmine Detector attached to an independent visualization device will transform the AN/PSS-14 into a hand-held data acquisition system for conversion of real time MD and GPR audio alert signals into captured visual trace displays on an on-board PDA computer screen so that momentary sounds of millisecond durations can be captured and displayed for visual scrutiny and interpretation by analytical on-board data processing procedures. This is a part of a two-man team that is developing a visual data adapter for the AN/PSS-14 Landmine Detector where the current thesis is concentrating only on MD audio alerts. …

Automation Of Cad Model Based Assembly Simulations Using Motion Capture, Anup Madhav Vader

Masters Theses

"The manufacturing industry often uses text and video as a supplement for worker training procedures. Unfortunately, text is often difficult to follow and video lends itself to occlusion issues. CAD based animations of assembly operations can overcome these shortcomings while offering greater potential for operations analysis and simulation flexibility. However, creating such CAD based training simulations manually is a time intensive task and many a times fail to reveal the practical assembly issues faced in the real world. Thus, it is highly beneficial to be able to automate these simulations using motion capture from a physical environment. This thesis research …

Design And Critical Performance Evaluation Of Horizontal Axis Hydrokinetic Turbines, Suchi Subhra Mukherji

Masters Theses

"The current work discusses the hydrodynamic performance of horizontal axis hydrokinetic turbines (HAHkT) under different turbine geometries and flow conditions. Hydrokinetic turbines are a class of zero-head hydropower systems which utilize kinetic energy of flowing water to drive a generator. However, such turbines often suffer from low-efficiency. A detailed computational fluid dynamics study was performed using a low-order k-[omega] SST (Shear Stress Transport) turbulence model to examine the effect of each of tip-speed ratio, solidity, angle of attack and number of blades on the performance of small HAHkTs with a power capacity of 10 kW. The numerical models (both two-dimensional …

Neural Mrac Based On Modified State Observer, Yang Yang

Masters Theses

"A new model reference adaptive control design method with guaranteed transient performance using neural networks is proposed in this thesis. With this method, stable tracking of a desired trajectory is realized for nonlinear system with uncertainty, and modified state observer structure is designed to enable desired transient performance with large adaptive gain and at the same time avoid high frequency oscillation. The neural network adaption rule is derived using Lyapunov theory, which guarantees stability of error dynamics and boundedness of neural network weights, and a soft switching sliding mode modification is added in order to adjust tracking error. The proposed …

Finite Element Modeling Of Bird Strikes And Parametric Evaluation Using Design Of Experiments (Doe), Venkata Varaha Raja Naga Prathyush Bheem Reddy

Masters Theses

"One of the major threats to Aviation industry is the in-flight impact of birds. Aircraft windshields are intensively vulnerable to damage and hence need a certification requirement for a proven level of impact resistance. Bird strike experiments are very expensive and henceforth explicit numerical modeling techniques have grown importance. This compilation mainly relies on the theory of hydrodynamic impact and addresses basic shockwave equations. A smooth particle hydrodynamics based approach is chosen and the numerical simulation is carried out using contact-impact coupling algorithm. The simulation is run using the nonlinear explicit finite element code LSDYNA ver.971, developed by Lawrence Livermore …

A Comparison Of Case-Based Reasoning And Regression Analysis Approaches For Cost Uncertainty Modeling, Karan Banga

Masters Theses

"This thesis presents case-based reasoning approach for estimating the cost and modeling cost uncertainty of a new product in the concept selection stage. Case-based reasoning (CBR) is an approach which uses old cases/experiences to understand and solve new problems. The CBR approach consists of creating a knowledge-base (or database) containing past cases (products), defining a new case (concept), retrieving cases similar to the new case, and adjusting the solution of the retrieved cases to the new case. The first paper compares case-based reasoning, in studying the effects of varying design attribute specifications on cost estimation accuracy and cost distribution reliability. …

Integration And Characterization Of An Electrical Storage System For A Hydrogen Fuel Cell Plug-In Hybrid Electric Vehicle, Edward Alexei Anculle Arauco

Masters Theses

"Hydrogen fuel cell hybrid vehicles are an advance technology that promises to solve the energy crisis in transportation and green houses emissions. Even more, Plug-in or extended range vehicles can add diversity in energy sources. Extended range vehicles have the capability to extract energy from the grid and hence reduce the cost of operation of the vehicle. EcoCAR: the NeXt Challenge is a Noth [sic] American competition with seventeen schools participating across North America. Missouri S&T is developing a Fuel Cell Plug-in Hybrid electric vehicle which has a large lithium-ion battery able to store 16 kWh. The fuel cell powertrain …

Energy Expenditure Analysis Of Redesigned Mechanical Assists For Medium Girder Bridge, Karthik Kumar

Masters Theses

"U.S. Army bridge crew soldiers perform tough manual material handling (MMH) tasks during the assembly of a Medium Girder Bridge (MGB). The bridge parts are very heavy and are manually lifted from pallets, carried to the construction site and assembled with other bridge parts. An energy expenditure study on the soldiers handling the bridge parts revealed that the energy expenditure rate of the soldiers exceeds the NIOSH prescribed safety limit of 3.5 Kcal/min. This leads to high risk of musculoskeletal disorders. The study deals with modifying the first redesign of mechanical assists for medium girder bridge (MGB) and studying the …

A Real-Time Visualization Of An/Pss-14 Audio Alert Signals For Land Mine Detection Validation, Nitin Kolekar

Masters Theses

"The central idea of the current research is visualization of audio alerts from AN/PSS-14. A visualization device connected to the arm of PSS-14 will show real-time display of MD and GPR Audio Alert signals from PSS-14. This visualization device displays both amplitude-time and spectral frequency-time formats of the signals. The latter format achieves visual separation of combined, simultaneous, MD and GPR alerts. The joint occurrence of MD and GPR signals in a specific time window confirms the presence of landmine. This window is defined by the time of occurrence of MD peak and time of occurrence GPR diffraction from onset …

Simulation Of Pem Fuel Cells: Validation Of Model And Incorporation Of Humidity Dynamics, Steven Francis Rodgers

Masters Theses

"Fuel cell technologies have been receiving increased attention by industry and researchers due to growing societal and inevitable economic pressures to find an alternative for fossil fuels. At the forefront of this is the demand for fuel cell models: models to elucidate fundamental physical phenomena underlying fuel cell function and models that are not computationally demanding yet reasonably accurate to allow designers to incorporate fuel cells into consumer products. One of the latter type has recently been developed based on a software package that is already in widespread use in the automotive industry for the simulation of mechanical, thermal, electrical, …

Slip Ramp Spacing Design For Truck Only Lanes Using Microscopic Simulation, Manoj Vallati

Masters Theses

"This research work proposes recommendations for slip ramp spacing between the TOLs and the general GPLs along Missouri rural interstate highways using a microscopic simulation model, VISSIM. Simulation of peak period rural traffic conditions indicated that heavy vehicle speeds were directly proportional to the lengths of the merge, diverge, and link sections. The proposed design recommendations for slip ramp spacing are based on the results of these section lengths. Design of experiments was carried out using a central composite design. As the slip ramp spacing depended heavily on the lane change behavior of drivers, a sensitivity analysis was performed of …