Mechanical Engineering Commons^™

Experimental And Numerical Study Of Heat Transfer Phenomenon In A Micro Droplet Reactor, Chintan Jitendra Gandhi

Mechanical and Aerospace Engineering Theses - Archive

Temperature is an important control parameter during chemical reaction process. Micro reactors have attracted much attention due to its capability of excellent heat and mass transfer, fast reaction, and inherent safety of small scale. Among various types of micro reactors, micro droplet as a batch reactor has its own advantages such as high multiplexing capability. However, strong heat dissipation characteristics of microscale systems (due to large surface to volume ratio) hampers the measurement and monitor of enthalpy changes during the reaction. This study mainly focuses on temperature monitoring at micro droplet reactor by using thin film resistance temperature detector (RTD). …

An Open Source App-Hardware Setup To Control The System For Data Center Cooling, Anay Satish Darekar

Mechanical and Aerospace Engineering Theses - Archive

Control systems for data center cooling exists in the proprietary form and are often sold as part of the overall unit. They provide vital information related to the cooling systems and supply information on the temperature and humidity conditions inside the data center. Since most of these control systems software are proprietary they are expensive and hence not accessible to all. This project aims to develop a control system that operates on similar lines, but is economical and easily available. Developing a desktop or mobile based application not only gives the end user control over the cooling method (ex. DEC …

Computational Study And Optimization Of Wet Cooling Media In Direct Evaporative Heat Exchanger, Tejas Vijay Bhongale

Mechanical and Aerospace Engineering Theses - Archive

Evaporative cooling media pads are the primary component of importance in direct evaporative cooling units. To increase the overall efficiency of direct evaporative cooling systems, a wet cooling media pad is considered for further optimization in design and operation. An installation technique called ‘staging’ of cooling media pads is examined and evaluated for its incremental cooling, water usage, and operational cooling efficiency. For Staging, a cooling media is divided into multiple vertical sections, and separate water distribution headers control each part. Staging of cooling media can reduce water consumption in data centers and potentially lessen the amount of cooling media …

Fabrication, Calibration And Characterization Of Micro-Scale Resistance Temperature Detectors, Kunjan Anilkumar Chaudhari

Mechanical and Aerospace Engineering Theses - Archive

Through this research, fabrication, calibration and characterization of micro-scale Resistance Temperature Detector (RTD) were studied. The RTD is meant to sense the temperature at the micro scale level on the hot spot of integrated circuit devices. Material that we focused in this study was indium tin oxide (ITO). Indium tin oxide thin films are widely used as an electrode owing to its optically transparent and electrical conducting properties. However, ITO thin film behavior as an RTD has not been well studied yet, which we aimed in this study. The commercially available ITO thin film deposited on a glass substrate was …

Fem Analysis Of Composite Stringers For An Airplane Fuselage, Akashsingh Birendrasingh Thakur

Mechanical and Aerospace Engineering Theses - Archive

With the advent of technology, materials have advanced many folds; One such technical revelation has been Fiber-reinforced Composite Materials. Composite materials have two major advantages, among many others: Improved strength and stiffness, especially compared to other materials on a unit weight basis. For example, Composite materials have stiffness comparable to the stiffness of steel but with a strength decimal order higher and more than three times lighter. These advantages have led to new aircraft and spacecraft designs that are radical departures from past efforts based on conventional materials. The stringers serve to take up(along with the skin) the compression and …

Solder Ball Reliability Assessment Of Wafer Level Chip Scale Package (Wlcsp) Through Power Cycling, Bhavna Conjeevaram

Mechanical and Aerospace Engineering Theses - Archive

Failure analysis and its effects are major reliability concerns in electronic packaging. More accurate fatigue life prediction can be obtained after the consideration of all affecting loads on the electronic devices. When an electronic device is turned OFF and then turned ON multiple times, it creates a loading condition called Power Cycling. The die is the main heat source causing non-uniform temperature distribution. The solder ball reliability assessment of wafer level chip scale package (WLCSP) is done through computational methods such as Finite element analysis. WLCSPs use wafer level package technology which is an extension of the Wafer Fab process, …

Computational Study Of Impact Of Thermal Shadowing In Non-Directed Flow For Air And Oil Cooled Servers. Form Factor Study And Customization Of Heat Sink For Data Center Application, Chinmay Hemantkumar Bhatt

Mechanical and Aerospace Engineering Theses - Archive

In today’s networking world, the usage of Servers and Data centers has been increasing significantly with a corresponding increase in power. The data center energy efficiency largely depends on thermal management of servers. Currently, air cooling is the most widely used thermal management technology in data centers. However, air cooling is starting to reach its limits due to high powered microprocessors and packaging. To overcome these limitations of air cooling in data centers, liquid cooling methods are starting to gain more traction. Thermal shadowing is the effect in which temperature of a cooling medium increases by carrying heat from one …

Static And Dynamic Fea Analysis Of A Composite Leaf Spring, Himanshu Arun Raut

Mechanical and Aerospace Engineering Theses - Archive

Composite materials are widely used in aeronautical, marine and automotive industries, because of their excellent mechanical properties, low density and ease of manufacture. Due to this increasing trend to utilize composite materials, it has become necessary to investigate the pros and cons of composites. This research investigated the static and dynamic behaviors for a composite leaf spring that are used in Chevrolet Corvette Grand and light tractor-trailers. The objective of this study was to find the cause of de-lamination/ failure of the unidirectional composite layers in varying cross sections of the leaf spring. Finite element method is used to calculate …

Numerical Investigation Of Vortex Generators And Jet In Cross-Flow Enhancements, Aditya Raman

Mechanical and Aerospace Engineering Dissertations - Archive

Vortex generators have extensively been used over the past few decades for heat transfer applications. Their passive form of enhancement coupled with the ease of their implementation is the primary reason for their growing popularity. The streamwise counter rotating vortex pair (CVP) that is formed downstream of these vortex generators act as a source of energy that can set up stirring scales to enhance heat transfer and improve mixing. The CVP can be used to energize the boundary layer in the case of wall bounded flows, and as a consequence vortex generators have also been used to delay flow separation. …

Computational Design And Flow Analysis Of Smart Flow Control Device For Dynamic Cold Plate Used In Computer Server Cooling, Sruthi Errukula

Mechanical and Aerospace Engineering Theses - Archive

One of the areas which Electronics cooling research is focusing on is high heat fluxes and non-uniform power distribution. Cooling is always required for maximum junction temperature and as such it is important to mitigate hot spots. These hot spots result in large temperature differences across the surface of high-end devices such as multi-core chip scale packages. One possible solution for non-uniform power distribution across the chip can be use of dynamic cold plate cooling along with smart flow control device and thus this project aims at developing and testing of dynamic cold plate integrated with use of smart flow …

Fiber Bragg Grating (Fbg) Sensors For The Simultaneous Measurements Of Strain And Temperature, Abhay Kumar Singh

Mechanical and Aerospace Engineering Theses - Archive

This research presents a single fiber Bragg grating (FBG) sensor that is capable of measuring the axial load and temperature simultaneously. The FBG sensor is coated with a block of recrystallized Lophine, which introduces the bandwidth modulation of the FBG reflectance spectrum. Thermal-mechanical testing of the Lophine-coated FBG sensor under different load and temperature combinations was carried out. It was discovered that the FBG bandwidth is linearly proportional to the applied load and temperature. By fitting the measured FBG bandwidths and central Bragg wavelengths as linear functions of the axial load and temperature, we demonstrated that the axial load and …

Effect Of Viscoelastic Modeling Of Pcb On The Board Level Reliability Of Wafer Chip Scale Package (Wcsp) In Comparison To Orthotropic Linear Elastic Modeling, Avinash Anaskure

Mechanical and Aerospace Engineering Theses - Archive

The assessment of board level solder joint reliability during thermal cycling is very important for electronic packages. During thermal cycling, the mismatch in Coefficient of Thermal Expansion (CTE) between the materials used in the package induces stress on the solder interconnects and result in deformation stresses. Finite element tools are widely used for rapid design optimization and also for understanding board level reliability issues. Lumped board properties approach, explicit geometry approach, and ECAD approach are the three widely used approaches for creating models for PCBs. In the lumped board properties approach, orthotropic elastic material properties are assigned to PCBs. However, …

Effect Of Manufacturing-Induced Defects And Orientation On The Failure And Fracture Mechanism Of 3d Printed Structures, Amit Khatri

Mechanical and Aerospace Engineering Theses - Archive

Additive manufacturing is a rapidly growing cutting edge technology. Number of experimental studies have shown that strength of product manufactured by additive Fused Deposition Method (FDM) is influenced by different processing parameters involved during manufacturing. This thesis work presents experimental and theoretical investigation of mechanical behavior of ABS material fabricated with variation in some of process parameters such as Axis Orientations, Raster Orientation, Infill Percentage, Layer Height and Number of Shells. Different experiments were designed to understand the basics of 3D printing manufacturing and to characterize the mechanical behavior of 3D printed structures. This study helps to understand, how different …

Design Of Flow Control Device For Dynamic Cold Plate And Optimization Of Servers To Decrease Junction Temperature Of Heat Sinks, Kunal Atulkumar Shah

Mechanical and Aerospace Engineering Theses - Archive

Electronics cooling research is facing the challenges of high heat flux removal and increased pumping power. Not much attention has been focused related to server and module level cooling. The continued increase in heat fluxes at the chip level due to new and robust technology nodes following Moore’s law is starting to push the limits of air cooling and especially for high end servers. An alternative to air cooling is liquid (water and oil immersed) cooling. The optimized dynamic cold plates that use water as the cooling fluid have shown over 28 % and 52% of reduction in pumping power …

Analysis Of Composite Plates By Using Mechanics Of Structure Genome And Comparison With Ansys, Banghua Zhao

Open Access Theses

Motivated by a recently discovered concept, Structure Genome (SG) which is defined as the smallest mathematical building block of a structure, a new approach named Mechanics of Structure Genome (MSG) to model and analyze composite plates is introduced. MSG is implemented in a general-purpose code named SwiftComp™, which provides the constitutive models needed in structural analysis by homogenization and pointwise local fields by dehomogenization. To improve the user friendliness of SwiftComp™, a simple graphic user interface (GUI) based on ANSYS Mechanical APDL platform, called ANSYS-SwiftComp GUI is developed, which provides a convenient way to create some common SG models or …

Free Edge Stress Analysis Of Laminated Structures With Arbitrary Cross Sections Using Mechanics Of Structure Genome, Lingxuan Zhou

Open Access Theses

Composite laminates have been increasingly used in advanced structural applications, due to their excellent strength-to-weight properties and considerable flexibility on designing with respect to the laminate layup. However, the heterogeneity and anisotropy of composite laminates have brought many challenges for analysis and numerous researches have been devoted in this field. A well known problem which has been studied intensively is the so-called free-edge problem. It states that due to the mismatch in elastic properties of adjacent layers, full-scale three-dimensional (3D) and highly concentrated stress fields will occur in the vicinity of the free edges. The interlaminar stresses grow very rapidly …

Modeling Methods For Merging Computational And Experimental Aerodynamic Pressure Data, Jacob Courtney Haderlie

Open Access Dissertations

This research describes a process to model surface pressure data sets as a function of wing geometry from computational and wind tunnel sources and then merge them into a single predicted value. The described merging process will enable engineers to integrate these data sets with the goal of utilizing the advantages of each data source while overcoming the limitations of both; this provides a single, combined data set to support analysis and design. The main challenge with this process is accurately representing each data source everywhere on the wing. Additionally, this effort demonstrates methods to model wind tunnel pressure data …

A Genetic Algorithm Incorporating Design Choice For The Preliminary Design Of Unmanned Aerial Vehicles, Kenneth Michael Mull

Masters Theses

Unmanned Aerial Vehicles (UAVs) are currently at the forefront of aerospace technologies. The design of these aircraft is complex and often performance characteristics are coupled to multiple design attributes. At the early design phase both discrete and continuous design choices are present limiting the feasibility of traditional derivative based optimization techniques. In place of these methods, the design space can be explored using a genetic algorithm that mimics the process of natural selection, providing a capable and reliable base airframe constructed from the required performance metrics. By incorporating a genetic multidisciplinary optimization algorithm early in the conceptual design phase, aircraft …

Modeling, Optimizing And Testing Thermoelectric Generators For Liquid-To-Liquid Low Grade Waste Heat Recovery, Ali Eyddan Hamil

Masters Theses

The use of thermoelectric generators (TEGs) for producing electricity from low grade waste heat is thought to be a great solution in the future to reduce the power generation cost because of their advantages of reliability and environmental friendliness. Therefore, the current project aims to study thermoelectric generators for low grade waste heat recovery. In this work, a single unit cell of liquid to liquid thermoelectric generator attached with heat exchangers (heat sinks) is modeled using an internal flow. Its optimum design is obtained based on heat sink optimization and the optimal design method. An analytical model of four unit …

Analytical Study Of Miniature Thermoelectric Device, Mohammed Dhannoon

Masters Theses

Miniature thermoelectric devices (TE) have been regarded as hopeful devices to attain efficient cooling in microprocessors and other small-scale devices. To recognize the performances of miniature thermoelectric coolers, a thermoelectric cooling module is theoretically analyzed. Particular attention is paid to the impact of the thermoelectric element length effect and the substrate material type influence on the cooling performance. The electrical contact resistance and thermal contact are taken into account.

Furthermore, miniature thermoelectric is compared with large thermoelectric, and effective material properties of miniature thermoelectric are studied. The obtained results also demonstrate power density (cooling/heating power per unit area of the …

A Robotic Device To Assist With In-Vivo Measurement Of Human Pelvic Organ Tissue Properties, Shashank S. Kumat

Mechanical and Aerospace Engineering Theses - Archive

Measurement of the biomechanical properties of human pelvic organ tissue without undergoing minimally invasive surgery is desired for diagnostics purposes and take precautionary actions if needed. The biomechanical properties of the bladder change with age and due to diseases. Thus, identification of the viscoelastic properties of the tissue could help in detecting early stages of the disease in the bladder. A literature survey revealed that no device exists that could be used to characterize the biomechanical properties of the human bladder in-vivo. This research contributes towards the development of a diagnostic system that could be used in a medical setting …

The Influence Of Functional Weights On The Performance Of Least Squares Finite Element Formulation On Hybrid Meshes, Anirudh Rajagopal

Mechanical and Aerospace Engineering Theses - Archive

The Least-Squares Finite Element Method (LSFEM) is a numerical method for solving partial differential equations (PDE) approximately by minimizing the L-2 norm of the PDE residuals. Unlike the more common Galerkin approach, this method does not employ integration by parts to reduce the continuity requirements of the basis functions. Instead, the PDE is cast as a first-order system of differential equations, which allows for the solution of primary and secondary variables with the same order of accuracy. In addition, this approach always leads to a direct minimization problem and therefore not subject to the restrictive inf-sup condition and does not …

Application Of Artificial Neural Network For Evaporative Cooling In Data Centres, Feyisola Adejokun

Mechanical and Aerospace Engineering Theses - Archive

A data center is a facility that may be used to house telecommunication or storage devices. Because of the 24/7 required operation of a data center, large segments of a data center are geared towards evacuating heat generated from operating one. Data centers entail multiple operating configurations, great amount of constraints and nonlinear correlations. The need to effectively optimize a data center operation presents a daunting challenge. The data center considered in this research is a test bed modular data center (MDC). Comprising of an Information Technology (IT), DEC and IEC module. Typical MDC are dynamic and complex in nature …

Shape Optimization Of Helical Coil Tube For Maximizing Heat Transfer, Venkat Manoj Kandukuri

Mechanical and Aerospace Engineering Theses - Archive

Many researchers have observed the enhancement of heat transfer in coiled tubes compared to straight tubes with the same diameter and length. It is known fact, that in a helical coil tube the maximum axial velocity shifted towards the outer wall of the pipe and imbalance between centrifugal forces and inertial loads to a secondary motion of the fluid in the cross-section of the tube. This secondary motion is responsible for improved transport of heat energy to/from the tube walls. Previous conducted Experimental and computational parametric studies show the relationship between the increased heat transfer and parameters such as pitch, …

Self-Transport Of Liquid Drops Through A Functional Mesh For Removing Sweat Away From Skin, Manasvikumar Oza

Mechanical and Aerospace Engineering Theses - Archive

In this work, a functional mesh is developed to transport liquid drops from one side of the mesh to the other. A theoretical model is established, which has been used to obtain three design criteria. Based on these design criteria, functional meshes have been generated and tested with commercially available sponge attached to the mesh. Finally, such a mesh is demonstrated to be effective to remove sweat from human skin. As an application of this research, the concept of this functional mesh solves existing problems with a sport wear. The current sport wear is capable of absorbing sweat, but not …

Thermal Stress Analysis Of Unidirectional Composite Material By Fem Modeling, Gopal D. Gulwani

Mechanical and Aerospace Engineering Theses - Archive

Micromechanics of composite is study of complex mechanism of stress and strain transfer between fiber and matrix within a composite as well as distributions of physical fields inside heterogeneous medium. It was used successfully in predicting accurately physical properties like effective stiffness, effective linear thermal expansion of heterogeneous materials like composite. However, when it comes to strength characteristics of composite especially in transversal direction it failed to predict more accurate results. This thesis is focused on thermally induced stress analysis of unidirectional composite by finite element method. Thermal stresses which are dangerously ignored factor in mechanics of composite usually occur …

Formation Flight For Fuel Saving In Coronet Missions Of Kc-135r And F-15c/E, Christopher Allen Kniffin

Mechanical and Aerospace Engineering Theses - Archive

The fuel saving benefit of formation flight has been demonstrated through theoretical and computational analyses, simulation, wind tunnel and flight tests. When an aircraft flies in a specific region in the wake of another aircraft, it experiences upwash, which results in reduced drag and thus reduced thrust requirement. One specific USAF mission that can potentially benefit from formation flight is coronet missions. In a coronet mission, fighter aircraft are escorted and refueled, as needed, by tanker aircraft over a long range. During the flight, the receiver aircraft fly in formation with the tanker but outside of the wake of the …

Experimental Characterization And Simulation Of Carbon Nanotube Strain Sensing Films, Nagendra Krishna Chaitanya Tummalapalli

Masters Theses

Carbon Nanotubes (CNTs) have excellent mechanical, electrical and electromechanical properties. These properties led to a lot of novel applications. Due to change in electrical properties under mechanical loading, these composites have potential applications in strain sensors, when these are fabricated as films. CNT-based films are commonly fabricated using different physical and chemical techniques based on the property requirements governing those applications. In this work, CNT films were prepared using wet chemical based methods and chemical vapor deposition techniques.

Plasma chemical vapor deposition using microwave power is used in the first method to deposit films on silicon substrates, using Nickel film …

Analytical Modeling And Numerical Simulation Of A Thermoelectric Generator Including Contact Resistances, Shripad Dhoopagunta

Masters Theses

With increasing demand for energy harvesting systems, research has been conducted in different areas in which Thermoelectric Generators (TEG) find their way into the top of many available resources. Out of many energy harvesting systems available, TEGs are comparatively easier to study, to manufacture and also to comprehend while producing enough energy for applications they find use in. They are solid state devices, meaning; they do not have any moving parts and hence makes them durable. Most of the energy that goes out of the automobile as exhaust is reused to power the TEGs. In most of the works that’s …

Optimization Methodology For Cvt Ratio Scheduling With Consideration Of Both Engine And Cvt Efficiency, Steven Beuerle

Masters Theses

A transmission ratio schedule is developed to optimize the fuel consumption for an automotive continuously variable transmission (CVT) connected to an internal combustion engine (ICE). Although the optimal operating line (OOL) generated from an engine brake specific fuel consumption (BSFC) map can be used to generate a CVT ratio schedule that yields maximum engine efficiency, it was found that OOL-based CVT ratio scheduling does not necessarily offer the best fuel economy because optimal CVT efficiency does not always correspond to OOL tracking. To develop a CVT ratio schedule that can offer the best fuel economy, a novel ratio-scheduling methodology is …