An Investigation Of Variable Valve Timing Effects On Hcci Engine Performance,
2014
Michigan Technological University
An Investigation Of Variable Valve Timing Effects On Hcci Engine Performance, Hrishikesh Abhay Saigaonkar
Dissertations, Master's Theses and Master's Reports - Open
The Homogeneous Charge Compression Ignition (HCCI) engine is a promising combustion concept for reducing NOx and particulate matter (PM) emissions and providing a high thermal efficiency in internal combustion engines. This concept though has limitations in the areas of combustion control and achieving stable combustion at high loads. For HCCI to be a viable option for on-road vehicles, further understanding of its combustion phenomenon and its control are essential. Thus, this thesis has a focus on both the experimental setup of an HCCI engine at Michigan Technological University (MTU) and also developing a physical numerical simulation model called the …
Test-Analysis Model Correlation And Calibration Of A Multi-Component Plastic Part,
2014
Michigan Technological University
Test-Analysis Model Correlation And Calibration Of A Multi-Component Plastic Part, Steven P. Carter
Dissertations, Master's Theses and Master's Reports - Open
The goal of this project is to learn the necessary steps to create a finite element model, which can accurately predict the dynamic response of a Kohler Engines Heavy Duty Air Cleaner (HDAC). This air cleaner is composed of three glass reinforced plastic components and two air filters. Several uncertainties arose in the finite element (FE) model due to the HDAC’s component material properties and assembly conditions. To help understand and mitigate these uncertainties, analytical and experimental modal models were created concurrently to perform a model correlation and calibration. Over the course of the project simple and practical methods were …
Reconciling Function- And Affordance-Based Design,
2014
Michigan Technological University
Reconciling Function- And Affordance-Based Design, Benjamin T. Ciavola
Dissertations, Master's Theses and Master's Reports - Open
Traditional engineering design methods are based on Simon's (1969) use of the concept function, and as such collectively suffer from both theoretical and practical shortcomings. Researchers in the field of affordance-based design have borrowed from ecological psychology in an attempt to address the blind spots of function-based design, developing alternative ontologies and design processes. This dissertation presents function and affordance theory as both compatible and complimentary. We first present a hybrid approach to design for technology change, followed by a reconciliation and integration of function and affordance ontologies for use in design. We explore the integration of a standard function-based …
Stock Aggregation Model And Virtual Archetype For Large Scale Retrofit Modelling Of Local Authority Housing In Ireland,
2014
Department of Architecture, Cork Institute of Technology, Cork, Ireland.
Stock Aggregation Model And Virtual Archetype For Large Scale Retrofit Modelling Of Local Authority Housing In Ireland, James Pittam, Paul D. O’Sullivan, Garrett O’Sullivan
Conference Papers
Developing representative archetypes using a bottom up approach for stock modelling is an excellent tool for evaluating the overall performance of the building stock; however it requires detailed analysis of the various building types. Currently there is no detailed housing data base for Local Authority housing in Cork City, Ireland that catalogues the housing stocks geometric properties and thermal characteristics for each typology. This study details a methodology to catalogue the LAH stock and build a detailed housing data base. The GIS web based mapping application Google Street View is used to identify 20 house typologies across 36 LAH developments; …
Thermal Conduction And Heat Generation Phenomena In Li-Ion Cells,
2014
University of Texas at Arlington
Thermal Conduction And Heat Generation Phenomena In Li-Ion Cells, Stephen Drake
Mechanical and Aerospace Engineering Dissertations - Archive
Cylindrical lithium ion (Li-ion) cells have demonstrated high power density and energy capacity among other energy storage devices. Despite their already widespread use, the thermal transport properties of cylindrical Li-ion batteries are not well documented and understood, while a sizable amount of work has been carried out for electrical, electrochemical, and materials optimization of Li-ion cells. These thermal phenomena are particularly important for high discharge rate batteries. With this uncertainty, if thermophysical properties are not accounted for in thermal models, the result may be a significant under-prediction or over-prediction of the temperature field in a Li-ion cell.Experimental techniques are described …
Unsteady Thrust Measurement Techniques For Pulse Detonation Engines,
2014
University of Texas at Arlington
Unsteady Thrust Measurement Techniques For Pulse Detonation Engines, Dibesh Dhoj Joshi
Mechanical and Aerospace Engineering Dissertations - Archive
Thrust is a critical performance parameter and its correct determination is necessary to characterize an engine. Many conventional thrust measurement techniques prevail. However, further developments are required for correct measurement of thrust in the case of a pulse detonation engine (PDE), since the entire thrust generation process is intermittent. The significant effect of system dynamics in the form of inertial forces, stress wave propagation and reflections initiated in the structure due to detonations and pulse-to-pulse interaction in a fast operating PDE further complicate the thrust measurement process. These complications call for a further, detailed study of the unsteady thrust characteristics. …
Experimental Investigation Of Nucleate Boiling And Thin-Film Evaporation On Enhanced Silicon Surfaces,
2014
University of Texas at Arlington
Experimental Investigation Of Nucleate Boiling And Thin-Film Evaporation On Enhanced Silicon Surfaces, Shailesh Malla
Mechanical and Aerospace Engineering Dissertations - Archive
The present work consists of two major studies. The first study investigates the effects of surface energy or wettability on nucleate pool boiling and the second study investigates the thin-film evaporative cooling for near junction thermal management. For the first study, effects of surface energy or wettability on critical heat flux (CHF) and boiling heat transfer (BHT) of smooth heated surfaces was studied in saturated pool boiling of water at 1 atm. For this purpose hydrophilic and hydrophobic surfaces were created on one side of 1cm x 1cm double-side polished silicon substrates. A resistive heating layer was applied on the …
Degradation Mechanics Of Bone And Bone Like Materials Via Multiscale Analysis,
2014
University of Texas at Arlington
Degradation Mechanics Of Bone And Bone Like Materials Via Multiscale Analysis, Md Farzad Sarker
Mechanical and Aerospace Engineering Dissertations - Archive
Bone fracture is a common health risk for older people suffering from bone disease like osteoporosis. The more severe the osteoporosis is the more structural degradation in bones occurs, which eventually makes bones more fracture prone. The mechanical behavior of bone depends on the structural response of bone constituents over a broad range of length scales spanning from the nanoscale collagen fibril level to the macroscale trabeculae level. As such, in order to understand bone fracture, it is important to know the structure-property relations of bone material over the entire length of scale. Surprisingly, a quantitative understanding of bone fracture …
Wind Field Estimation And Its Utilization In Trajectory And Input Prediction,
2014
University of Texas at Arlington
Wind Field Estimation And Its Utilization In Trajectory And Input Prediction, Jane-Wit Kampoon
Mechanical and Aerospace Engineering Dissertations - Archive
This dissertation work develops a method for onboard estimation of wind field with spatial and temporal variation based on local wind vector estimation and/or measurements from multiple aircraft flying in the same airspace. Aircraft flying in the same airspace of operation are considered airborne wind sensors scattered over the airspace because of the fact that aircraft carry along with them wind information inherent in their dynamics and kinematics. The onboard wind field estimation is formulated in the framework of parameter estimation based on various wind field models, which are different function of position and time. The online wind field estimation …
Electrowetting On Dielectric Digital Microfluidics For 3-Dimensional Cell Culture And Chemical Screening,
2014
University of Texas at Arlington
Electrowetting On Dielectric Digital Microfluidics For 3-Dimensional Cell Culture And Chemical Screening, Subin Mac George
Mechanical and Aerospace Engineering Dissertations - Archive
Microfluidic devices have allowed improved cell culture studies to be carried out by allowing greater spatiotemporal control over the cell environment while at the same time providing greater throughput, increased automation capabilities and reagent savings. To improve the relevancy of such studies, 3-dimensional (3D) cell culture has been attempted in microfluidic devices. 3D cell culture is known to better mimic and recreate the environment that cells in the body experience as compared to conventional 2-dimensional cell culture. However, incorporating 3D cell culture into conventional channel based microfluidic devices have proven to be challenging. Hydrogels which provide the 3D environment in …
Modeling, Estimation, And Analysis Of Unresolved Space Object Tracking And Identification,
2014
University of Texas at Arlington
Modeling, Estimation, And Analysis Of Unresolved Space Object Tracking And Identification, Laura Suarez Henderson
Mechanical and Aerospace Engineering Dissertations - Archive
The problem of orbit determination along with shape determination is significant. The orbit determination problem has been tackled for centuries by some of the greatest mathematicians and physicists. The issue of shape determination of space objects, although more recent, has also been addressed quite extensively. Nevertheless, these problems remain of great interest in the scientific and engineering community, and are addressed in this work. The greatest motivation for the tracking and identification of Earth orbiting objects is the ever-increasing population of space assets and man-made debris. It is of interest to implement new and better techniques to track and identify …
Investigation Of Wetting States On Microstructures After Liquid Drops Contact Groove Base,
2014
University of Texas at Arlington
Investigation Of Wetting States On Microstructures After Liquid Drops Contact Groove Base, Mingming Xiang
Mechanical and Aerospace Engineering Dissertations - Archive
Wetting properties of roughness surfaces have attracted a considerable attention because of both the scientific insight and the practical applications. One of the most intriguing topics of wetting is the so-called Cassie-Baxter and Wenzel transition. Recently, theoretical and experimental works have been done to explore this transition on microstructure-formed surfaces. One of the criteria that most commonly used to judge such transition is whether a liquid drop contacts the base of a roughness groove. It is expected that, after the contact, liquid immediately fills the roughness groove, and subsequently the wetting state is changed from Cassie-Baxter state to that of …
Thermal Design Of Lithium Bromide-Water Solution Vapour Absorption Cooling System For Indirect Evaporative Cooling For It Pod,
2014
University of Texas at Arlington
Thermal Design Of Lithium Bromide-Water Solution Vapour Absorption Cooling System For Indirect Evaporative Cooling For It Pod, Digvijay Ramkrishna Sawant
Mechanical and Aerospace Engineering Theses - Archive
Supervising Professor: Dereje Agonafer Nowadays with increase use of internet, mobile there is increase in heat which ultimately increases the efficient cooling system of server room or IT POD. Use of traditional ways of cooling system has ultimately increased CO? emission and depletion of CFC's are serious environmental issues which led scientific people to improve cooling techniques and eliminate use of CFC's. To reduce dependency on fossil fuels and 4environmental friendly system needed to be design. For being utilizing low grade energy source such as solar collector and reducing dependency on fossil fuel vapour absorption cooling system has shown a …
Finite Element Based Methodology For Prediction Of Matrix-Dominated Failure In Composites,
2014
University of Texas at Arlington
Finite Element Based Methodology For Prediction Of Matrix-Dominated Failure In Composites, Guillaume Seon
Mechanical and Aerospace Engineering Dissertations - Archive
The objective of this work is to develop a computational failure prognosis methodology applicable to virtual testing of composites. The major motivation for the establishment of virtual testing is the ability to reduce actual testing of composite structures, which is oftentimes expensive and time consuming, by numerical simulations. A successful virtual test methodology should be applicable to monotonic and fatigue loading, account for strong anisotropy of composite materials and capture the effects of manufacturing irregularities. This work proposes to use three-dimensional finite element modelling for predicting the onset and progression of matrix-dominated failures modes, such as matrix cracks and delaminations, …
Improving Ducting To Increase Cooling Performance Of High-End Web Servers Subjected To Signicant Thermal Shadowing -An Experimental And Computational Study,
2014
University of Texas at Arlington
Improving Ducting To Increase Cooling Performance Of High-End Web Servers Subjected To Signicant Thermal Shadowing -An Experimental And Computational Study, Divya Mani
Mechanical and Aerospace Engineering Theses - Archive
Ensuring that all the critical components like CPU's receive sufficient amount of flow as per their requirement is an vital importance in implementing air cooling for IT equipments. In addition to that the overall system resistance varies with the component location with in the chassis. In this study, parametric improvement in chassis ducting system is made to counteract the effects of thermal shadowing in a open compute air cooled server in which a CPU thermally shadows the other. Commercially available computational fluid dynamics codes have permitted simulation of server models to predict efficiency of the servers with every changes made …
Analytical And Experimental Investigation Of Thermal Transport In Three-Dimensional Integrated Circuits (3d Ics),
2014
University of Texas at Arlington
Analytical And Experimental Investigation Of Thermal Transport In Three-Dimensional Integrated Circuits (3d Ics), Leila Choobineh
Mechanical and Aerospace Engineering Dissertations - Archive
Thermal management of three-dimensional integrated circuits (3D ICs) is recognized to be one of the foremost technological and research challenges currently blocking the widespread adoption of this promising technology. The computation of steady-state temperature fields in a 3D IC is critical for determining the thermal characteristics of a 3D IC and for evaluating any candidate thermal management technology. An analytical solution for the three-dimensional temperature field in a 3D IC based on solution of the governing energy equations using Fourier series expansion for steady-state temperature fields is studied. Comparison of the predicted temperature fields with finite-element simulation shows excellent agreement. …
Effect Of Warm Water Cooling For An Isolated Hybrid Liquid Cooled Server,
2014
University of Texas at Arlington
Effect Of Warm Water Cooling For An Isolated Hybrid Liquid Cooled Server, Alekhya Addagatla
Mechanical and Aerospace Engineering Theses - Archive
Data center cooling strategies have changed overtime due to increases in power densities and ever increasing server cooling power requirement. Traditionally, most data centers adopt air cooling where the Computer Room Air Conditioning (CRAC) units pump volumes of chilled air to cool information technology (IT) equipment and dispose the heat from the servers to the ambient. With demand for energy-efficient and cost-effective data centers growing, alternative methods to both provide electrical power and cooling systems are the subject of active investigation. As data centers increase in size and current air-cooling systems reach their limitations, cooling technology will inevitably evolve towards …
A New Multiscale Approach For Dynamic Modeling And Simulation Of Micro-Nano Biomolecular Systems Characterized By A Low Reynolds Number,
2014
University of Texas at Arlington
A New Multiscale Approach For Dynamic Modeling And Simulation Of Micro-Nano Biomolecular Systems Characterized By A Low Reynolds Number, Mahdi Haghshenas-Jaryani
Mechanical and Aerospace Engineering Dissertations - Archive
In this dissertation, a new multiscale computational framework was developed in order to model and simulate motility of micro-nano-sized objects in fluid environments, characterized with a low Reynolds number. Especially, it has been used for studying the dynamic behavior of biomolecular systems such as motor proteins inside cells.Long simulation run time is one of the most important issues in modeling of cellular and biomolecular systems at the nanoscale due to the multiple time and length scales involved in the dynamics of these systems. These multiscale features are caused by either structure-structure (e.g. flexibility in biological structure or contact) or structure-fluid …
Factors Affecting The Performance Characteristics Of Wet Cooling Pads For Data Center Applications,
2014
University of Texas at Arlington
Factors Affecting The Performance Characteristics Of Wet Cooling Pads For Data Center Applications, Vishnu Sreeram
Mechanical and Aerospace Engineering Theses - Archive
The energy consumption of data centers in the current US market is fast growing in large numbers by every day. It was reported that in 2013, US data centers almost consumed 91 billion kilowatt-hours of electricity significant enough to power the whole of New York city twice a year [1]. Ever since the explosion of cloud computing, digital content and others the energy consumed by data centers has taken a steep increase and will continue in the coming years.As a result, there is a growing need to reduce the energy consumption of data centers by employing different cooling techniques which …
Experimental And Computational Study Of An It Pod And Its Cooling System,
2014
University of Texas at Arlington
Experimental And Computational Study Of An It Pod And Its Cooling System, Suhas Sathyanarayan
Mechanical and Aerospace Engineering Theses - Archive
Conventional data centers are extremely large buildings that have complex power distribution and cooling systems. These data centers employ relatively expensive cooling systems which are inefficient. These inefficiencies of traditional data centers can be overcome by partitioning the server load into modular sections which can be deployed, powered and cooled depending on availability and requirement. Modular data centers are increasingly being developed instead of using large data centers to save huge amount of capital investment. High energy efficiency is a priority and measures have been taken to increase it. Cooling techniques such as air-side economization and evaporative cooling are proving …
