Open Access. Powered by Scholars. Published by Universities.®

Aerospace Engineering Commons™

Open Access. Powered by Scholars. Published by Universities.®

2016

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 271 - 300 of 543

Full-Text Articles in Aerospace Engineering

A Solution To The Circular Restricted N Body Problem In Planetary Systems, Jay R. Iuliano Jun 2016

A Solution To The Circular Restricted N Body Problem In Planetary Systems, Jay R. Iuliano

Master's Theses

This thesis is a brief look at a new solution to a problem that has been approached in many different ways in the past - the N body problem. By focusing on planetary systems, satellite dynamics can be modeled in a fashion similar to the Circular Restricted Three Body Problem (CR3BP) with the Circular Restricted N Body Problem (CRNBP). It was found that this new formulation of the dynamics can then utilize the tools created from all the research into the CR3BP to reassess the possibility of different complex trajectories in systems where there are more than just two large …

Go to article

Investigation Of Thermal Scaling Effects For A Turbine Blade Leading Edge And Pressure Side Model, Ryan A. Lynch Jun 2016

Investigation Of Thermal Scaling Effects For A Turbine Blade Leading Edge And Pressure Side Model, Ryan A. Lynch

Theses and Dissertations

Recent experiments have attempted to quantify the overall cooling effectiveness at elevated temperature conditions. The Film Cooling Rig (FCR) at the Air Force Institute of Technology has been modified to better match the configuration of a similar large scale, low temperature rig at the Air Force Research Laboratory. This has enabled comparison and trend identification of how various properties scale from the low to high temperature condition. Various internal cooling and hole geometry configurations were investigated over a range of temperatures while utilizing the thermal scaling capability of Inconel 718. Film cooling trends and measures of overall effectiveness were matched, …

Go to article

Multi-Stage Axial Compressor With Counter-Rotation Using Accessory Drive, Vinod Gehlot, Magdy S. Attia May 2016

Multi-Stage Axial Compressor With Counter-Rotation Using Accessory Drive, Vinod Gehlot, Magdy S. Attia

Publications

A multi-stage axial compressor for counter rotation. A first series of rotor blade assemblies are mounted on and rotate with the driveshaft, each rotor blade assembly of the first series comprising a rotating stage of the multi-stage axial compressor. A second series of rotor blade assemblies provide a counter-rotating stage of the multi-stage axial compressor. An accessory drive links the second series of rotor blade assemblies to the driveshaft and causes counter-rotation of the second series of rotor blade assemblies.

Go to article

Semi-Empirical Modeling Of Two-Dimensional And Three-Dimensional Dynamic Stall, Ramin Modarres May 2016

Semi-Empirical Modeling Of Two-Dimensional And Three-Dimensional Dynamic Stall, Ramin Modarres

McKelvey School of Engineering Graduate Student Theses & Dissertations

Helicopters are generally limited in their performance by the phenomenon of dynamic stall. The purpose of this work is to develop a method for modeling dynamic stall that is appropriate to preliminary design and flight simulator applications. Unlike other semi-empirical dynamic stall models, the model developed in this thesis, not only counts for the well-known, three-dimensional flow effects on the stalled loads but also captures the secondary vortex-shedding phenomenon that has been seen in experiments. The fundamental physics that modify dynamic-stall behavior and that have been extended from two-dimensional to three-dimensional flow are, namely: 1.) yawed flow, 2.) time-varying velocity, …

Go to article

Multi-Static Mimo Along-Track Interferometry (Atl), Chad Knight, Ross Deming, Jake Gunther May 2016

Multi-Static Mimo Along-Track Interferometry (Atl), Chad Knight, Ross Deming, Jake Gunther

Space Dynamics Laboratory Publications

Along-track interferometry (ATI) has the ability to generate high-quality synthetic aperture radar (SAR) images and concurrently detect and estimate the positions of ground moving target indicators (GMTI) with moderate processing requirements. This paper focuses on several different ATI system configurations, with an emphasis on low-cost configurations employing no active electronic scanned array (AESA). The objective system has two transmit phase centers and four receive phase centers and supports agile adaptive radar behavior. The advantages of multistatic, multiple input multiple output (MIMO) ATI system configurations are explored. The two transmit phase centers can employ a ping-pong configuration to provide the multistatic …

Go to article

Continuum And Molecular-Dynamics Simulation Of Nanodroplet Collisions, Raunak Bardia, Zhi Liang, Pawel Keblinski, Mario F. Trujillo May 2016

Continuum And Molecular-Dynamics Simulation Of Nanodroplet Collisions, Raunak Bardia, Zhi Liang, Pawel Keblinski, Mario F. Trujillo

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The Extent to Which the Continuum Treatment Holds in Binary Droplet Collisions is Examined in the Present Work by using a Continuum-Based Implicit Surface Capturing Strategy (Volume-Of-Fluid Coupled to Navier-Stokes) and a Molecular Dynamics Methodology. the Droplet Pairs Are Arranged in a Head-On-Collision Configuration with an Initial Separation Distance of 5.3 Nm and a Velocity of 3 Ms-1. the Size of Droplets Ranges from 10-50 Nm. Inspecting the Results, the Collision Process Can Be Described as Consisting of Two Periods: A Preimpact Phase that Ends with the Initial Contact of Both Droplets, and a Postimpact Phase Characterized by the Merging, …

Go to article

The Context Of Tool Control In An Aircraft Assembly Environment Related To Productivity, Taylor Jay Sisson May 2016

The Context Of Tool Control In An Aircraft Assembly Environment Related To Productivity, Taylor Jay Sisson

KSU Journey Honors College Capstones and Theses

The aircraft industry focuses a large portion of its resources on tool control during the assembly of aircraft. Tool control is a strict process that demands time from the assembly process. This time is removed from the value-added time spent actually assembling the aircraft. A study at Lockheed Martin conducted in the Spring of 2016 is discussed that examines the time spent on tool control. Tool control is necessary in aircraft assembly to prevent tools from entering compartments of the aircraft. If such an event occurs, the tool may damage the aircraft. All aircraft assembly processes must be tool controlled, …

Go to article

Uav As A Service: Providing On-Demand Access And On-The-Fly Retasking Of Multi-Tenant Uavs Using Cloud Services, Justin Yapp May 2016

Uav As A Service: Providing On-Demand Access And On-The-Fly Retasking Of Multi-Tenant Uavs Using Cloud Services, Justin Yapp

Doctoral Dissertations and Master's Theses

As commercial roles for Unmanned Aerial Vehicles (UAVs) become more well-defined and demand for the services provided by them increases, UAVs rely more on new cloud computing services and co-operative coordination to provide mission planning, control, tracking and data processing. We present UAV as a Service (UAVaaS) framework, which brings features commonly found in traditional cloud services, such as Infrastructure, Platform, and Software as a Service, to the domain of UAVs. Our work aims to conceptualize and design UAVaaS for commercial applications. Specifically, a cloud-provided orchestration framework that allows multi-tenant UAVs to easily serve multiple heterogenous clients at once and …

Go to article

Numerical Modeling Of An Alloy Droplet Deposition With Non-Equilibrium Solidification, Vimal Ramanuj May 2016

Numerical Modeling Of An Alloy Droplet Deposition With Non-Equilibrium Solidification, Vimal Ramanuj

Mechanical and Aerospace Engineering Dissertations - Archive

Droplet deposition is a process of extensive relevance to the microfabrication industry. Various bonding and film deposition methods utilize single or multiple droplet impingements on a substrate with subsequent splat formation through simultaneous spreading and solidification. Splat morphology and solidification characteristics play vital roles in determining the final outcome. Experimental methods have limited reach in studying such phenomena owing to the extremely small time and length scales involved. Fundamental understanding of the governing principles of fluid flow, heat transfer and phase change provide effective means of studying such processes through computational techniques. The present study aims at numerically modeling and …

Go to article

Enhanced Specific Heat Of Molten Salt Nanofluids, Hani Tiznobaik May 2016

Enhanced Specific Heat Of Molten Salt Nanofluids, Hani Tiznobaik

Mechanical and Aerospace Engineering Dissertations - Archive

Concentrated solar power uses general thermodynamic cycles (such as Rankine or Gas turbine cycle) to produce electricity and thus its efficiency primarily relies on the operating temperature of thermal energy storage. Current thermal energy storage medium is organic material such as synthetic oil or fatty acid. However, these materials are not stable at high temperatures due to their thermal decomposition. Using molten salts as thermal energy storage medium is a very attractive option since they are thermally stable at high temperatures (over 600 °C). They also have very lower vapor pressure (for reducing mechanical stress on structure materials), less reactive, …

Go to article

Data Engineering In Aerospace Systems Design & Forecasting, Eric Haney May 2016

Data Engineering In Aerospace Systems Design & Forecasting, Eric Haney

Mechanical and Aerospace Engineering Dissertations - Archive

Although engineers spend the majority of their time finding, managing, and transforming data, the process of how to handle data remains under-educated & under-researched. The alignment of engineering education & proficiency along an analysis-dominated mindset is ill-conditioned for the growing reliance on data-driven processes and holistic decision-making requirements. Although a majority of driving decisions in the aerospace industry rely heavily on utilizing existing organizational data-stores and built-in knowledge bases to make informed decisions, formalized development & implementation of data within existing engineering processes is seldom addressed. The current research defines a complementary discipline, Data-Engineering, which seeks to capitalize on the …

Go to article

Exergy Analysis Of A Pulse Detonation Engine Linear Power Generator, Raheem Temitope Bello May 2016

Exergy Analysis Of A Pulse Detonation Engine Linear Power Generator, Raheem Temitope Bello

Mechanical and Aerospace Engineering Dissertations - Archive

The fuel efficiency of a power generator is a key metric for evaluating its performance. The common engineering practice is to determine the thermal efficiency of the system by applying the conservation of energy also known as the first law of thermodynamics. However, for heat engine power generators, and other thermal systems, the thermal efficiency is not sufficient for detailed system performance analysis. Exergy analysis, which applies both the first and second law of thermodynamics, enables the determination of the directionality of thermal processes, and the system’s available work. This more complete thermodynamic analysis approach is applied to a pulse …

Go to article

Maximizing Use Of Air-Side Economization, Direct And Indirect Evaporative Cooling For Energy Efficient Data Centers, Betsegaw Kebede Gebrehiwot May 2016

Maximizing Use Of Air-Side Economization, Direct And Indirect Evaporative Cooling For Energy Efficient Data Centers, Betsegaw Kebede Gebrehiwot

Mechanical and Aerospace Engineering Dissertations - Archive

Data centers house information technology (IT) equipment such as servers and network switches which are vital for our networked modern society by providing digital data storage, data processing and connectivity. Data centers house few hundreds to tens of thousands of IT equipment that consume few kilowatt-hours to multi-megawatt-hours of electrical energy that gets dissipated as heat. IT equipment need to be properly cooled so that they operate reliably for their expected lifetime. For air cooled IT equipment, manufacturers provide heat sinks, cold plates, fans, et cetera to remove heat from the vicinity of heat dissipating components and data centers need …

Go to article

Human Robot Interaction With 3d-Printed Whole Body Robotic Skin, Fahad Mirza May 2016

Human Robot Interaction With 3d-Printed Whole Body Robotic Skin, Fahad Mirza

Mechanical and Aerospace Engineering Theses - Archive

This thesis presents work of a newly developed pressure sensor for robot skin, from fabrication to application. Robot skin similar to human skin meant to have several sensing capabilities including pressure, temperature etc. As the conventional semiconductor manufacturing process is not adequate for multi-modal sensors, a new process, called Electro-Hydro-Dynamic Printing, has been explored in this work. A calibration technique was implemented along with printing parameter fixation by trial and error. A testing methodology was proposed to test these sensors and several commercial robots were used to conduct pHRI experiments with pressure sensing capability.

Go to article

Finite Element Based Cross-Sectional Buckling Optimization For A Constant Area, Pinned-Pinned Composite Column, Anirudh Srinivas May 2016

Finite Element Based Cross-Sectional Buckling Optimization For A Constant Area, Pinned-Pinned Composite Column, Anirudh Srinivas

Mechanical and Aerospace Engineering Theses - Archive

In archery, dynamic buckling compromises the target accuracy of arrows. For both dynamic and quasi-static buckling, the buckling load depends on the cross-sectional area moment of inertia, which can be increased by modifying the cross-sectional shape of the arrow shaft. Arrows commercially available today are made up of composite materials and have a tubular circular cross-section. In this study an effort has been made to optimize the cross-sectional shape of the composite arrow shaft, using finite element based, quasi-static buckling analysis keeping the length and area of the cross-section constant. The composite column is pinned at both ends and is …

Go to article

Human Robot Interaction Using Knowledge Base Approach, Utsav Shah May 2016

Human Robot Interaction Using Knowledge Base Approach, Utsav Shah

Mechanical and Aerospace Engineering Theses - Archive

This research investigated Human Robot Interaction modalities. The performance of a robotic prosthetic hand (RPH) was used as a test bed robot. A user wearable glove was fitted with sensors to provide tele-control of the RPH. An open hardware control and easily expandable research platform based on LabVIEW software and myRIO control hardware was developed. LabVIEW graphical programming platform provides the tools for the development to customized interfaces for visualization purposes which is desired in research. The research platform was used to calibrate and control the operation of the artificial hand using various modalities such as open loop, glove master-slave …

Go to article

E-Learning Modules For Nuclear Reactor Heat Transfer, Praveen Bharadwaj Jayaram May 2016

E-Learning Modules For Nuclear Reactor Heat Transfer, Praveen Bharadwaj Jayaram

Mechanical and Aerospace Engineering Theses - Archive

E learning in engineering education is becoming popular at several universities as it allows instructors to create content that the students may view and interact with at his/her own convenience. Web-based simulation and what-if analysis are examples of such educational content and has proved to be extremely beneficial for engineering students. Such pedagogical content promote active learning and encourage students to experiment and be more creative. The main objective of this project is to develop web based learning modules, in the form of analytical simulations, for the Reactor Thermal Hydraulics course offered by the College of Engineering at UT Arlington. …

Go to article

Experimental And Numerical Study Of Marangoni Convection In A Sandwiched Droplet, Ajinkya Shrikrishna Shetye May 2016

Experimental And Numerical Study Of Marangoni Convection In A Sandwiched Droplet, Ajinkya Shrikrishna Shetye

Mechanical and Aerospace Engineering Theses - Archive

This research studies velocity fields resulted from the marangoni effect in a microscale droplet sandwiched in parallel plates. Surface tension becomes the dominant driving force as opposed to body forces as we move from the macroscale to microscale. Surface tension gradient is required to generate marangoni convection. This could be produced by a temperature gradient along the meniscus of the drop. To study this interfacial phenomenon, indium tin oxide micro thin film heater is utilized to create the necessary temperature gradient. Pure marangoni effect is studied by suppressing the evaporation effect on fluid flow by using an ionic liquid (molten …

Go to article

Computational Analysis Of Blast Induced Damage On Neurons In Brain During Traumatic Brain Injury, Divya Swamy Bandaru May 2016

Computational Analysis Of Blast Induced Damage On Neurons In Brain During Traumatic Brain Injury, Divya Swamy Bandaru

Mechanical and Aerospace Engineering Theses - Archive

Concussions are the most common kind of brain injuries, they are also called as mild Traumatic Brain Injuries (mTBI). In recent times, mTBIs are perceived as one of the major health problems faced by millions across the world. TBIs occur when there is a sudden acceleration or deceleration force is applied on the human brain that is encapsulated in the skull. When blasts caused by typical IEDs (induced by explosives) in wars propagate through the head, cavitation bubbles are formed in the brain tissue. When these bubbles collapse, they form cavitation-induced shock wave. It has been found that the strains …

Go to article

Image Processing Of Triple Shock Wave Evolution, Katherine Yarbrough May 2016

Image Processing Of Triple Shock Wave Evolution, Katherine Yarbrough

Mechanical and Aerospace Engineering Theses - Archive

Shock diamonds occur in over- or under- expanded supersonic flow. They occur in the unsteady jet of a pulse detonation engine, displaying an array of complex features. Due to the highly transient nature of the flow, it must be captured using high-speed cinematography. A study of image processing of shock reflection in unsteady flow is presented. Using a computer-based environment, a method was developed to process images of shock waves to pinpoint where the shock wave starts. Using mathematical methods, such as Abel transforms, a computer code, written in Matlab, was developed to accurately transform the images to detect density …

Go to article

Experimental Characterization Of Hybrid Cooled Cisco Servers Including The Effect Of Warm Water Cooling, Md Malekkul Islam May 2016

Experimental Characterization Of Hybrid Cooled Cisco Servers Including The Effect Of Warm Water Cooling, Md Malekkul Islam

Mechanical and Aerospace Engineering Theses - Archive

The information technology (IT) owners are experiencing a greater cooling challenge because of the increase in power density due to modern computational needs. The non-uniform power density in each server is forcing the industry to use hybrid cooling technology. Server components of different cooling requirement needs air water hybrid cooling which offers variable design alternatives. Such hybrid cooling technology cools the high heat generating components by using water or water based fluid, whereas, the rest of the components are cooled by air using internal fans. Conventional air cooling is more than sufficient for the components with less thermal demand. Air …

Go to article

Performance Enhancement Of Raspberry Pi Server For The Application Of Oil Immersion Cooling, Dhaval Hitendra H Thakkar May 2016

Performance Enhancement Of Raspberry Pi Server For The Application Of Oil Immersion Cooling, Dhaval Hitendra H Thakkar

Mechanical and Aerospace Engineering Theses - Archive

The power consumed by Central Processing Unit (CPU) generates the heat which is undesirable and which is further responsible for the damage of Information Technology equipment. Oil Immersion cooling is one of the emerging technology which deals with the high server densities by submersing the servers in mineral oil. The study addresses the CFD analysis of Raspberry Pi computer servers with different cooling techniques and different modes of operating conditions. The thesis gives the explanation on the difference between air cooling and oil cooling with and without use of heat sinks. The study also shows the parametric analysis of heat …

Go to article

Parametric Cycle Analysis Of Adaptive Cycle Engine, Harinkumar Rajendrabhai Patel May 2016

Parametric Cycle Analysis Of Adaptive Cycle Engine, Harinkumar Rajendrabhai Patel

Mechanical and Aerospace Engineering Theses - Archive

One of the main area of research currently in air-breathing propulsion is increasing the fuel efficiency of engines. Increasing fuel efficiency of an air-breathing engine will be advantageous for civil transport as well as military aircraft. This objective can be achieved in several ways. Present design models are developed based on their uses: commercial transport, high range rescue aircraft, military aircraft. One of the main property of military aircraft is possessing high thrust but increasing fuel efficiency will also be advantageous resulting in more time in combat. Today's engine design operates best at their design point and has reduced thrust …

Go to article

Finite Element Based Weight Reduction Subject To Stability Constraints For An Airship Composite Duct, Soham M. Umbrajkar May 2016

Finite Element Based Weight Reduction Subject To Stability Constraints For An Airship Composite Duct, Soham M. Umbrajkar

Mechanical and Aerospace Engineering Theses - Archive

The primary functions of High Altitude Long Endurance (HALE) airships are persistent observation and wide area direct line of sight communication. Traditional airships have an ellipsoidal type hull, which is characterized by a large aspect ratio but results in an increase in the weight of the envelope. In order to reduce the weight of an airship, a hull having lower aspect ratio would be preferred. A novel unconventional airship design having a toroidal geometry with a propulsive duct running from the front end to back end was developed by Dancila in an attempt to achieve this objective. The propulsive duct …

Go to article

A Study Of Electrical Double Layer At An Aluminum Surface In An Automotive Cooling System, Saurabh Deobhankar May 2016

A Study Of Electrical Double Layer At An Aluminum Surface In An Automotive Cooling System, Saurabh Deobhankar

Mechanical and Aerospace Engineering Theses - Archive

Electrolytic corrosion is identified as a major problem which adversely affects the performance of a cooling system and hence compromises the performance of automobile with it. Electrolysis corrosion is a chemical reaction process that occurs between a metal surface and electrolyte. Mostly, the radiator tubes and tanks are made of aluminum with a high heat transfer rate. The coolant flows under pressure through the aluminum tubes, which gives rise to erosion-corrosion. The present thesis sheds light on the corrosion mechanism of Al 3003 alloy radiator tubes in contact with 50/50 ethylene glycol water coolant. The main objective is to understand …

Go to article

Cfd Modelling Of Wet Cooling Media And Design Optimization Of Heat Sink For Data Center Application, Shivang Yogeshkumar Desai May 2016

Cfd Modelling Of Wet Cooling Media And Design Optimization Of Heat Sink For Data Center Application, Shivang Yogeshkumar Desai

Mechanical and Aerospace Engineering Theses - Archive

Air cooling is most widely used and economical method of currently available cooling technologies in which heat exchanger plays a vital role in facility designs. Evaporative cooling can be energy efficient than mechanical cooling because it uses water’s enthalpy of vaporization. Wet cooling pads can be used as the direct evaporative cooling system in which pad is made of cellulose fibers those gets wet when water injected. When hot and dry air passes through pad surfaces, water evaporates in the air which cools down air adiabatically increasing humidity. These type of cooling units can be installed in these type of …

Go to article

Design And Parametric Analysis Of Flow Control Device For Dynamic Cold Plate To Optimize The Temperature Fluctuations Of The Multi-Chip Module, Avinash Veluturla May 2016

Design And Parametric Analysis Of Flow Control Device For Dynamic Cold Plate To Optimize The Temperature Fluctuations Of The Multi-Chip Module, Avinash Veluturla

Mechanical and Aerospace Engineering Theses - Archive

Continuing trends of increasing microprocessor power densities and non-uniform temperature distribution pose a significant challenge to the data center cooling. The most usual approach to data center cooling is air cooling but there are certain limitations to that approach. Major limitation is heat transfer coefficient so in order to overcome those limitations, we came up with liquid cooling using water as coolant. To minimize energy consumption of cooling system the objective is to design a dynamic energy efficient and practical cooling solution for high power equipment. Multi-chip module is used as the base for the liquid cooling solution. The main …

Go to article

Computational Analysis Of Impact Loading On Wafer Level Chip Scale Packages Mounted On Printed Circuit Boards Of Varying Thickness, Anik Mahmood May 2016

Computational Analysis Of Impact Loading On Wafer Level Chip Scale Packages Mounted On Printed Circuit Boards Of Varying Thickness, Anik Mahmood

Mechanical and Aerospace Engineering Theses - Archive

In the electronic industry one of the popular package is Chip Scale Package (CSP) due to its small form factor and low cost. To meet the need of new functionality and portability of the recent devices, CSPs’ have been most favorable choice for a long time. On the other hand, with the miniaturization process of these portable devices there is a growing risk of drop impact failure in day to day use. It’s not only the mechanical loading that is affecting the reliability of these devices but also thermal and thermo-mechanical loads are acting simultaneously. To analyze and ensure the …

Go to article

Evaluation Of Cooling Architectures And Control Strategies In Airflow Provisioning A Modular Data Center, Jaykishankumar Kunjbihari Patel May 2016

Evaluation Of Cooling Architectures And Control Strategies In Airflow Provisioning A Modular Data Center, Jaykishankumar Kunjbihari Patel

Mechanical and Aerospace Engineering Theses - Archive

To achieve energy efficiency and reduce operational costs in data centers with modularized Information Technology and cooling infrastructure there is an ongoing trend to minimize the use of mechanical cooling and instead use outdoor air in favorable environmental conditions for cooling purposes. The cooling module can comprise of evaporative cooling systems which use direct, indirect or a combination of direct/indirect evaporative cooling units to provide adequate cooling. The degree of cooling achieved in the IT module depends on the effective airflow provisioned and the air distribution methods employed. In this study, a modular data center which is equipped with a …

Go to article

Cfd Based Design And Optimization Of Louver Blade Angles To Enhance Better Air Flow Distribution And Improve Thermal Efficiency Of It Equipment In Data Centers, Avinash Kumar Ray May 2016

Cfd Based Design And Optimization Of Louver Blade Angles To Enhance Better Air Flow Distribution And Improve Thermal Efficiency Of It Equipment In Data Centers, Avinash Kumar Ray

Mechanical and Aerospace Engineering Theses - Archive

A data center is a depository which stores, processes and distribute large amounts of data and information using computer systems and associated components for power supplies, cooling systems. Modular data center is a portable method of deploying traditional large data center capacity into a small portable unit. According to the Uptime Institute, the amount of heat generated inside IT equipment has been increasing significantly. Data centers are using nearly 60% of their power in employing expensive cooling techniques. In addition, the cost of cooling has necessitated a need to reduce or eliminate mechanical cooling. As such, Air Economization, Direct and …

Go to article

First Prev Next Last