Four-Wavelength Lidar For In-Situ Speciation Of Aerosols,
2018
Space Dynamics Laboratory
Four-Wavelength Lidar For In-Situ Speciation Of Aerosols, Michael Wojcik, Alan Bird, Jason Wooden, Jim Peterson, Morgan Davidson, Monte Frandsen
Space Dynamics Laboratory Publications
The system and mechanical design of a four-wavelength lidar system is described. The system is designed to be maximally adaptive to deployment scenario in terms of both size/weight/power and detection application. The wavelengths included in the system are 266 nm, 355 nm, 1064 nm, and 1574 nm – all generated from Nd:YAG based pump laser sources. The system is designed to have a useful range from 400 meters to 5,000 meters, depending on the wavelength and atmospheric conditions.
Linear And Nonlinear Adaptive Attitude Control Of Asteroid-Orbiting Spacecraft Using State Feedback And Output Feedback,
2018
University of Nevada, Las Vegas
Linear And Nonlinear Adaptive Attitude Control Of Asteroid-Orbiting Spacecraft Using State Feedback And Output Feedback, Nicholas Moya
UNLV Theses, Dissertations, Professional Papers, and Capstones
This thesis presents the derivation of both a linear and nonlinear adaptive control law for the attitude states of a spacecraft in orbit around rotating asteroids. The asteroid is assumed to be irregularly shaped and in an elliptical orbit around the sun. The linearized, time-varying spacecraft model will assume to include unknown parameters and will have external disturbances present. The objective is to control the roll, pitch, and yaw angle trajectories of the spacecraft such that they track desired reference trajectories. To achieve this, the control law will be composed of (1) a feedback controller, sufficiently robust to disturbance such …
Electric Aircraft And The Environment: A Literature Review,
2018
San Jose State University
Electric Aircraft And The Environment: A Literature Review, Uyen T. Sou
McNair Research Journal SJSU
Historically, the integration of social need, environmental impact, and technological advancement has been a challenging balancing act for growing cities and metropoles. If the balance between social need and environmental sustainability is reached, the increasing advancements and improvements made to electric aircrafts have the potential to steer society towards a new mode of sustainable air. One reason why electric aircraft technology has not grown as fast as other technologies is because there lacked a need for fast advancements. With that said, electric aircraft technologies are improving today due to the demand in heavily populated cities to relieve traffic [5]. Some …
Validation Of Cfd Simulations For Hypersonic Flow Over A Yawed Cone,
2018
Washington University in St. Louis
Validation Of Cfd Simulations For Hypersonic Flow Over A Yawed Cone, Julian Cecil
McKelvey School of Engineering Graduate Student Theses & Dissertations
This study aims to numerically simulate the wind tunnel results for hypersonic flow over a circular cone of semi-apex angle of 10 degrees yawed from 0° to 20° using the commercial computational fluid dynamics software ANSYS Fluent. The ANSYS workbench is used to create the 10° semi-apex circular cone with a shock aligned structured mesh of 3.05 million cells surrounding the cone. Simulation boundary conditions for pressure and temperature in the far field correspond to Tracy’s wind tunnel experiment at Cal Tech. The six simulations cases are conducted for yaw angles of 0, 8, 12, 16, 20 and 24 degrees. …
The Drag Coefficient Of Varying Dimple Patterns,
2018
Linfield College
The Drag Coefficient Of Varying Dimple Patterns, James M. Seeley, Michael S. Crosser
Senior Theses
There are many golf balls on the market today with varying dimple sizes, shapes, and distribution. These proprietary differences are all designed to reduce drag on the balls during flight, allowing golfers to hit the ball farther distances. There are limited published studies comparing how varying the dimples affects the reduction of drag. An experiment was developed in which golf balls were pulled through a water tank to measure the drag force acting on each ball. The water was chosen to allow for testing at slower velocities than the typical necessary speeds to cause turbulence for balls traveling in air. …
Innovation In Commercial Supersonic Aircraft With Candidate Engine For Next Generation Supersonic Aircraft,
2018
Kennesaw State University
Innovation In Commercial Supersonic Aircraft With Candidate Engine For Next Generation Supersonic Aircraft, Christopher D. Roper, Jordan Fraser, Alain J. Santos
Senior Design Project For Engineers
The objective of this design study and competition - Next Generation Supersonic Candidate Engine and Aircraft Design, is a response to a proposal and is motivated by NASA’s National Research Announcement in 2006. The requirements of this design study are provided by AIAA (American Institute of Aeronautics and Astronautics). The aircraft designed is a private business class. The aircraft engine performs at a maximum speed of Mach 1.8 and supersonic cruise speed of Mach 1.6 at 55,000 feet and a range of 4000 nmi. A generated mission profile through considerations in flight regime will drive the design involved in the …
Experimental Investigation Of Fischer-Tropsch Synthesis With A Modified Catalyst Support,
2018
University of Texas at Arlington
Experimental Investigation Of Fischer-Tropsch Synthesis With A Modified Catalyst Support, Pawarat Bootpakdeetam
Mechanical and Aerospace Engineering Dissertations - Archive
Energy demand has been rapidly increasing in the last 30 years due to the population growth and high demand by industries. However, as natural energy sources are limited, they cannot meet this increased energy demand. Therefore, alternative energies have become an option to sustain current and future energy demands. One promising and reliable alternative energy is the Fischer-Tropsch synthesis (FTS), which is a gas-to-liquid (GTL) technology that converts syngas from a low-value feedstock, for example, from coal, biomass, or natural gas, into a high-value liquid hydrocarbon. In addition, FTS is a highly exothermic catalytic reaction that requires careful thermal management …
Reconfigurable Electrochemical Biosensor Enabled By Digital Microfluidic Devices,
2018
University of Texas at Arlington
Reconfigurable Electrochemical Biosensor Enabled By Digital Microfluidic Devices, Ali Farzbod
Mechanical and Aerospace Engineering Dissertations - Archive
The increasing demand for improving the health care quality in developed countries with synchronous advances in the microfabrication of CMOS devices results in the emergence of the Lab-on-a-chip (LOC) field. The ultimate goal of LOC's is to achieve the complete integration of biomedical protocols, such as sample pre-processing and separation and analysis of biosamples on a chip. Electrowetting on dielectric (EWOD) as a distinctive digital microfluidic (DMF) is capable of manipulating droplets less than a microliter along the electrode arrays by applying AC voltages. EWOD chips, as microfluidic platforms, are inherently electrical and do not have to deal with problems …
A Two Stage Event Based Data Driven Controller For Improved Grasping Of An Artificial Hand,
2018
University of Texas at Arlington
A Two Stage Event Based Data Driven Controller For Improved Grasping Of An Artificial Hand, Christopher Abrego
Mechanical and Aerospace Engineering Dissertations - Archive
The human hand is one of the greatest (if not the greatest) tool known to mankind for grasping objects. So much so, that researchers have been investigating the development of artificial biomimetic hands in an effort to mimic their functionality and dexterity with the indent to apply the technology to various robotic platforms; ranging from end effectors for industrial pick-and-place robotics, to upper-limb prosthetics, to humanoids. There are certain features that make this endeavor challenging such as the mechanical design, actuation and sensorization, and functionality as well as the interaction from both the view point of interacting with an end …
Finite Element Analysis Of Composite Water Buffer Drum,
2018
University of Texas at Arlington
Finite Element Analysis Of Composite Water Buffer Drum, Chinmay Shrikrishna S Godbole
Mechanical and Aerospace Engineering Theses - Archive
Composite materials offer many advantages for to many industries and developments based on their low density, corrosion resistance, and high strength to weight ratio. In addition, the use of composites allows for more design flexibility for products, the properties to meet specific design requirements, thus promoting better system oriented and cost-effective solutions. However, on a high performance equated basis, the economic incentive to use composite components can often be demonstrated based on their capability to reduce system and life cycle costs. Water buffer drum which is a pressure vessel holds a specified volume of fluid with desired temperature and pressure. …
On The Development And Integration Of Pneumatic Extrusion Module And A Methodology To Identify Process Parameters For Additive Manufacturing Using Machine Learning,
2018
University of Texas at Arlington
On The Development And Integration Of Pneumatic Extrusion Module And A Methodology To Identify Process Parameters For Additive Manufacturing Using Machine Learning, Kashish Dhal
Mechanical and Aerospace Engineering Theses - Archive
Commonly used additive manufacturing platforms have a single extrusion module based on Fused Filament Fabrication (FFF) and their processing software generates G-Codes for this FFF module using defined process parameters. These platforms and software do not accommodate different processing modules such as viscous extruders or Direct Ink Writing (DIW). This research is focused on the development of a Pneumatic Extrusion Module (PEM) capable of dispensing viscous materials such as gels or slurries controlled through a digital pneumatic valve. A PEM is developed, integrated and its performance is evaluated on a multi-modality additive manufacturing platform in the MARS Lab. The operation …
Experimental Analysis Of A Single-Phase Direct Liquid Cooled Server Performance At Extremely Low Temperatures For Extended Time Periods,
2018
University of Texas at Arlington
Experimental Analysis Of A Single-Phase Direct Liquid Cooled Server Performance At Extremely Low Temperatures For Extended Time Periods, Gautam Gupta
Mechanical and Aerospace Engineering Theses - Archive
A data center is a centralized facility that we use for housing the computer systems and its related components such as high-end servers, redundant data connection and security controls. The next radical change in the thermal management of data centers is to shift from conventional cooling methods like air-cooling to direct liquid cooling (DLC) to deal with high thermal mass. The past few years have consistently seen wider adoption of direct liquid cooling because of its simplicity and high heat dissipation capacity. Passive single phase engineered fluid immersion cooling has several other benefits like better server performance, even temperature profile …
Quasi-One-Dimensional Scramjet Combustor Flow Solver Using The Numerical Propulsion System Simulation,
2018
University of Texas at Arlington
Quasi-One-Dimensional Scramjet Combustor Flow Solver Using The Numerical Propulsion System Simulation, Long Vu
Mechanical and Aerospace Engineering Theses - Archive
The flow field inside a scramjet engine combustor involves complex phenomena such as fuel-air mixing, combustion chemistry, and flow separation. In order to determine the properties of the flow along the length of the combustor, mass, momentum and energy balance equations are solved simultaneously using a numerical method. While a full three dimensional computational simulation gives detailed results with high order of accuracy, it demands a great amount of time and computational resource. A low order analysis produces a fast overall picture of the combustor operation which in turn provides valuable information suitable for the preliminary design process. This research …
Robot Motion Tracking Using Time-Of-Flight And Structured Light Sensors For Indoor Navigation,
2018
University of Texas at Arlington
Robot Motion Tracking Using Time-Of-Flight And Structured Light Sensors For Indoor Navigation, Karan Vishnu Rao
Mechanical and Aerospace Engineering Theses - Archive
Simultaneous localization and mapping for mobile robots has been an active research field for several years with focus on the problems of accuracy and dependability of the data from the robot's peripherals. The position estimates for mobile and industrial robots is usually achieved by using the information from the global positioning system in an outdoor environment and for indoor environment, technologies such as LiDAR sensors and Infrared (IR) camera based motion capture systems such as VICON (TM) are used. The main issue with these approach for indoor navigation is the monetary cost to associated with these technologies. The purpose of …
Comparison Of Carbon Steel And Composite Side Wall Of Light Rail Vehicle By Finite Element Analysis,
2018
University of Texas at Arlington
Comparison Of Carbon Steel And Composite Side Wall Of Light Rail Vehicle By Finite Element Analysis, Dilraj Singh
Mechanical and Aerospace Engineering Theses - Archive
A Railroad car is a vehicle used for carrying passengers and cargo. In the modern era, rail vehicles are designed as lightweight structures with the aim to minimize mass, operational energy demands, and CO2 emissions. Light rail vehicle is used at street level where they have direct contact with normal traffic and have a short distance between stations. In order to reduce dwell time at stops, and so, the vehicle can accelerate and deaccelerate easily, weight should be less and that is why low floor design is adopted these days. The sidewall is a crucial part of the car body …
Airflow Path And Flow Pattern Analysis Of Sub-Micron Particulate Contaminants In A Data Center With Hot Aisle Containment System Utilizing Direct Air Cooling,
2018
University of Texas at Arlington
Airflow Path And Flow Pattern Analysis Of Sub-Micron Particulate Contaminants In A Data Center With Hot Aisle Containment System Utilizing Direct Air Cooling, Satyam Saini
Mechanical and Aerospace Engineering Theses - Archive
The percentage of the energy used by data centers for cooling their equipment has been on the rise. With it has been the necessity for exploring new and more efficient methods, both from an engineering as well as business point of view, to contain this energy demand. The PCB boards are becoming more densely populated with multitude of smaller hardware on them, thereby, increasing its cooling requirements. Literature suggests that almost 40% of the total energy consumption in a typical Data Center is used for cooling purposes. Air cooling has always been the first choice for IT companies to cool …
Experimental Characterization Of Vertically Split Distribution Wet- Cooling Media Used In Direct Evaporative Cooling Of Data Center,
2018
University of Texas at Arlington
Experimental Characterization Of Vertically Split Distribution Wet- Cooling Media Used In Direct Evaporative Cooling Of Data Center, Ahmed Al Khazraji
Mechanical and Aerospace Engineering Theses - Archive
When operating in direct evaporative cooling (DEC) mode, the amount of moisture added to a system can be controlled by frequently modulating water supply to the wet cooling media. Though many challenges arise due to geographical and site conditions, this concept can be applied to data centers to serve as a cost-effective alternative for maintaining the operating temperature of the facility at any weather condition. However, this method results in scale and mineral build up on the media because of an irregular water distribution. To prevent the scale formation, the operators allow the water supply continuously on the cooling media …
Investigation On Effective Modulus And Stress Concentration Factor Of 3d Reinforced Composite By Finite Element Analysis Method,
2018
University of Texas at Arlington
Investigation On Effective Modulus And Stress Concentration Factor Of 3d Reinforced Composite By Finite Element Analysis Method, Chandra Bhaskar Reddy Pittu
Mechanical and Aerospace Engineering Theses - Archive
Micromechanics of Composites aims to analyze the localized stresses inside any given constituents of the composite structure. This Thesis is focused on Calculating the effective modulus and the Stress concentration factor of the 3D straight Fiber Composite using Finite Element(FE). The compressive and a Shear response of a 3D Straight fiber composite comprising three directional E Glass Fibers reinforced in an epoxy matrix is analysed. This result is the 10% of overall Composite Ductility and a 10% of overall Shear displacement load in the orthogonal directions. FE calculations are reported to analyse the response of 3d reinforcement as of with …
Optimization Of Heating, Ventilation, And Air-Conditioning (Hvac) Chilled Water Plant Systems,
2018
University of Texas at Arlington
Optimization Of Heating, Ventilation, And Air-Conditioning (Hvac) Chilled Water Plant Systems, Cliff Odhiambo Nudi
Mechanical and Aerospace Engineering Theses - Archive
Heating, Ventilation, and Air-conditioning accounts for about 60% of the total energy consumed in commercial facilities including office buildings, hospitals, retail stores, warehouses, campuses, manufacturing facilities, medical facilities, etc. As the cost of electricity and energy continue to rise, building owners and facility managers continue to witness a rise in the Total Cost of Ownership. Chilled water plant system is the largest consumer of energy in HVAC system consuming 75% of the total energy used in HVAC according to the Department of Energy. Operating chilled water plant systems at the recommended AHRI Standard 550/590 for performance rating of water chilling …
Design And Experimental Study Of Hydrostatic Thrust Air Foil Bearing,
2018
University of Texas at Arlington
Design And Experimental Study Of Hydrostatic Thrust Air Foil Bearing, Myong Sok Song
Mechanical and Aerospace Engineering Theses - Archive
Oil-free bearing technology has several advantages over conventional oil-lubricated bearings. These advantages include high-speed operation, reduced weight, and increased reliability. Consequently, oil-free technology is expected to replace conventional bearings in a variety of applications. However, many challenges need to be addressed for widespread adoption of oil-free technology such as lower load capacity during start/stop and issues with controlling temperature. Thrust bearings, unlike their radial counterparts, are used for supporting axial loads and have become more important in recent years because of layout requirements other than double overhang configuration gaining consideration for specialized applications. Moreover, the requirements are demanding more extreme …
