Digital Commons Network^™

Modeling The Feasibility Of Corn Stover Combustion As A Heat Source At Corn Ethanol Plants, Sulekha Tamvada

Theses and Dissertations

Alternative energy sources are of prime interest for most of the nations across the world. Rising fuel prices and depleting petroleum reserves are of serious national and global concern. Bio-fuels if proved feasible for larger scale implementation could become the ideal breakthrough in easing the extensive dependence on fossil fuels and retaining the current engine technology of fossil fuels. Current methods of producing bio-fuels rely heavily on the consumption of non-renewable energy in the production process. Therefore, it is desirable to find renewable alternatives to these non-renewable energy sources.

Although bio-mass based fuels have been tested and proven to be …

Pressure Field Estimation Using Particle Image Velocimetry, Jean O. Calzada

Theses and Dissertations

In recent years, scientist and engineers have shown the advantages created by using the Particle Image Velocimetry (PIV) method as flow diagnostic tool to characterize instantaneous velocity fields. One of the important benefits is found on its non-intrusive nature, this leads to accurate velocity fields. From the velocity field obtained by PIV important quantities can be derived, such as pressure and vorticity. The present study, uses PIV data of an incompressible turbulent pulsed jet to determine the pressure field associated with the flow field. The pressure is calculated by using the averaged velocity field along with three different fundamental equation: …

Modeling The Residual Useful Life Of Railroad Bearing Grease, Thania Alejandra Martinez

Theses and Dissertations

Railroad bearing performance is often constrained by the life of its lubricant. The lubricant life is determined by tribomechanical processes that are present during bearing operation. No known physical models exist to predict the railroad bearing lubricant life. This thesis summarizes the efforts undertaken in the development of empirical models that can accurately predict the residual useful life of railroad bearing grease. Modeling techniques to be employed include regression, regression trees, and split plots. The grease samples used to populate this model come from healthy and faulty bearings that were run under different loads, speeds, and ambient conditions in a …

Structural Optimization Using Parametric Programming Method, Krupakaran Ravichandraan

All Theses

The Parametric Programming method is investigated to consider its applicability to structural optimization problems. It is used to solve optimization problems that have design variables as implicit functions of some independent input parameter(s). It provides optimal solutions as a parametric function of the input parameter(s) for the entire parameter space of interest. It does not require the detailed discrete optimizations needed at a large number of parameter values as in traditional non-parametric optimization. Parametric programming is widely used in optimal controls, model predictive control, scheduling, process synthesis and material design under uncertainty due to the above mentioned benefits. Its benefits …

Evaluation Of Two-Phase Evaporation Pressure Drop Correlations For Low Refrigerant Mass Flux., Anna Fenko

Electronic Theses and Dissertations

This study was conducted to evaluate three currently popular two-phase pressure drop models for extremely low velocity refrigerant flow through smooth circular evaporators in household refrigeration systems. Experimental data was taken at mass fluxes under 70 kg/m²s for two refrigerants, R134A and R600A, internal diameters of aluminum evaporators ranging from 0.186 to 0.317 inches, U-bend internal radii ranging from 0.342 to 0.750 inches in horizontal and vertical orientations of evaporators. The geometry of the samples closely resembled a commonly used serpentine shape with multiple U-bends experiencing both, up- and down-flow of the refrigerant. Two empirical models, Müller-Steinhagen & …

Application Of The Aeroacoustic Analogy To A Shrouded, Subsonic, Radial Fan., Bryan Buccieri

Electronic Theses and Dissertations

A study was conducted to investigate the predictive capability of computational aeroacoustics with respect to a shrouded, subsonic, radial fan. A three dimensional unsteady fluid dynamics simulation was conducted to produce aerodynamic data used as the acoustic source for an aeroacoustics simulation. Two acoustic models were developed: one modeling the forces on the rotating fan blades as a set of rotating dipoles located at the center of mass of each fan blade and one modeling the forces on the stationary fan shroud as a field of distributed stationary dipoles. Predicted acoustic response was compared to experimental data. The blade source …

Industrial Energy Consumption, Benchmarking, And Analysis In The United States, Daniel Maldonado

Mechanical Engineering Undergraduate Honors Theses

The purpose of this paper is to analyze the energy consumption of the industrial sector in the United States, and to identify the tools that can be used to minimize the consumption and improve the energy efficiency of all facilities in the country. The first part of the paper is a historical analysis of the industrial sector energy consumption, where the different energy sources are identified. The second part details different electronic tools that will provide facilities the ability of performing benchmarking, in order to understand their energy performance. Finally, the third part of this paper provides information about the …

A Look At Commercial Building Energy Use And Energy Efficiency Technologies From 1980 To Present, Marvin M. Arroyo

Mechanical Engineering Undergraduate Honors Theses

Energy consumption has increased considerably in the last fifty years as population rises. At the same time, design and efficiency of all equipment used in commercial buildings have changed as well. The purpose of this thesis is to explain how HVAC systems have changed and how they have affected energy consumption. Entities like the US Department of Energy (DOE) and the US Energy Information Administration (EIA) facilitate the data-gathering process by offering databases of energy information from actual monthly energy bills to promote public understanding of energy and its interaction with the economy and the environment. Moreover, in order to …

Multi-Level Optimal Design Using Game Theory With Model Updating By Low Discrepancy Sampling, Yanchen Xu

Theses and Dissertations

The Design of Experiment (DOE) based response surface methodology (RSM) is a commonly used technique for solving optimization problems. The traditional DOE method has some shortcomings when used to update the RSM model. This thesis aims to develop a new DOE technique to solve the model updating problems in design optimization. Toward this end, a new DOE based RSM method is proposed to solve this problem by using low-discrepancy sequence method to generate the additional data points needed to update the model to replace the traditional factor and level based DOE method.

Tested on a couple of numerical example problems, …

Implementing A Linear Quadratic Spacecraft Attitude Control System, Daniel Kolosa

Masters Theses

This thesis implements a linear quadratic attitude control system for a low-thrust spacecraft. The goal is to maintain spacecraft alignment with a time-varying thrust vector needed for trajectory change maneuvers. A linear quadratic attitude control approach is used to maintain spacecraft pointing throughout flight. This attitude control strategy uses the thrust-acceleration input obtained from a linear quadratic optimal trajectory control model that simulates the trajectory of a spacecraft in orbit maneuvers. This attitude model simulates a CubeSat, a small satellite that is equipped with a low-thrust propulsion and attitude control system. An orbit raising and a plane change scenario is …

Automatic Carrier Landing System For V/Stol Aircraft Using L1 Adaptive And Optimal Control, Shashank Hariharapura Ramesh

Mechanical and Aerospace Engineering Theses

This thesis presents a framework for developing automatic carrier landing systems for aircraft with vertical or short take-off and landing capability using two different control strategies - gain-scheduled linear optimal control, and L1 adaptive control. The carrier landing sequence of V/STOL aircraft involves large variations in dynamic pressure and aerodynamic coefficients arising because of the transition from aerodynamic-supported to jet-borne flight, descent to the touchdown altitude, and turns performed to align with the runway. Consequently, the dynamics of the aircraft exhibit a highly non-linear dynamical behavior with variations in flight conditions prior to touchdown. Therefore, the implication is the need …

Magnetic Field Enhanced Thermal Conductivity Analysis Of Magnetic Nanofluids, Christopher Allen

Mechanical and Aerospace Engineering Theses

The magnetic properties of four water-based nanofluids consisting of Al2O3, CuO, Fe3O4, and SiO2 were exploited to analyze the effect of the application of an external magnetic field on the thermal conductivity of the nanofluid. When the magnetic field is applied, the magnetic dipole moments of the particles align and the particles come in contact with each other and form chains in the direction of the applied magnetic field. When parallel to the direction of heat flow, the magnetic field causes the effective thermal conductivity in the direction of the magnetic field to increase. A higher thermally conductive fluid can …

A Model Analysis Of Sand Insertion In Hydraulic Fractures, Ya Hao

Mechanical and Aerospace Engineering Theses

Hydraulic fracturing (fracking) is a well-stimulation technology to create large volume of fracture formation in rocks for gas and/or oil extraction. This technology has been applied to commercially exploit natural gas in unconventional shale reservoirs that contain immense quantity but low density of hydrocarbon sources. The productivity can be largely dependent on the connectivity of fractures that must stay open. However, upon initial hydraulic fracturing, the fractures would be closed due to high hydrostatic pressure deep inside the crust. Sand must be pumped into the fractures to keep them open. An in-depth understanding of the sand distribution and its dependence …

Thermal Analysis Of Disk Brake In Order To Study The Brake Fluid Vaporization Phenomenon Of A Formula Sae Car, Anurag Dey

Mechanical and Aerospace Engineering Theses

The brake system is inarguable one of the most critical aspect of a vehicle safety. It has always been the major concern for design engineers to develop a system that gives a steady performance with respect to time. In order to achieve that feat, one of the most common problems that arises in maintaining a brake is the problem of brake fluid vaporization. Brake fluids, being hygroscopic in nature, absorb moisture over a period of time. It is one of the prime reasons for reducing the longevity of brake fluid volume inside the brake caliper as the boiling point of …

Estimation Of Fracture Mechanics Parameters In 3d Tsv Package During Chip Attachment Process, Mohammed Shahid Ali

Mechanical and Aerospace Engineering Theses

Nowadays, the packaging of electronic products is becoming revolutionized, since the packages are becoming more and more complex, dense, thinner and lighter for greater portability. Miniaturization of packages is being taken to the next level, and hence, 3D packaging has become a hot topic in the present research area. Three dimensional chips stacking with TSV technology has gained momentum to meet such requirements of significant miniaturization and power reduction which result in increased performance. However, the unique issues related to yield and reliability of critical areas in TSV based 3D ICs need to be evaluated. Therefore, Reliability of such electronic …

Smart Bed And Contact Impact Of Flexible Bodies Using Energy Compensation Method, Pranav Parikh

Mechanical and Aerospace Engineering Theses

This work investigates robotic means to prevent pressure ulcers in human bodies. The smart bed is intended to act as an intelligent assistant to a care-giver that relieves some of the physical and mental burden involved in preventing pressure ulcers. This type of device is needed because of a labor shortage in the nursing field. The smart bed distinguishes itself from the current available measures by redistributing pressure and minimizing shear forces acting on the skin in contact. This is done by using data from the sensor grid installed on the bed surface and actuating the degrees of freedom associated …

Developing And Validating Thermodynamic Models For Evaporative Cooling Employed In Data Centers, Niravkumar Prabhatsinh Dodia

Mechanical and Aerospace Engineering Theses

Cooling of Data centers is of paramount importance for continuous and reliable operation of Servers housed by them. Considerable amount of total power is used to drive the cooling activity. Various different types of cooling methods have been implemented and are currently operating in various data centers. Evaporative (Indirect/Direct) Cooling is trending these days because of its ability to provide cooling at minimal cost. Previous studies have presented various cooling plants in data centers and studied them. A dedicated model for Evaporative cooling is developed and validated. The data is computed assuming the developed cooling model operating at a particular …

Computational Analysis Of Enhancing Heat Transfer In A 3-D Stacked Die Using Different Finned Heat Sink, Deekshith Pittala

Mechanical and Aerospace Engineering Theses

3D die stacking is an exciting new technology that increases the transistor’s density by integrating two or more dies vertically with a dense high – speed interface. The result of 3D die stacking is a significant reduction of interconnect both within a die and across dies in a system. The objective of the thermal design requirement for a 3D stacked die package is to maintain the junction temperatures of the devices at or below specified limits. Installing the Heat sink aid the heat transfer activity from a package. The extent of cooling and the junction temperatures vary if the designs …

Cfd Modeling And Parametric Study Of Vapor Chamber As Heat Spreaders For High-Power Electronic Devices, Dhanraj Arun Patil

Mechanical and Aerospace Engineering Theses

Technological developments have resulted in a growing demand for high power electronic devices. Although these high power devices meet the high performance requirements, they also generate a very large amount of heat which adversely affects their operating efficiency. Most part of the heat within a package is generated at the chip and hence it is imperative to keep junction temperature as low as possible. This is commonly achieved by using heat sinks mounted directly on top of the package. Heat sinks provide a significant enhancement in cooling by increasing the surface area. However, base thickness of heat sinks limits its …

Experimental Study On Effects Of Segregated Cooling Provisioning On Thermal Performance Of Information Technology Servers In Air Cooled Data Centers, Ashwin Venugopal Siddarth

Mechanical and Aerospace Engineering Theses

Modern Information Technology (IT) equipment are typically assumed to operate in quiescent airflow conditions in an uncontained data center facility. In this study, the multi-scaled thermal management strategies are reconsidered at the IT chassis and rack level for a containment system. For an ideal containment configuration of airflow provisioning the entirety of conditioned air provided by the Computer Room Air Conditioning (CRAC) unit would flow through the IT equipment and return back to the CRAC. But in actuality a lack of interfaced airflow distribution exists between the amount of conditioned air provisioned to the rack and the volume capacity ingested …

Enhancement Of Fog-Collection Efficiency Of A Raschel Mesh Using Surface Coatings And Geometric Changes, Mithun Rajaram

Mechanical and Aerospace Engineering Theses

In a few countries, such as Chile, a Raschel mesh is widely used in the field to collect fog. In this work, we explored the possibility of enhancing fog-collection efficiency of a typical Raschel mesh through surface modification and geometric changes. We demonstrated about 100% enhancement in the fog-collection efficiency.

A Study On Evaporative Cooling For Data Centers & Artificial Neural Network Modeling, Pritam Karmokar

Mechanical and Aerospace Engineering Theses

This study mainly aims at exploring how, one of the best “Green” solutions for IT equipment cooling aka Evaporative Cooling, can be optimized for better future deployment. Also, this study focuses on ways to deploy Artificial Neural Network models to Dynamic Systems. Today, SERVERS are one of most important devices that our technology driven world cannot do without. Efficiently cooling these delicate yet highly power dense beasts, while being environment friendly is one of our prime concerns. This study is a combination of two deceptively divergent works. First, on exploring the workings of this technique by investigating one such Evaporative …

Development Of A Methodology And Sample Preparation To Evaluate Reliability Of Oil Cooled Data Center, Venkata Naga Indu Sravani Kota

Mechanical and Aerospace Engineering Theses

Liquid immersion cooling is not a new concept which is slowly emerging as an alternative solution to conventional chilled air cooling systems for data centers. The main idea is to build a body of knowledge to help industry make more informed regarding mechanical reliability of IT equipment in mineral oil immersed systems. The goal is to develop a testing procedure for evaluating the reliability of electronic packages and components when immersed in mineral oil. PCB’s, chip packages, passive components like capacitors, inductors, resistors, diodes, cables and wiring form the most important parts of a server used in data centers. The …

Experimental Analysis Validating A Control Scheme To Develop A Dynamic Cooling Solution For Non-Uniform High Powered Electronic Devices In Data Center, Ruturaj Kiran Kokate

Mechanical and Aerospace Engineering Theses

The trend towards higher heat fluxes and non-uniform power distribution continues as we follow Moore’s law with technology nodes now approaching 10nm. Cooling is always designed for maximum junction temperature and as such it is important to mitigate hot spots. All cold plates have a static design by nature and do not possess the capability to respond to non-uniform heat dissipation. The unique “dynamic cold plate” concept aims to improving on conventional static designs through implementation of sensing and control, by redistributing the liquid across its body to counter varying power dissipation across the device being cooled.

Additive Manufacturing And Stress Analysis Of Naturally And Artificially Optimized Celullar Structures, Sachin Jose

Mechanical and Aerospace Engineering Theses

The main objective of our research is to manufacture topology optimized cellular structures using 3D printing and polymer infusion and obtain their structural response. First, we have obtained topology optimized cellular structure of beam using an in-house topology optimization tool. The Solid Isotropic material with Penalization (SIMP) method of optimization is used for finding the optimal topology. Since we require a continuous structure where we can take advantage of additive manufacturing, a no-penalty approach was chosen. For 3D printing, first the optimized condition for manufacturing was determined. Important parameters on which manufacturing depend are Number of Shells, Infill percentage and …

Quantitative Evaluation Of A Thrust Vector Controlled Transport At The Conceptual Design Phase, Vincent Patrick Ricketts

Mechanical and Aerospace Engineering Theses

The impetus to innovate, to push the bounds and break the molds of evolutionary design trends, often comes from competition but sometimes requires catalytic political legislature. For this research endeavor, the ‘catalyzing legislation’ comes in response to the rise in cost of fossil fuels and the request put forth by NASA on aircraft manufacturers to show reduced aircraft fuel consumption of +60% within 30 years. This necessitates that novel technologies be considered to achieve these values of improved performance. One such technology is thrust vector control (TVC). The beneficial characteristic of thrust vector control technology applied to the traditional tail-aft …

Cae Analysis On A Ford Ecoboost Mustang Connecting Rod For Forged Steel, Aluminum 7075, Shiva Prasad Keralapura Basavaraju

Mechanical and Aerospace Engineering Theses

Connecting rod is high volume production critical component in an automobile engine. Every Internal combustion engine uses a connecting rod. Connecting rod must have highest possible rigidity with lowest possible weight. The major stress developed in the connecting rod are axial stress, due to combustion chamber pressure, and bending stress, due to centrifugal effect. Connecting rod mainly fails due to fatigue; according to survey, about 90% of the time the failure is due to fatigue. CAE analysis on Ford Eco boost Mustang connecting rod is carried out to validate the life of the connecting rod for forged steel and Aluminium7075. …

The Effect Of Material Strain Hardening On The Buckling Strength Of A Perforated Plate Under Uniaxial Loading, Mayuri Suresh Patil

Mechanical and Aerospace Engineering Theses

Plates or members containing plate elements have been used in the offshore, aerospace and construction industry. Cutouts are often located to lighten the weight of the structure, but these cutouts reduce the ultimate strength of the plate. A number of studies have taken place for determining the buckling strength of a perforated plated but few discuss the effect of material strain hardening on the buckling strength of a perforated plate. Buckling strength is often considered as an important criterial to determine the serviceable limit of the perforated plate in the offshore structure. The aim of the present study is to …

Two Phase Flow Cfd Analysis Of Refrigerants In A Condenser Pipe For Prediction Of Pressure Drop And Pumping Power, Aniket Ramchandra Kalambe

Mechanical and Aerospace Engineering Theses

With the ever growing need of achieving optimum cooling at chip level at the expense of low input pumping power and keeping in check the Global Warming Potential (GWP) & Ozone Depletion Potential (ODP) has given rise to “two-phase on chip cooling” with nature friendly refrigerants. Currently, “air-cooling” and “single-phase water on-chip cooling” using copper micro-channel coolers are being used but “two-phase on chip cooling” with refrigerants have a very large scale & long lasting advantages over the prior. However, due to the perceived complexity of modelling two-phase flow, this solution is not yet well understood. Modelling of two phase …

Additive Manufacturing Methodologies For Multi Process And Multi Material Scenarios, Tushar Saini

Mechanical and Aerospace Engineering Theses

Additive Manufacturing processes have been developing and continuously improving but are primarily constrained to single materials, albeit some commercial multi extrusion 3D printers do exist where by it is possible to print with multi-colored fluidic polymers or at most two filaments of the same type. 3D printing an object with volumetric varying properties requires manual modification of the G-Code, not a feasible option considering the average size of G-Code generated by the slicing software. This research focuses on developing a post processing methodology that modifies the large G-Code files generated by the slicing software according to user requirements. The proposed …