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Mechanical and Aerospace Engineering Theses - Archive

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Full-Text Articles in Mechanical Engineering

Considerations For Generating Accurate Linear Transfer Functions For Laminar Flow Transmission Line Dynamics, Sina Jasteh Jan 2015

Considerations For Generating Accurate Linear Transfer Functions For Laminar Flow Transmission Line Dynamics, Sina Jasteh

Mechanical and Aerospace Engineering Theses - Archive

Modeling fluid lines for applications such as hydraulic fracturing has been studied for many years, and we know that the inverse frequency method presents very accurate solutions for systems with lines in almost all laminar flow cases. However, utilizing this method is not easy for all users, and requires experience and understanding of the method. In this study a simplified method is introduced for accurately modeling the transients in lines which requires minimum experience in utilizing inverse frequency methods; the accuracy and limits of this simplified method are studied. Also, alternative approaches are presented which improved the accuracy of the …


Optimal Design Of A Parallel Beam System With Elastic Supports To Minimize Flexural Response To Harmonic Loading, Bret R. Hauser Jan 2015

Optimal Design Of A Parallel Beam System With Elastic Supports To Minimize Flexural Response To Harmonic Loading, Bret R. Hauser

Mechanical and Aerospace Engineering Theses - Archive

Mechanical systems subject to vibration are prevalent across many industries. Harmonic problems can be especially challenging to optimize due to the likelihood that the response will be multi-modal; influenced by system natural frequencies throughout the design space. Further, analysis of these systems often involves large and complex computer models which require significant resources to execute. A parallel beam system, as evaluated with Finite Element Modeling (FEM), is used as an example in this work to demonstrate a proposed method of identifying an optimum in a constrained, multi-modal response environment with consideration for Expensive Black Box Functions. The presented method leverages …


Effects Of Transverse Shear Deformation On Composite Beams With Various Laminate Configurations And Boundary Conditions, Wei-Tsen Lu Jan 2015

Effects Of Transverse Shear Deformation On Composite Beams With Various Laminate Configurations And Boundary Conditions, Wei-Tsen Lu

Mechanical and Aerospace Engineering Theses - Archive

Analytical methods are developed for determining deflection of composite beams under transverse load with various boundary conditions and laminate configurations. The present methods include development of expression for 1-D equivalent bending stiffness with and without presence of twisting curvature and prediction of the beam deflection accounting for transverse shear effect. Finite element analysis of 3-D ANSYS models is conducted by using Solid186 elements. The present analytical model is executed by using MATLAB program. Both analytical and FEM models were first validated by using isotropic material in the model and comparing the existing solutions. The composite beams with rectangular cross-section and …


Reduced-Order Analysis Of Dual Mode Supersonic Combustion Ramjet Propulsion System, Vijay Gopal Jan 2015

Reduced-Order Analysis Of Dual Mode Supersonic Combustion Ramjet Propulsion System, Vijay Gopal

Mechanical and Aerospace Engineering Theses - Archive

High speed propulsion systems typically possess relatively simple geometry but the complexity involved in the flow characteristics makes their analysis a challenging task. The current research work introduces a reduced order analytical model for a steady operation of dual mode SCRamjet (Supersonic Combustion Ramjet) propulsion system at design and off-design conditions. The model hopes to reduce analysis time and complexity to carry out parametric sweep studies for preliminary design of SCRamjet engines. The analytical model splits the analysis of SCRamjet engine into five interactive components namely: inlet, isolator, injector, burner and nozzle. Each component is modelled using physics of gas-dynamics …


Viscoelastic Effects On A Polyetherimide Cylinder With Constant Radial Deformation, Louis Edward Parkman Jan 2015

Viscoelastic Effects On A Polyetherimide Cylinder With Constant Radial Deformation, Louis Edward Parkman

Mechanical and Aerospace Engineering Theses - Archive

The relaxation of an axisymmetric radially crimped joint is analyzed with the inner component being formed from the engineering grade polymer ULTEMTM 1000 polyetherimide. Creep and Relaxation tests were performed at several temperatures in order to use Time Temperature Superposition theory to assemble a master curve for predictions at long times based on short time testing. The master curves for each test were fit to the appropriate Prony Series and all coefficients are tabulated for re-use. The elastic theory for the classic thick walled cylinder was reviewed and the conversion from elasticity to viscoelasticity was demonstrated. Strength predictions are …


Development Of A Numerical Tool To Study The Mixing Phenomenon Occurring During Mode One Operation Of A Multi-Mode Ejector-Augmented Pulsed Detonation Rocket Engine, Joshua Dawson Jan 2015

Development Of A Numerical Tool To Study The Mixing Phenomenon Occurring During Mode One Operation Of A Multi-Mode Ejector-Augmented Pulsed Detonation Rocket Engine, Joshua Dawson

Mechanical and Aerospace Engineering Theses - Archive

A novel multi-mode implementation of a pulsed detonation engine, put forth by Wilson et al. [2], consists of four modes; each specifically designed to capitalize on flow features unique to the various flow regimes. This design enables the propulsion system to generate thrust through the entire flow regime. The multi-mode ejectoraugmented pulsed detonation rocket engine operates in mode one during take-o_ conditions through the acceleration to supersonic speeds. Once the mixing chamber internal flow exceeds supersonic speed, the propulsion system transitions to mode two. While operating in mode two, supersonic air is compressed in the mixing chamber by an upstream …


Use Of A Windbreaker To Mitigate High Speed Wind Loading On A Modular Data Center, Prasad Pramod Revankar Jan 2015

Use Of A Windbreaker To Mitigate High Speed Wind Loading On A Modular Data Center, Prasad Pramod Revankar

Mechanical and Aerospace Engineering Theses - Archive

The data centers that are located in open regions are subjected to various environmental risks. Earthquakes and very strong winds have the greatest effect on the structural integrity of the data centers. As the wind blows against the external structure, there is a buildup of pressure against the external structure which is translated to the supporting structure. Certain components of the data center like the inlet and exhaust dampers cannot withstand high wind speeds. Various kinds of fences have been used as windbreakers to prevent wind induced damage to objects. A windbreaker basically acts as a barrier to the upstream …


The Configurator: A Novel Approach To Enterprise Configuration Of Complex Software Systems, Thomas K. Wang Jan 2015

The Configurator: A Novel Approach To Enterprise Configuration Of Complex Software Systems, Thomas K. Wang

Mechanical and Aerospace Engineering Theses - Archive

Software systems are ubiquitous within aerospace technology. They are essentially the guidance, navigation, and control (GNC) of aircraft and satellites. Software systems are a primary component of satellite ground control systems, as well. Similarly, radar systems heavily utilize software systems. The design of aerospace software systems presents challenges outside of traditional aerospace or computer science domains. Mission operability and design constraints are balancing factors critical to the implementation phase of ground control software systems. Therefore, design decisions can often complicate the system architecture. Complexities within the architecture inevitably lead to challenges in the system integration phase. Numerous software source code …


Performance Evaluation Of Compliant Foil Seal, Sashidhar Raghuraman Jan 2015

Performance Evaluation Of Compliant Foil Seal, Sashidhar Raghuraman

Mechanical and Aerospace Engineering Theses - Archive

The concept of foil bearings has gained large acceptance in the industry and is been applied for various rotating equipment including air cycle machines, cryogenic turbo-expanders, centrifugal compressors and gas turbine engines. The ever-increasing demand for maintenance free and durable components has led to the development of compliant foil seals (CFS). Labyrinth and Brush seals have been widely employed for reducing the leakage flow at high pressure and temperature conditions, to enhance the overall performance of the system. Increase in the radial clearance to compensate the lack of their capability to accommodate the higher rotor orbits results in more leakage. …


Design And Structural Of A Fence Used For Protecting Modular Data Center From High Speed Wind, Nikhil Baviskar Jan 2015

Design And Structural Of A Fence Used For Protecting Modular Data Center From High Speed Wind, Nikhil Baviskar

Mechanical and Aerospace Engineering Theses - Archive

Various data centers built in an open area are occasionally susceptible to different kinds of natural calamities. Wind, either from any of the sources like hurricane, tornado or storm is one of those ecological dangers with high speed flow. These high speed winds can be responsible for downed power lines, trees and collapsing of buildings as well, the wind may adversely impact a data center’s structure. Windbreaker or wind fence is basically used to reduce the high speed of the wind resulting in the protection of structures or objects behind it. Some modular data centers which encounter problems of high …


Sustainable Methodology For The Use Of Fuel Cells In Data Centers, Vignesh Balasubramanian Jan 2015

Sustainable Methodology For The Use Of Fuel Cells In Data Centers, Vignesh Balasubramanian

Mechanical and Aerospace Engineering Theses - Archive

Data centers have become the lynchpin of the modern economy - from the small to medium-sized organizations, to the enterprise data centers that operates American corporations and the server farms that operate cloud-computing services accommodated by Facebook, Amazon, Google, and others. The booming of cloud storage, extensive data analysis, e-commerce, and internet traffic is also making data centers one of the rapidly growing clients of electricity in developing countries, and one of the key drivers in the construction of new power plants. Key researches are carried out for sustainable development of power usage in data centers. Fuel cells have gone …


Semi-Active Suspension System Using A Magnetorheological Damper, Abinav Suresh Jan 2015

Semi-Active Suspension System Using A Magnetorheological Damper, Abinav Suresh

Mechanical and Aerospace Engineering Theses - Archive

Magnetorheological (MR) Fluid changes its yield strength when it is subjected to a magnetic field. When this fluid is used inside a damper, it has the ability to change the damping coefficients when it is acted upon by magnetic fields. In this experiment, a MR damper was tested on a shock dyno, where characteristics of the damper was found. Three parameters were changed during the course of the experiment, namely: electric current supplied through the solenoid of the damper, displacement amplitude of the piston and driving frequency of the motor. The results show that there was an increase in damping …


Development Of Alkali Chlorides As Heat Transfer Fluids With Addition Of Nanoparticles, Sriram Sambasivam Jan 2015

Development Of Alkali Chlorides As Heat Transfer Fluids With Addition Of Nanoparticles, Sriram Sambasivam

Mechanical and Aerospace Engineering Theses - Archive

Recent studies have shown that using a single fluid for Heat Transfer and Thermal Energy Storage, improves the working and efficiency of a CSP. It improves the conversion efficiency (thermal energy to electrical) and also reduce the thermal losses due to heat exchangers by eliminating them. Other methods of storage are thermo chemical TES or phase change TES, but they require heat exchanger between HTF and TES medium, due to which the thermal losses between them are significant. CSP works on a conventional thermodynamic cycle (Rankine Cycle, Brayton Cycle) indicating that higher operating temperature are required to achieve higher efficiency. …


Dynamics And Control Of The Smart Maintenance And Inspection Robotic Free-Flyer (Smirff), Ameya Rajendra Godbole Jan 2015

Dynamics And Control Of The Smart Maintenance And Inspection Robotic Free-Flyer (Smirff), Ameya Rajendra Godbole

Mechanical and Aerospace Engineering Theses - Archive

The aim of the future space missions would be exploring near earth planets and asteroids. This would mean longer flight durations requiring a space habitat. Longer flight durations would require frequent maintenance and repairs of the space habitat. This would involve the risk of exposing astronauts to the harsh environments while conducting extra-vehicular activities. This risk can be minimised by using a tele-operated free- flying robot. Free- flying robots are a unique class of robots which do not have rigid fixed base and oat in space. A concept of Smart Maintenance Inspection and Robotic Free- flyer (SMIRFF) is presented in …


Analysis Of A Composite Beam With Unsymmetrical C Crossection, Martin M. Kora Jan 2015

Analysis Of A Composite Beam With Unsymmetrical C Crossection, Martin M. Kora

Mechanical and Aerospace Engineering Theses - Archive

The research work focuses on analysis of composite beam, where a closed form analytical solution was developed to determine the sectional properties of composite beam with unsymmetrical C cross section. The sectional properties such as centroid, equivalent axial stiffness and equivalent bending stiffness are computed. A parametric study of shear center and centroid with different layup sequences was conducted using the developed solution. The ply stresses developed in the C beam is also calculated analytically and is verified by finite element analysis. The result from the proposed theory gives excellent agreement with the ANSYS™


Test And Evaluation Of An Inlet Barrier Filter To Increase Engine Time-On-Wing For The Bell Boeing V-22 Osprey Tiltrotor, Victor Hwa Jan 2015

Test And Evaluation Of An Inlet Barrier Filter To Increase Engine Time-On-Wing For The Bell Boeing V-22 Osprey Tiltrotor, Victor Hwa

Mechanical and Aerospace Engineering Theses - Archive

The Bell Boeing V-22 Osprey Tiltrotor has seen significant deployment to austere environments where airborne sand and dust is generated due to aircraft operation on, or near, the ground. Current V-22 production aircraft are equipped with an engine air particle separator (EAPS) to remove larger particles of sand and dust, but finer particulates remain an issue for engine combustion air. A prototype engine inlet barrier filter (EIBF) has been developed as a more robust particle filtration solution. Inlet air filtration with the prototype EIBF is expected to quadruple engine time-on-wing by preventing nearly all fine particulates from entering the engine. …


Manufacturing And Characterization Of Ultra Light Bio-Inspired Nanocomposite Structures, Sushma Pothana Jan 2015

Manufacturing And Characterization Of Ultra Light Bio-Inspired Nanocomposite Structures, Sushma Pothana

Mechanical and Aerospace Engineering Theses - Archive

The inner part of bones is spongy cell-type three dimensional structure called cancellous bone which is the major contributor in keeping the bone weight very low. Yet, bone can sustain body weight and reasonable impact loads implying bone is a naturally optimized light-weight but strong structure. This study demonstrates a novel approach to manufacture bone-like nanocomposite structure for weight saving structural applications. For this, Silicon Carbide (SiC )nano particles are dispersed in SC-15 epoxy resin (a two part liquid resin that solidifies when mixed together at room temperature). Using our novel 3D+ manufacturing technique we developed lighter but stronger nanocomposite …


Experimental And Simulation Board Level Reliability Assessment Of Wafer Level Chip Scale Packages (Wcsps) Under Thermal Cycling, Hassaan Ahmad Khan Jan 2015

Experimental And Simulation Board Level Reliability Assessment Of Wafer Level Chip Scale Packages (Wcsps) Under Thermal Cycling, Hassaan Ahmad Khan

Mechanical and Aerospace Engineering Theses - Archive

Various studies have been conducted to study the effect of varying board thickness on thermo-mechanical reliability of BGA packages. Wafer level chip scale packages (WLCSP) have also been studied in this regard to determine the effect of PCB build-up thickness on the solder joint reliability. The studies clearly demonstrate that the thinner Printed Circuit Boards (PCBs) result in longer thermo-mechanical fatigue life of solder joints. Due to an extensive research, literature and past trends to support the theory that thinner PCBs perform better than thicker ones, Texas Instruments (TI) opted to move forward by decreasing the thickness of their PCBs …


Efficient Method To Cool The Data Center Using Solar Energy, Krishna Desai Jan 2015

Efficient Method To Cool The Data Center Using Solar Energy, Krishna Desai

Mechanical and Aerospace Engineering Theses - Archive

Solar energy is the only source which is abundantly available and which can beused to power a cooling system that is based on absorption cycle.Solar cooling system can be used to provide refrigeration for food and medicinesand comfort cooling also. Such systems are specifically applicable to the large applications having large cooling loads for particularly big periods of a year. Peak demandfor the cooling of a building and the highest availability of solar radiation are in similar phase, which makes solar cooling of any building a potential energy source andalso a green solution.In this project, The Lithium bromide-water absorption cycle …


Analytical Modeling Of Helium Turbomachinery Using Fortran 77, Purushotham Balaji Jan 2015

Analytical Modeling Of Helium Turbomachinery Using Fortran 77, Purushotham Balaji

Mechanical and Aerospace Engineering Theses - Archive

Advanced Generation IV modular reactors, including Very High Temperature Reactors (VHTRs), utilize helium as the working fluid, with a potential for high efficiency power production utilizing helium turbomachinery. Helium is chemically inert and nonradioactive which makes the gas ideal for a nuclear power-plant environment where radioactive leaks are a high concern. These properties of helium gas helps to increase the safety features as well as to decrease the aging process of plant components.The lack of sufficient helium turbomachinery data has made it difficult to study the vital role played by the gas turbine components of these VHTR powered cycles. Therefore, …


Design And Cfd Analysis Of The Intake Manifold For The Honda Cbr250rr Engine, Subhash Seshadri Jan 2015

Design And Cfd Analysis Of The Intake Manifold For The Honda Cbr250rr Engine, Subhash Seshadri

Mechanical and Aerospace Engineering Theses - Archive

The scope of this project is to improve reliability issues on a turbocharged Honda CBR250RR engine and boost the performance by redesigning the intake manifold - one of the key components of this engine package. The engine has been used in the past by the UTA Formula SAE team in several open-wheeled race cars providing a light weight platform with a high power to weight ratio. Previous intake manifolds did not provide balanced distribution of air flow among all cylinders. This lead to incorrect air/fuel ratios were some cylinders ran too lean at times, while others were running too rich. …


Numerical Investigation Of Steady State And Transient Thermal Performance Of A Multi-Chip Vapor Chamber, Mohammad Parhizi Jan 2015

Numerical Investigation Of Steady State And Transient Thermal Performance Of A Multi-Chip Vapor Chamber, Mohammad Parhizi

Mechanical and Aerospace Engineering Theses - Archive

Effective dissipation of heat generated in microelectronic devices during operation is critical for reliability and performance, particularly for advanced architectures such as microserver chips. Vapor chambers are a class of heat spreaders that have received much recent attention due to their passive nature and superior heat spreading capability. Several studies have investigated thermal performance of vapor chambers as heat spreading devices. However, developing a simple and accurate model which could be easily used in industry is still a big challenge. Moreover, more work needs to be done to optimize the performance of vapor chambers. For instance, developing a vapor chamber …


Developing A 7mmx7mm Qfn Package Using Liquid Crystal Polymer, Mitul H. Naik Jan 2015

Developing A 7mmx7mm Qfn Package Using Liquid Crystal Polymer, Mitul H. Naik

Mechanical and Aerospace Engineering Theses - Archive

Quad Flat No-Lead (QFN) packages are one of the most widely used and popular packages in the industry. The QFN packages gained popularity in the last decade because of its excellent electrical/thermal characteristics and lower costs. QFN packages are widely used in automotive, defense, handheld devices where space is a constraint and high current circuits require the package is mounted on thick printed circuit boards. This work makes an attempt to develop an economical 7mm*7mm QFN package using Liquid Crystal Polymer (LCP).The first challenge in this work investigate the different grades of LCP to match the electrical as well as …


Fluid-Crack Interaction In Hydraulic Fracturing, Harshil Vora Jan 2015

Fluid-Crack Interaction In Hydraulic Fracturing, Harshil Vora

Mechanical and Aerospace Engineering Theses - Archive

Hydraulic fracturing has been one of the major improvements in petroleum engineering in the past few decades. Since then this process has been used progressively and over million wells have been fracked using hydraulic fracturing technology. A thorough understanding of the formation of fracture network and its propagation is essential to keep evolving the technology. In the present study, the Linear Elastic Fracture Mechanics (LEFM) approach is applied to the crack propagation to understand the fluid crack interaction in brittle rocks under hydraulic loading. The boundary element method (BEM) is used to carry out the numerical analysis. Additionally, an explicit …


Design And Optimization Of Under Tray For Formula Sae Race Car Using Cfd Analysis, Girish Bangalore Jalappa Jan 2015

Design And Optimization Of Under Tray For Formula Sae Race Car Using Cfd Analysis, Girish Bangalore Jalappa

Mechanical and Aerospace Engineering Theses - Archive

With the advent of inverted wings to produce down-force in Formula-1 during the 1960's, aerodynamics has played a big role in increasing the vehicle performance. An aerodynamics system consists of front, rear wings and an under-tray. This thesis focuses on design of a new under-tray using CFD analysis for a Formula-SAE car.


Simulation Of Indeterminate Multiple, Simultaneous Impact And Contact For A Flexible Multibody System, Rohit Vijay Katti Jan 2015

Simulation Of Indeterminate Multiple, Simultaneous Impact And Contact For A Flexible Multibody System, Rohit Vijay Katti

Mechanical and Aerospace Engineering Theses - Archive

This work presents a method for understanding the impact behaviour of a flexible body undergoing multiple, simultaneous contacts. A continuous model is used with an event-driven function in MATLAB, which detects the collisions. The flexible body is defined as a system of particles, having inter-particle forces in terms of spring, damper coefficients. Equations of motion for such a Flexible MultiBody system are determined and then solved for different phases.In the method presented, the indeterminate nature of equations of motion encountered, during impact, and contact for flexible body are examined. Constraint forces are determined during the different phases of an impact …


Nanoscale Toughening Mechanisms Of Ultra High Temperature Novel Hfb2 Based Multiphase Ceramics, Zoher Shabbir Lavangia Jan 2015

Nanoscale Toughening Mechanisms Of Ultra High Temperature Novel Hfb2 Based Multiphase Ceramics, Zoher Shabbir Lavangia

Mechanical and Aerospace Engineering Theses - Archive

During return of spacecraft they endure very high temperatures (3000°F), few materials can withstand temperatures this high along with additional loads of the spacecraft. Reinforced carbon-carbon (RCC) material system is used as Thermal Protection System (TPS) which is made of laminated graphite rayon-phenolic epoxy, which need to sustain extreme heat. However, these materials are very prone to premature degradation due to oxidation. Silicon Carbide (SiC) and Hafnium Diboride (HfB2) are candidate materials for TPS but, they inherently lack the required toughness for such applications. This research is carried out in two stages, first is to study the individual properties of …


Computational Analysis Of I.T. Rack Under Vibration Load, Framroz Meheryar Bharucha Jan 2015

Computational Analysis Of I.T. Rack Under Vibration Load, Framroz Meheryar Bharucha

Mechanical and Aerospace Engineering Theses - Archive

Structural failure of a rack due to vibration could result in injury to people, damage to IT equipment, or interruption of services that depend on proper functioning of the IT and networking equipment in the rack. In this topic, a computational study of an IT rack and a group of racks placed adjacent to each other under three vibration load scenarios: transportation, office and earthquake vibration is presented.Each rack can weigh as much as 1600 kg (3500 lb.) when fully populated with IT equipment. Two standards commonly used for testing racks with synthetic seismic loads are the GR-63-CORE Network Equipment …


Performance Analysis Of A Helium Cooled Vhtr Powered Brayton Cycle Topping Unit On An Existing Steam Cycle Using Numerical Propulsion System Simulation, Warren Romao Caetano Freitas Jan 2015

Performance Analysis Of A Helium Cooled Vhtr Powered Brayton Cycle Topping Unit On An Existing Steam Cycle Using Numerical Propulsion System Simulation, Warren Romao Caetano Freitas

Mechanical and Aerospace Engineering Theses - Archive

With the decommissioning of ageing coal power plants due to outdated technology and high levels of air pollution, the advantages of overhauling existing infrastructure is twofold. First, by providing an alternate, sustainable fuel source, like nuclear power, the problem of air pollution can be brought to check. Second, utilizing existing steam plant infrastructure reduces initial investment costs and allows investors to keep the existing steam plant running until the new infrastructure is ready to go online.The focus of this research is to design and analyze the topping cycle required to support an existing 300 MW power plant based on the …


Quantifying Air Flow Rate Through A Server In An Operational Data Center And Assessing The Impact Of Using Theoretical Fan Curve, Neha Shigrekar Jan 2015

Quantifying Air Flow Rate Through A Server In An Operational Data Center And Assessing The Impact Of Using Theoretical Fan Curve, Neha Shigrekar

Mechanical and Aerospace Engineering Theses - Archive

Cooling is one of the major cost factors in data centres that accounts for 37% of the total data centre electricity consumption. Demands on cooling systems have increased substantially in recent years, due to increasing server densities. To avoid the overheating of servers, cooling aisles are over provisioned, but little attention is paid to the actual scenario at the server level. Cooling requirements of the servers is calculated on the basis of fan manufacturer’s published data for the air flow capacity of the server fan and system impedance data obtained from the server designer put together. Thus, the air flow …