Flow Measurement Using Electron Beam Flourescence,
2018
Purdue University
Flow Measurement Using Electron Beam Flourescence, Richard Brookes, Andrew Strongrich, Anthony G Cofer, Alina Alexeenko
The Summer Undergraduate Research Fellowship (SURF) Symposium
Low density, high-speed flows are of interest to many research areas including, spacecraft thrusters, hypersonic vehicle control, and atmospheric re-entry studies. Measurement of low-density gas flows by traditional methods such as Schlieren Photography or Particle Image Velocimetry is often not possible. In order to yield new information about gas behavior at low densities the technique of electron beam fluorescence is being re-evaluated. By recreating previous electron beam fluorescence setups used to measure density, the experiment operating parameters including beam strength and density ranges are assessed and a foundation can be built for further experimentation. Comparing intensity plots of imaged flows …
Extra-Terrestrial Habitat Systems: Safety, Reliability, And Resilience,
2018
Purdue University
Extra-Terrestrial Habitat Systems: Safety, Reliability, And Resilience, Jory C. Lyons Jr., Amin Maghareh, Audai Theinat, Shirley Dyke, Antonio Bobet
The Summer Undergraduate Research Fellowship (SURF) Symposium
Developing a resilient extra-terrestrial habitat with regards to long-term reliability and safety from hazards including radiation, meteorites, and quakes is necessary to ensure human survival during interplanetary exploration. The objective of this study is to examine conventional aerospace safety and reliability analysis techniques to investigate whether they are sufficient to achieve resilience in extra-terrestrial habitats. These results will be obtained to complete a strengths, weaknesses, opportunities, and threats (SWOT) analysis of compiled techniques to design a sustainable habitat system. Failure modes, effects, and criticality analysis (FMECA) and probabilistic risk assessment (PRA) with their past applications will be assessed to provide …
Space Architecture Assessment Using System-Of-Systems Methodologies,
2018
Purdue University
Space Architecture Assessment Using System-Of-Systems Methodologies, Liam Durbin, Cesare Guariniello, Daniel Delaurentis
The Summer Undergraduate Research Fellowship (SURF) Symposium
As technologies in the space exploration community are further developed, mission complexity and the associated risks have become greater. Dozens of complicated system interactions may result in unexpected, potentially dangerous emergent behaviors. Early efforts are underway by NASA to map potential system architectures (collections of systems which fulfill design requirements) for future human space exploration missions. However, current mission complexity requires the determination of emergent behaviors, as well as time requirements, and safety levels of complicated space exploration architectures, which current analysis methods in use cannot address. To that end, a newer technique has been developed—System Operability Dependency Analysis (SODA). …
Localized Strain And Associated Failure Of Structural Materials,
2018
Purdue University
Localized Strain And Associated Failure Of Structural Materials, Hayden N. Hermes, Andrea Nicolas, Michael Sangid, Noelle C. Easter, James T. Burns
The Summer Undergraduate Research Fellowship (SURF) Symposium
Aircraft are made primarily out of strong and lightweight aluminum alloys, which are relatively low cost, easy to produce, and have allowed for several innovations in the airplane industry. Even though these alloys are highly corrosion resistant, they are susceptible to failure since airplanes experience some of the harshest fatigue and corrosion conditions. Predicting the location of crack initiation on these corroded materials could lead to preventative safety of aluminum components on an aircraft. To study the mechanisms leading to cracking, precorroded AA7050 samples were fatigue loaded to failure, virtually reconstructed form post-mortem characterizations, and modeled accordingly to obtain the …
Multi-Physics Design Optimization Of 2d And Advanced Heterogenous 3d Integrated Circuits,
2018
University of Texas at Arlington
Multi-Physics Design Optimization Of 2d And Advanced Heterogenous 3d Integrated Circuits, Pavan Rajmane
Mechanical and Aerospace Engineering Dissertations - Archive
The convergence and miniaturization of computing and communications dictate building up rather than out. As planar device miniaturization continues to its ultimate limits, the complexity of circuit interconnections for 2-D devices becomes a limitation for performance and drives up power dissipation [1]. 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. In this study, an attempt is made to analyze 3 types of packages i.e. Wafer Level Chip Scale Package (WCSP), Quad Flat No-Lead (QFN) Package and 2-Die …
A Framework For Optimal Path Planning And Nonlinear Guidance For Autonomous Mobile Robots,
2018
University of Texas at Arlington
A Framework For Optimal Path Planning And Nonlinear Guidance For Autonomous Mobile Robots, Paul A. Quillen
Mechanical and Aerospace Engineering Dissertations - Archive
The purpose of this research is to investigate methods and technology for enhancing autonomous capabilities for mobile robots. The measures of autonomy which are specifically covered in this dissertation pertain to a mobile robot’s ability to make decisions and act, in other words guidance and control. This dissertation puts forth a framework using optimal path planning and nonlinear guidance techniques to address these matters. The path plans are synthesized using a numerical navigation function algorithm that will form its potential contour levels based on the “minimum control effort” of the system. Additionally, extensions of the path planning algorithm in the …
Numerical And Experimental Study Of Single Phase And Multiphase Droplet Dynamics On Electrowetting-On-Dielectrode Digital Micro-Fluidics,
2018
University of Texas at Arlington
Numerical And Experimental Study Of Single Phase And Multiphase Droplet Dynamics On Electrowetting-On-Dielectrode Digital Micro-Fluidics, Mun Mun Nahar
Mechanical and Aerospace Engineering Dissertations - Archive
In the recent years, significant efforts have been devoted to the development of droplet based lab-on-a-chip devices of which advantages include being programmable and reconfigurable. Among various droplet flow based microsystems [1-5], electrowetting on dielectric (EWOD) digital microfluidics has many advantages, such as rapid switching response, no joule heating, no need for moving parts like pumps and valves, and most importantly low power requirement [6]. Basic droplet handling techniques - droplet dispensing, transporting, merging and splitting - can be done by sequentially activating and deactivating specific electrodes, which allows to address each droplet individually and to perform various unit processes …
A Multiphysics Study Of Interfacial Properties Of 3d Printed Filaments,
2018
University of Texas at Arlington
A Multiphysics Study Of Interfacial Properties Of 3d Printed Filaments, Alireza Rezaee
Mechanical and Aerospace Engineering Dissertations - Archive
Fused Deposition Modeling has become the most popular 3-D printing method over the last decade. Due to its potential to save time, cost and, labor, there is a great deal of interest to use this technique for production of functional load carrying parts and assemblies in bio-medical, automotive, aerospace, and oil and gas industries. In general, materials used in FDM process are isotropic; however, parts printed using FDM process show anisotropic mechanical properties with inconsistent properties in the transverse direction to the filaments’ cross-section. This anisotropic behavior is due to the fabrication process, and the inconsistency in the transverse mechanical …
Characterizing Contamination To Expand Ashrae Envelope In Airside Economization And Thermal And Reliability In Immersion Cooling Of Data Centers,
2018
University of Texas at Arlington
Characterizing Contamination To Expand Ashrae Envelope In Airside Economization And Thermal And Reliability In Immersion Cooling Of Data Centers, Jimil Manojbhai Shah
Mechanical and Aerospace Engineering Dissertations - Archive
The Datacom facility which comprises rooms or closets used for communication, computers/servers or electronic equipment requires cooling unit which consumes 31% (23% HVAC cooling + 8% HVAC fans) of overall energy. The ASHRAE TC9.9 subcommittee, on Mission Critical Facilities, Data Centers, Technology Spaces, and Electronic Equipment, has suited the data center’s executives by permitting brief period outings of the environmental conditions outside the prescribed temperature-humidity range, into passable extents A1-A3. To comprehend the expanding server densities and the required cooling vitality costs, data center operators are falling back on cost cutting measures. For instance, they are not firmly controlling the …
Woods Tire Model,
2018
University of Texas at Arlington
Woods Tire Model, Priyank Vasant Nandu
Mechanical and Aerospace Engineering Theses - Archive
The performance of a racecar in a maneuver is almost totally determined by the characteristics of the tires and the suspension setup. If the suspension is properly tuned for the maneuver, then the limiting factor is the tire. Therefore, any racecar design and performance analysis must start with a full description of the performance of the tire [1]. Mathematical models for tire performance such as the Pacejka model have been in use for a long time and have become the standard for expressing how a tire will perform dynamically. It comprises of curve fit to experimental data and requires about …
Design Survey Of Laminated Composite I-Beam,
2018
Utah State University
Design Survey Of Laminated Composite I-Beam, Mrinmoy Saha
All Graduate Plan B and other Reports, Spring 1920 to Spring 2023
Composite I-beams are popular for high-strength low-weight applications. Learning the macro-mechanics and designing the composite I-beam properly are necessary. In this report, a design overview of the composite I-beam is discussed which is based on classical lamination theory where it includes the homogenization approach, the plane stress assumption and the Kirchhoff hypothesis. Using these assumptions, a method was developed to come up with the effective material properties of a beam. Formulas to calculate maximum deflection and maximum bending stress and shear stress and the stress concentration at the connection of web-flange are discussed which describe ways for designing and manufacturing …
Investigation Of Thermo-Physical Property Enhancement Mechanism Of Molten Salt Nano-Eutectic Via Nanostructural Change And Polyalphaolefin Nanofluid Via In Situ Formation Of Superstructures,
2018
University of Texas at Arlington
Investigation Of Thermo-Physical Property Enhancement Mechanism Of Molten Salt Nano-Eutectic Via Nanostructural Change And Polyalphaolefin Nanofluid Via In Situ Formation Of Superstructures, Zahra Pournorouz
Mechanical and Aerospace Engineering Dissertations - Archive
For many years, scientists enhanced the specific heat capacity of molten salt nanofluids by dispersing only minute concentrations of different nanoparticles (e.g., 1 wt.%). While the specific heat capacity for molten salts was enhanced in many types of research, other engineering fluids (i.e., water, ethylene glycol, oil) showed decreased specific heat capacity with doping the nanoparticles. Recently, researchers discovered that a unique nanostructure formed by molten salt molecules, which were doped and interacted with nanoparticles, were the reason for enhanced specific heat capacity. Therefore, the enhanced specific heat capacity only happens for molten salts rather than other fluids that may …
Wireless Antenna Sensors For Boiler Condition Monitoring,
2018
University of Texas at Arlington
Wireless Antenna Sensors For Boiler Condition Monitoring, Franck Tchafa
Mechanical and Aerospace Engineering Dissertations - Archive
Structural Health Monitoring (SHM) is a vital technology that implements real-time condition monitoring or damage detection mechanisms for the safety assurance of structural systems such as power stations, aircrafts, bridges, dams, buildings, large machinery, and more. Without proper and timely maintenance, mechanical systems are prone to failures since they experience detrimental factors such as harsh environments, excessive loads, and vibrations. Several sensing technologies exist for SHM applications. Patch antennas are among the list of these technologies, and they are an attractive choice due to their compact size, light weight, ease of manufacturing, and low fabrication cost. Patch antennas have been …
The Development And Validation Of Sinatra: A Three-Dimensional Direct Simulation Monte Carlo (Dsmc) Code Written In Object-Oriented C++ And Performed On Cartesian Grids,
2018
California Polytechnic State University, San Luis Obispo
The Development And Validation Of Sinatra: A Three-Dimensional Direct Simulation Monte Carlo (Dsmc) Code Written In Object-Oriented C++ And Performed On Cartesian Grids, David Matthew Galvez
Master's Theses
The field of Computational Fluid Dynamics (CFD) primarily involves the approximation of the Navier-Stokes equations. However, these equations are only valid when the flow is considered continuous such that molecular interactions are abundant and predictable. The Knudsen number, $Kn$, which is defined as the ratio of the flow's mean free path, $\lambda$, to some characteristic length, $L$, quantifies the continuity of any flow, and when this parameter is large enough, alternative methods must be employed to simulate gases. The Direct Simulation Monte Carlo (DSMC) method is one which simulates rarefied gas flows by directly simulating the particles that compose the …
Fast Prediction Of Thermal Distortion In Metal Powder Bed Fusion Additive Manufacturing: Part 1, A Thermal Circuit Network Model,
2018
Missouri University of Science and Technology
Fast Prediction Of Thermal Distortion In Metal Powder Bed Fusion Additive Manufacturing: Part 1, A Thermal Circuit Network Model, Hao Peng, Morteza Ghasri-Khouzani, Shan Gong, Ross Attardo, Pierre Ostiguy, Bernice Aboud Gatrell, Joseph Budzinski, Charles Tomonto, Joel Neidig, M. Ravi Shankar, Richard Billo, David B. Go, David Hoelzle
Mechanical and Aerospace Engineering Faculty Research & Creative Works
The additive manufacturing (AM) process metal powder bed fusion (PBF) can quickly produce complex parts with mechanical properties comparable to wrought materials. However, thermal stress accumulated during PBF induces part distortion, potentially yielding parts out of specification and frequently process failure. This manuscript is the first of two companion manuscripts that introduce a computationally efficient distortion and stress prediction algorithm that is designed to drastically reduce compute time when integrated in to a process design optimization routine. In this first manuscript, we introduce a thermal circuit network (TCN) model to estimate the part temperature history during PBF, a major computational …
Fast Prediction Of Thermal Distortion In Metal Powder Bed Fusion Additive Manufacturing: Part 2, A Quasi-Static Thermo-Mechanical Model,
2018
Missouri University of Science and Technology
Fast Prediction Of Thermal Distortion In Metal Powder Bed Fusion Additive Manufacturing: Part 2, A Quasi-Static Thermo-Mechanical Model, Hao Peng, Morteza Ghasri-Khouzani, Shan Gong, Ross Attardo, Pierre Ostiguy, Ronald B. Rogge, Bernice Aboud Gatrell, Joseph Budzinski, Charles Tomonto, Joel Neidig, M. Ravi Shankar, Richard Billo, David B. Go, David Hoelzle
Mechanical and Aerospace Engineering Faculty Research & Creative Works
The additive manufacturing (AM) process metal powder bed fusion (PBF) can quickly produce complex parts with mechanical properties comparable to that of wrought materials. However, thermal stress accumulated during Metal PBF may induce part distortion and even cause failure of the entire process. This manuscript is the second part of two companion manuscripts that collectively present a part-scale simulation method for fast prediction of thermal distortion in Metal PBF. The first part provides a fast prediction of the temperature history in the part via a thermal circuit network (TCN) model. This second part uses the temperature history from the TCN …
Shape Optimization Of A Fan Duncte For A Vertical Takeoff And Landing,
2018
University of Texas at Arlington
Shape Optimization Of A Fan Duncte For A Vertical Takeoff And Landing, Jie Hua
Mechanical and Aerospace Engineering Theses - Archive
The popularity of ride sharing services and recent improvements in electric car performance and automation have sparked interest in E-VTOL (Electric Vertical Takeoff and Landing) aircraft for personal transportation. Companies such as Uber, Airbus and EHANG are currently researching such aircraft for transportation over short distances in crowded urban environments. A personal E-VTOL design based on a ducted fan concept is proposed and the vertical lift capability is optimized. A numerical optimization algorithm is coupled with a computational fluid dynamics (CFD) analysis code to perform shape optimization. The objective is to determine the internal and external duct shape that maximizes …
A Study Of Effect Of Bond Length On Bond Strength Using Transient Heat Transfer Analysis,
2018
University of Texas at Arlington
A Study Of Effect Of Bond Length On Bond Strength Using Transient Heat Transfer Analysis, Junaid Mohamed Baig
Mechanical and Aerospace Engineering Theses - Archive
It is important to understand the mechanical properties of the bonding between the adjacent layers of 3D printed parts build by fused deposition modeling. The bonding process is highly nonlinear and depends on various geometrical and thermal process parameters. This work aims to quantify the degree of bonding by calculating bond potential between the extruded layers using finite element heat transfer analysis. Successive transient analysis were carried out using this model by constantly updating the boundary conditions and geometric model during the deposition of the extruded bead. Temperatures at critical points were calculated over a period to calculate the bond …
Inverse Analysis Of Heat Generating Body For Safety Applications,
2018
University of Texas at Arlington
Inverse Analysis Of Heat Generating Body For Safety Applications, Sandeep Patil
Mechanical and Aerospace Engineering Dissertations - Archive
Inverse thermal analysis and its applications have been applied to numerous fields of science and engineering. Historically during the 1950's and early 1960's, space programs played a significant role in the advancement of solution techniques for Inverse Heat transfer Problems(IHTP). It was applied to measure the surface temperature of thermal shield of a space vehicle during its re-entry into atmosphere. Inverse analysis was also used in the estimation of thermo-physical properties of the shield at high operating temperatures. Besides thermal application, inverse technique was also used in other engineering applications such as estimation of alloy specification, design of a shape …
Optimization Of Board Level Reliability Of Microelectronic Packages And Modules,
2018
University of Texas at Arlington
Optimization Of Board Level Reliability Of Microelectronic Packages And Modules, Alok Kumar Lohia
Mechanical and Aerospace Engineering Dissertations - Archive
Thermo-mechanical reliability estimation of electronic packages and modules provides an opportunity to predict the function life of semiconductor devices. The problem complexity lies in the fact that there are variety of electronic packages with different form factors, materials and manufacturing technology for various applications. The custom PCB ranges from very thin for portable application to very thick for power application. Despite conventional understanding and prior studies, some of the failures were not explained. This study reviews three failure problems for QFN, WCSP and BGA packages by characterizing the properties of custom PCB materials by layer removal process. Due to layup …
