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Mechanical and Aerospace Engineering Theses - Archive

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Articles 151 - 180 of 677

Full-Text Articles in Mechanical Engineering

Trust Based Time-Varying Network Topology For Distributed Co-Operative Control Of Multi-Class Multi-Agent Systems, Ankur Vipulkumar Dalal May 2018

Trust Based Time-Varying Network Topology For Distributed Co-Operative Control Of Multi-Class Multi-Agent Systems, Ankur Vipulkumar Dalal

Mechanical and Aerospace Engineering Theses - Archive

With increased levels of autonomy in most of the engineering fields and booms in areas such as swarms, platoons and Internet of Things (IoT), communication and information flow has become a highly researched field. With advancements in autonomous vehicles (AVs) and drones in armed warfare, more and more focus is being laid on intercommunication between these vehicles and its surroundings as well as intra-communication among the fleets/swarms itself. It is easier to deal with individual agents whereas it is quite challenging to deal with multi-agent systems especially with highly dynamic agents. In this thesis, we propose a general protocol for …


Dynamics And Control Of Jumping Legged Robot, Gurashish Singh May 2018

Dynamics And Control Of Jumping Legged Robot, Gurashish Singh

Mechanical and Aerospace Engineering Theses - Archive

This research aims to studying the agility of legged robots particularly their interactions with the ground and achieve a jumping motion by using an operational space controller. Methods were developed to first formulate the equations of motions of the full system. Then we used the published impact and contact analytical framework to detect simultaneous, indeterminate impact and transition to contact with friction and addressed the well-known issues with energy consistency when using rigid body models for dynamic systems (i.e. there are no unusual gains in the energy after impact has ended). Non-penetration of the ground was achieved through online constraint …


Characterization Of A Cold Plate By Experimental Analysis And Power Savings Calculation Of Dynamic Cold Plate, Barath Ragul Manimaran May 2018

Characterization Of A Cold Plate By Experimental Analysis And Power Savings Calculation Of Dynamic Cold Plate, Barath Ragul Manimaran

Mechanical and Aerospace Engineering Theses - Archive

Cooling is a critical part of data center’s infrastructure, and with ongoing demands in data processing and storage, thermal management issues are of great concern. Some imperative methods of removing heat are either using air or liquid (preferably water or refrigerant). When high power densities modules are involved, liquid cooling addresses some of the problems faced by air cooling as liquid coolants have higher thermal capacitance. Also, in the case of multi-chip modules, a non-uniform heating due to multicore generates hotspots and increases temperature gradients across the module. A dynamic cold plate was developed to address these issues with the …


Monitoring Calcification In Rigid Wet Cooling Media Used In Direct Evaporative Cooling Of Data Centers., Hemanth Narayan Dakshinamurthy May 2018

Monitoring Calcification In Rigid Wet Cooling Media Used In Direct Evaporative Cooling Of Data Centers., Hemanth Narayan Dakshinamurthy

Mechanical and Aerospace Engineering Theses - Archive

Rigid wet cooling media is a key component of direct and indirect evaporative cooling systems. Evaporation is the process of a substance in a liquid state changing to a gaseous state. When water evaporates only H2O molecules gets evaporated and the other chemicals in the water is left behind on the surface as residue. Soul concentration is to determine how calcium scale affects the overall performance i.e. saturation efficiency and pressure drop across the media pad. An Accelerated Degradation Testing by rapid wetting and drying on the media pads at elevated levels of calcium was planned on the media pad. …


Thermal Degradation Of Passive Components For Use In Single Phase Immersion Cooling Application, Keerthivasan Padmanaban May 2018

Thermal Degradation Of Passive Components For Use In Single Phase Immersion Cooling Application, Keerthivasan Padmanaban

Mechanical and Aerospace Engineering Theses - Archive

The growth in the computing and data industry demands high-performance data centers where the thermal management issues are of greater concern. A cooling system paradigm using the immersion cooling technology is a more reliable and effective method. In immersion cooling, servers are directly submerged into a dielectric fluid. A comparative study on the reliability of the passive components cooled by air, mineral oil and EC-100 was carried out. The Accelerated Thermal Cycling test based on ATC JEDEC is applicable only for air cooling. The ASTM standards D 3455 with some suitable modification was adopted to test the material compatibility with …


Measurement Of The Thermal Performance Of A Single-Phase Immersion Cooled Server At Elevated Temperatures For Prolonged Time, Pratik Vithoba Bansode May 2018

Measurement Of The Thermal Performance Of A Single-Phase Immersion Cooled Server At Elevated Temperatures For Prolonged Time, Pratik Vithoba Bansode

Mechanical and Aerospace Engineering Theses - Archive

Fully immersion of servers in electrically non-conductive (dielectric) fluid has recently become a promising technique for minimizing cooling energy consumption in data centers. The improved thermal properties of these dielectric fluids facilitate considerable savings in both upfront and operating cost over traditional air-cooling. This technology provides an opportunity for accommodating increased power densities. It also minimizes and addresses the common operational issues of air cooling methods like overheating and temperature swing in the system, fan failures, dust, air quality, and corrosion. This paper presents various data about the performance of a fully single-phase dielectric fluid immersed server over wide temperature …


Computational Fluid Dynamics Simulation-Based Artificial Neural Network Modelling For Data Center Cooling Prediction, Nikita Ravindra Sukthankar May 2018

Computational Fluid Dynamics Simulation-Based Artificial Neural Network Modelling For Data Center Cooling Prediction, Nikita Ravindra Sukthankar

Mechanical and Aerospace Engineering Theses - Archive

Continuous provision of quality supply air to data center’s IT pod room is key parameter in assuring effective data center operation without any down time. Due to number of possible operating conditions and non-linear relations between operating parameters make the working mechanism of data center difficult to optimize energy use. At present industries are using computational fluid dynamics (CFD) to simulate thermal behaviour for all types of operating conditions. The focus of this study is to predict Supply Air Temperature using Artificial Neural Network(ANN) which can overcome limitations of CFD such as high cost, need of expertise and large computation …


Cfd Analysis Of Thermal Shadowing And Optimization Of Heat Sinks In 3rd Generation Open Compute Server For Single Phase Immersion Cooling Applications, Ravya Dandamudi May 2018

Cfd Analysis Of Thermal Shadowing And Optimization Of Heat Sinks In 3rd Generation Open Compute Server For Single Phase Immersion Cooling Applications, Ravya Dandamudi

Mechanical and Aerospace Engineering Theses - Archive

In today’s networking world, utilization of servers and data center has been increasing significantly. Increasing demands of processing and storage of data causes corresponding increase in power density of servers. 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 very high-powered microprocessors and packaging. To overcome the limitations of air cooling in data centers, operators are moving towards immersion cooling using different dielectric fluids. Thermal shadowing is the effect in which temperature …


Analysis And Comparison Between A Conventional Metal And A Metal-Composite Marine Propeller Shaft, Kaushal Mayankkumar Shah May 2018

Analysis And Comparison Between A Conventional Metal And A Metal-Composite Marine Propeller Shaft, Kaushal Mayankkumar Shah

Mechanical and Aerospace Engineering Theses - Archive

The basic principal of a ship propulsion is the reactive (thrust) force generated by the propellers against the stream of water which forces the ship to propel in the opposite direction. The Shafting system is thus required to transmit the necessary torque to the propeller at a certain speed. Studies have suggested that shafts are the most common reason of failures among the whole marine propulsion system comprising of the main engine and propeller apart from the shaft. Stress concentration and torsional vibrations are the two major causes of failure in the propulsion shafting systems based on the case study …


Comparison Of Steel And Composite Leaf Springs Using Fea, Prashik Sunil Gaikwad May 2018

Comparison Of Steel And Composite Leaf Springs Using Fea, Prashik Sunil Gaikwad

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. Increasing competition and innovation in automobile sector tends to modify the existing products by new and advanced material products. A suspension system of vehicle is also an area where these innovations are carried out regularly. Leaf springs are one of the oldest suspension components that are being still used widely in automobiles. They contribute to 15-20% …


Experimental Analysis Of The Effects Of Single-Phase Immersion Cooling Of Optical Interconnects On Mechanical Properties Of Active Optical Cables, Hrishabh Singh May 2018

Experimental Analysis Of The Effects Of Single-Phase Immersion Cooling Of Optical Interconnects On Mechanical Properties Of Active Optical Cables, Hrishabh Singh

Mechanical and Aerospace Engineering Theses - Archive

Active optical cables (AOC) are being increasingly adopted for data communication and storage, networking, and high-performance computing (HPC) applications. However, their ability to meet higher data-rate requirements necessitates increased heat dissipation demands in fiberoptic datacom systems. Many dielectric coolants having heat capacities much higher than that of air are available in the market. However, there is a lack of literature and data on the reliability of using single-phase dielectric fluids for immersion-cooling of inter and intra-rack optical interconnections in data centers. Industry standards and prevalent aging test methods for optical cables prove insufficient as they do not address immersion in …


Design And Optimization Of Mixed Ionic-Electronic Conductive Material For Use In Solid Oxide Fuel Cell Utilizing Carbon Nanotubes, Shiuan Duo Chiang May 2018

Design And Optimization Of Mixed Ionic-Electronic Conductive Material For Use In Solid Oxide Fuel Cell Utilizing Carbon Nanotubes, Shiuan Duo Chiang

Mechanical and Aerospace Engineering Theses - Archive

Triple phase boundary (TPB) is considered to be an important limiting factor of the fuel cell performance. Triple phase boundary is a geometrical line where the ionic, electronic and gaseous fuel phase of the fuel cell comes in contact. Electrochemical reactions of the fuel cell occur at the TPB sites. The TPB length greatly impacts the efficiency of the fuel cells. Carbon nanotubes have recently been shown to enhance oxygen reduction reaction (ORR) of the fuel cell and transfer electrons with its conductive properties. CNT also provides porosity in the electrode and could facilitate mass transport. CNT allows for oxygen …


Finite Element Analysis And Design Improvement Of Aerospace Composite Hinges, Gaurang Girish Sonpal May 2018

Finite Element Analysis And Design Improvement Of Aerospace Composite Hinges, Gaurang Girish Sonpal

Mechanical and Aerospace Engineering Theses - Archive

Hinges are the most commonly used mechanical bearings to connect 2 objects for relative rotational motion. Modern day aerospace hinges are generally made using either Aluminum, Steel or bronze. The study analyzes the use of composite material as an alternative to traditional materials for manufacturing these hinges. The research is focused on the Finite element Analysis of a composite hinge as well as an aluminum hinge. The load capacity of both the types of hinges are compared. To improve the design of the composite hinge, a combination of composite material and aluminum is used to model a hybrid hinge design. …


General Methods For The Thermal Design Of Data Centers Based On Evaporative Cooling, Raghvendra Parinam May 2018

General Methods For The Thermal Design Of Data Centers Based On Evaporative Cooling, Raghvendra Parinam

Mechanical and Aerospace Engineering Theses - Archive

With the increasing load on the servers, the cost and energy required to cool a data center has been on the rise. This has kept the researchers to explore more efficient and economical cooling technologies for data centers. One such technology is evaporative cooling. The evaporative cooling systems are one of the most effective methods available for cooling the data centers. So, developing the generic methods for the thermal design of data centers is of utmost importance. This research aims to identify, develop and validate the thermal model for Direct Evaporative Cooling and Indirect Evaporative Cooling. By taking the environmental …


Psychrometric Bin Analysis For Data Center Cooling Modes Using Artificial Neural Networks, Abhishek Uday Walekar May 2018

Psychrometric Bin Analysis For Data Center Cooling Modes Using Artificial Neural Networks, Abhishek Uday Walekar

Mechanical and Aerospace Engineering Theses - Archive

With an increase in the need for energy efficient data centers, a lot of research is being done to increase the use of Air Side Economizers (ASEs), Direct Evaporative Cooling (DEC), Indirect Evaporative Cooling (IEC) and multistage I/DEC cooling. The cooling strategies used to control these systems is based on typical meteorological year (TMY) weather data and thermodynamic principles. But the main drawback of these control strategies is that they do not account for the nonlinearities developed by the conditions inside the data center. So, the primary objective of this study is to use Artificial Neural Networks (ANN) for predicting …


Comparison Of Cross-Sectional Profiles For Side Impact Crash Structure In Passenger Vehicle, Nitish Sharma May 2018

Comparison Of Cross-Sectional Profiles For Side Impact Crash Structure In Passenger Vehicle, Nitish Sharma

Mechanical and Aerospace Engineering Theses - Archive

Car’s safety is most important structural criteria while designing an automotive chassis. To protect the occupants from a direct impact, the passenger cabin and the structure of the vehicle should have an appropriate stiffness so that the it absorbs any kind of impact and keeps the passenger safe. Design standards are set by various vehicle safety association around the world based on different crash situations i.e. front crash, side impact, roll over etc. Among these standards, side impact crash account for over all 40% crashes all around the world and is one of the most fatal crash scenarios. This research …


On The Development Of A Human Thumb Tracking Device For Telemanipulation, Abdul Hafiz Abdul Rahaman May 2018

On The Development Of A Human Thumb Tracking Device For Telemanipulation, Abdul Hafiz Abdul Rahaman

Mechanical and Aerospace Engineering Theses - Archive

The human thumb is the first digit of the hand and influences the grasping capability of the human hand. Based on literature, most sensor gloves available capture the motion of the fingers, however, they lack the ability to capture the motion of the thumb. This research focuses on developing a methodology and associated hardware to capture the complex joint motion of the thumb and map it to an in-house developed multi-degree of freedom robotic thumb. A sensor device was developed to measure four joint angles of the human thumb, namely three flexion/extension (flex/ext) joint angles of carpometacarpal (CMC), metacarpophalangeal (MCP), …


Fea Of Carbon Composite As A Substitute For Steel (A992) In Case Of Square Or Rectangular Hollow Cross-Sections As Beams And Columns, Pradeep Ganesh Pai May 2018

Fea Of Carbon Composite As A Substitute For Steel (A992) In Case Of Square Or Rectangular Hollow Cross-Sections As Beams And Columns, Pradeep Ganesh Pai

Mechanical and Aerospace Engineering Theses - Archive

Improvement to an existing design is an ongoing and never-ending process in every field. The improvement can be in a myriad of areas like an increase in strength, reduction in weight, stiffness to a loading condition and so on. The way it is achieved can range from changing the properties of the material used by incorporating various manufacturing processes or by using an alternative material which can sustain the same loading conditions or for that matter, work better than the existing material. Composite materials like Carbon Fiber, Glass Fiber or Kevlar Fiber reinforced plastics, to name few, are being used …


Stochastic Finite Element Thermal Analysis Of A Ball Grid Array Package, Rahul Upreti May 2018

Stochastic Finite Element Thermal Analysis Of A Ball Grid Array Package, Rahul Upreti

Mechanical and Aerospace Engineering Theses - Archive

This study provides an insight into the factors which have a major impact on the probability of failure of a Ball Grid Array package. A stochastic finite element analysis was done on the package using First-order reliability method (FORM). The effects of uncertainty in material thermal conductivities, heat source, heat transfer coefficient and ambient temperature were studied. The average temperature at the die-junction interface was selected as failure criterion because the excess temperature at the junction is often a cause of failure. The performance of Finite Difference Method(FDM) and Semi-Analytic Complex Variable Method(SACVM) in computing sensitivities are compared. Results show …


Air Flow Pattern And Path Flow Simulation Of Airborne Particulate Contaminants In A Cold-Aisle Containment High-Density Data Center Utilizing Airside Economization, Gautham Thirunavakkarasu May 2018

Air Flow Pattern And Path Flow Simulation Of Airborne Particulate Contaminants In A Cold-Aisle Containment High-Density Data Center Utilizing Airside Economization, Gautham Thirunavakkarasu

Mechanical and Aerospace Engineering Theses - Archive

The energy used by Information Technology Equipment (ITE) and the supporting data center equipment keeps rising as data center expansion continues worldwide. To contain the rising operation costs, data center administrators are resorting to cost cutting measures by not adhering to the ambient data center environment standards. In many cases, free cooling techniques are adopted to partially or completely relieve the usage of refrigeration units, which adds to huge cost savings but also allows for the increased risk of particulate and gaseous contaminations. The ASHRAE TC9.9 subcommittee, on Mission Critical Facilities, Data Centers, Technology Spaces, and Electronic Equipment, has provided …


The Performance Of Quadrilateral Element With Rotational Degrees Of Freedom In Statics And Dynamics Analysis And Optimization, Xingzhi Wang May 2018

The Performance Of Quadrilateral Element With Rotational Degrees Of Freedom In Statics And Dynamics Analysis And Optimization, Xingzhi Wang

Mechanical and Aerospace Engineering Theses - Archive

Finite Element Method (FEM) is widely used in structural analysis, and the standard approach to increase the accuracy of analysis is increasing the total degrees of freedom (DOFs), namely, refine the mesh. By introducing the rotational DOFs, better accuracy can be achieved without change the mesh. The objective of this study was to investigate the performance of elements with rotational DOFs in statics and dynamics analysis and applying these elements to optimization. The implementation of three representative elements with rotational DOFs for statics analysis is reproduced. Also, this work implements these elements to dynamics analysis and optimization. The results show …


Computational Study Of Form Factor Of 3rd Generation Open Compute Servers Using Different Dielectric Fluids For Single-Phase Immersion Cooling, Pranavi Rachamreddy May 2018

Computational Study Of Form Factor Of 3rd Generation Open Compute Servers Using Different Dielectric Fluids For Single-Phase Immersion Cooling, Pranavi Rachamreddy

Mechanical and Aerospace Engineering Theses - Archive

Computer system dependency has been increased in the modern world and that has encouraged the rapid growth of data centers in leading business units like banking, education, transportation, social media and many more. Data center is a facility that incorporates an organisation’s IT operations and equipment, as well as where it stores, processes, and manages the data. To fulfil the demands of data storage and data processing, corresponding increase in power density of servers are needed. The data center energy efficiency largely depends on the thermal management of servers. Currently, air cooling is the most widely used thermal management technique …


Robust Predictive Analytics For Determining Acclimation Parameter Of It Equipment, Premsanth Sadasivam May 2018

Robust Predictive Analytics For Determining Acclimation Parameter Of It Equipment, Premsanth Sadasivam

Mechanical and Aerospace Engineering Theses - Archive

Acclimation is the process in which an IT equipment adjusts to a change in its environment such as a change in temperature and humidity, allowing it to maintain performance across a range of environmental conditions. In commissioning of a new cold shipped IT equipment in data centers, environmental acclimation is an important step. Proper acclimation also minimizes the risk of powering on a machine that may still be wet due to moisture condensation. An experimental study is carried out to find how the acclimation occurs and the factors influencing it. These experiments are designed with various temperature ranges and using …


Numerical Study Of Droplet Evaporation, Ritul Gandhi Dec 2017

Numerical Study Of Droplet Evaporation, Ritul Gandhi

Mechanical and Aerospace Engineering Theses - Archive

Droplet evaporation plays a vital role in various engineering fields such as air/fuel premixing, inkjet printing and many more. The high rate of power dissipation from the integrated circuits and chips of electronic devices creates a need for cooling it to achieve their optimal functionality. The high rate of cooling can be achieved by thin film evaporation of water by phase change as compared to the air cooling methods. Therefore, the study of droplet evaporation is necessary to understand the underlying physics and effects of different parameters on cooling performance. Numerical study of droplet evaporation has been done by using …


Space Launch Vehicle Design: Conceptual Design Of Rocket Powered, Vertical Takeoff, Fully Expendable And First Stage Boostback Space Launch Vehicles, David Michael Woodward Dec 2017

Space Launch Vehicle Design: Conceptual Design Of Rocket Powered, Vertical Takeoff, Fully Expendable And First Stage Boostback Space Launch Vehicles, David Michael Woodward

Mechanical and Aerospace Engineering Theses - Archive

Engineering design can be broken down into three phases: conceptual design, preliminary design, and detailed design. During the conceptual design phase, several potential configurations are studied towards the identification of the baseline vehicle. Although the least amount of detail is known about the design during the early conceptual design phase, the decisions made during this phase lock in major features effecting life-cycle cost and overall product success. As the next big space race begins, it is critically important to have a readily available tool for launch vehicle designers that is intuitive to use, easy to modify, cost effective, and provides …


A Methodology For Topology And Lattice Structure Optimization Of A Cargo Drone Motor Mount, Nagadurga Srinivas Sripada Dec 2017

A Methodology For Topology And Lattice Structure Optimization Of A Cargo Drone Motor Mount, Nagadurga Srinivas Sripada

Mechanical and Aerospace Engineering Theses - Archive

This work discusses a CAE driven methodology for designing a lightweight component by performing structural configuration on a given package space, creating a closed surface along this configuration using an interactive geometric modeling tool, and lastly generating lattice members that provide the required stiffness for the structure. The design process is explained starting with topology optimization performed on a single block with specific design constraints. It describes the effect of different parameters on the optimized results and how to analyze these results based on a given volume fraction constraint with the objective of minimizing the compliance. It then talks about …


Region Based Convolutional Neural Networks For Object Detection And Recognition In Adas Application, Sachit Kaul Dec 2017

Region Based Convolutional Neural Networks For Object Detection And Recognition In Adas Application, Sachit Kaul

Mechanical and Aerospace Engineering Theses - Archive

Object Detection and Recognition using Computer Vision has been a very interesting and a challenging field of study from past three decades. Recent advancements in Deep Learning and as well as increase in computational power has reignited the interest of researchers in this field in last decade. Implementing Machine Learning and Computer Vision techniques in scene classification and object localization particularly for automated driving purpose has been a topic of discussion in last half decade and we have seen some brilliant advancements in recent times as self-driving cars are becoming a reality. In this thesis we focus on Region based …


The Design And Linearization Of Flow Control Device And Pressure Forces On Valve, Penchala Sumanth Reddy Challa Dec 2017

The Design And Linearization Of Flow Control Device And Pressure Forces On Valve, Penchala Sumanth Reddy Challa

Mechanical and Aerospace Engineering Theses - Archive

Emerging technologies are pushing the limits by reducing the size of the nodes, raising the heat densities of packages thereby demanding better thermal management. The cooling power requirement increases drastically when air is used as the cooling medium in high power density servers as air has a low heat transfer coefficient. Very viable replacements for air as the cooling medium are water and oil. Oil is not as widely used as it has its own disadvantages when compared to water. Water has appreciably higher heat transfer coefficient, which helps it to remove heat from the server at a much faster …


Computational Model For Steady State Simulation Of A Solid Oxide Fuel Cell (Sofc) Planar Stack Model Undergoing Reforming Process, Vaibhav Vijay Indulkar Dec 2017

Computational Model For Steady State Simulation Of A Solid Oxide Fuel Cell (Sofc) Planar Stack Model Undergoing Reforming Process, Vaibhav Vijay Indulkar

Mechanical and Aerospace Engineering Theses - Archive

Solid Oxide Fuel Cell (SOFC), is a clean and low-pollution technology of generating power of high efficiency. Its applicability for both stationery and transportation power generation systems, adaptability for wide range fuel sources, as wells its process of direct conversion of fuel to energy make it an important source of power generation. An effective design of sub-systems or individual components play a key role in overall working of a plant. Thus, critical analysis at the component level is of importance for the overall plant efficiency. In the present study a heat transfer model of a planar SOFC stack to be …


Reliability Assessment Of Solder Joint Using Bga Package – Megtron 6 Versus Fr4 Printed Circuit Boards Using Drop Testing, Pradnya Chandrakant Mundhe Dec 2017

Reliability Assessment Of Solder Joint Using Bga Package – Megtron 6 Versus Fr4 Printed Circuit Boards Using Drop Testing, Pradnya Chandrakant Mundhe

Mechanical and Aerospace Engineering Theses - Archive

In electronic industry Ball grid array (BGA) package, surface mount technology has been used widely, due to its robust design, high density connections and improved performance. In surface mount technology, solder joints are used to interconnect package and PCB board assembly. High frequency laminates use in PCB boards provides excellent performance for high speed, frequency devices. Nelco 4000-13EPSI, Panasonic Megtron 6, and Rogers 4350B are few popular laminates. Component size reduction and structural complexity because of increasing number of transistors are making it very difficult to protect the packages from mechanical, thermal, and electrical damage. Difference in material properties between …