Aerospace Engineering Commons^™

Experimental Evaluation Of A Krypton Propellant Arrangement In A T-100-3 Hall-Effect Thruster, Adam Patel, Javier Cortina Fernandez, Justin Chow, Osvaldo Alejandro Martin, Alexey Shashurin

The Summer Undergraduate Research Fellowship (SURF) Symposium

Stationary Hall thrusters are electric, moderate-specific impulse propulsion systems developed in Russia. These devices manipulate electric and magnetic fields to expel ionized gas (plasma) components, resulting in thrust. The success of Hall-effect engines in USSR satellite-transfer missions quickly sparked western interest in the design. Extensive government and academic study commenced shortly after the dissolution of the Soviet Union, when the technology was made available to the United States. The common SPT-100 model was the primary subject of such studies. Unfortunately, limited literature exists for rare and uncommon Hall thruster models. The T-100-3 stationary plasma thruster suffers from this gap; few …

Design Of Selectively Compliant Morphing Wind Turbine Blade Section Using Bistable Laminate For Passive Load Alleviation, Abhishek Chopra, Dr. Andres Arrieta, Janav Udani, Jose Rivas Padilla

The Summer Undergraduate Research Fellowship (SURF) Symposium

The design of passively controlled compliant morphing structures for large scale wind turbine blades has been of interest due to the inherent advantages of lower mass and reduced complexity over their active counterparts. Previous studies have indicated that embedding a locally bi-stable element within the turbine blade section successfully allows for achieving passive load alleviation. The embedded bi-stable member switches from one stable state to another at a critical aerodynamic load. This local structural change results in a global shift in the aeroelastic response of the blade section. Building on these preliminary results, this research investigates a two- dimensional wind …

Characterization And Modeling Of Discontinuous Fiber Composites, Kenneth M. Serrano Rodriguez, Imad Hanhan, Ronald F. Agyei, Michael Sangid

The Summer Undergraduate Research Fellowship (SURF) Symposium

Composite materials, which are light and strong, are of great interest to engineers in the aerospace industry. Specifically in this work, a discontinuous short fiber reinforced polymer composite whose matrix is Polypropylene and fibers are Electric-glass oriented in different directions was studied. The performance of this material is highly dependent on its microstructure, and therefore the objective of this research is to non-destructively characterize the microstructure of the composite material. This includes characterization of its fiber orientation and length, fiber volume fraction, and void volume fraction. To do this, X-ray micro-computed tomography has been used, providing two dimensional cross-sectional images …

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, 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, 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, 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, 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, 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, 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, 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, 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, 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 …

Decomposition And Ionization Of Ionic Liquids, Forrest Grady Kidd Iii

Dissertations

The United States Air Force is interested in developing a situationally responsive space environment. In order to achieve this, dual-mode-propulsion will be utilized. A new class of propellants is being developed for this application based on energetic ionic liquids. Two ionic liquids of current interest are Hydroxylammonium Nitrate (HAN) and Hydroxyethylhydrazinium Nitrate (HEHN) due to their beneficial performance characteristics. The decomposition and ionization chemistry of these two species is investigated in this work. Using GAUSSIAN09 software, reactions with important radicals are explored through quantum chemistry. The energetics of reactions as well as the identity of key product complexes are given. …

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, 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 …

Plume Contamination Measurements Of An Additively-Printed Gox/Abs Hybrid Thruster, David A. Brewer

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This thesis examines the impact of the physical contamination on optical surfaces of spacecraft by an ABS/GOX thruster. Plume contamination presents a significant operational hazard for spacecraft solar arrays and thermal control surfaces can lead to decreased power production and increased spacecraft temperatures. Historically, due to the lack of a reliable, on-demand, and multiple-use ignition methodology, hybrid rockets have never been previously considered for in-space propulsion. Recent advancements in hybrid rocket technologies, have made hybrid systems feasible for in space propulsion. However, prior to this study no research had ever been performed with regard to plume contamination effects due to …

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, 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, 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, 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 …

Parametric Study Of Aerodynamic Performance Of An Airfoil With Active Circulation Control Using Leading Edge Embedded Cross-Flow Fan, M.A. Qayyum Mazumder

Doctoral Dissertations and Master's Theses

A concept of a cross-flow fan (CFF) embedded near the leading edge of an airfoil to actively control the boundary layer for lift and thrust enhancement has been proposed. The design places a cross-flow fan near the leading edge of an airfoil and flow is drawn in from the pressure side of the airfoil, energized and expelled out to the suction side near the leading edge. This CFF system simulates the active boundary layer control by blowing commercial computational fluid dynamics (CFD) code ANSYS Fluent is employed to perform 2-D calculations based on various parameters of the CFF and compared …

Development To A Flexible Surface Acoustic Wave Sensor For Strain Sensing, Neha Vedavathi Ramachandran

Doctoral Dissertations and Master's Theses

Surface acoustic wave (SAW) sensors have increasing demand in structural health monitoring due to their passive, variable bandwidth, reliable life-cycle, high accuracy, small size, and light nature. SAW sensors can not only provide the static states of the structural system, such as temperature and pressure but also enable continuous real-time monitoring of dynamic states including strains. SAW sensors are generally fabricated with a rigid piezoceramic substrate, incapable of adapting to highly curved surfaces or flexible objects. The ongoing demands of sensor adaptability with flexible substrates, which is also capable of wireless monitoring, is the basis of the research that can …

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 …

Biofidelic Piezoresistive Sandwich Composites, Nengda Jiang

Doctoral Dissertations and Master's Theses

Silicone based biofidelic surrogates are being used in many biomedical applications; e.g. to understand the body injury mechanisms, evaluate protective equipment like helmets and armors. Apart from matching the mechanical behavior of bodily tissues, there is an increasing requirement for these materials to be electrically conductive and piezoresistive to facilitate direct instrumentation. Carbon nanotubes (CNTs) are a possible filler to impart electrical conductivity and piezoresistivity to silicone biofidelic materials. A sandwich structure of silicone and CNT sheet, comprising two dielectric facesheets and a highly conductive core layer has added advantages of raising the dielectric permittivity and suppressing dielectric loss.

In …

Determination Of Takeoff And Landing Distances Using An Ipad Performance Application For The Diamond Da40, Tyler A. Babb, Christina Hiers

International Journal of Aviation, Aeronautics, and Aerospace

All pilots are required to calculate aircraft performance parameters prior to flight. This includes takeoff and landing distances. Traditionally, pilots in training have planned for takeoff and landing performance using paper charts provided by the manufacturer. However, professional pilots use devices such as Flight Management Systems (FMS), Electronic Flight Bag (EFB) applications, or on-board performance computers (OPC) to make such calculations. During primary flight training, student pilots could make performance calculations with proper software, similar to the method they will typically use at the professional level. Recently an iPad application was released which can calculate numerous performance parameters for specific …

High Dynamic Range Optical Devices And Applications., Elijah Robert Jensen

Electronic Theses and Dissertations

Much of what we know about fundamental physical law and the universe derives from observations and measurements using optical methods. The passive use of the electromagnetic spectrum can be the best way of studying physical phenomenon in general with minimal disturbance of the system in the process. While for many applications ambient visible light is sufficient, light outside of the visible range may convey more information. The signals of interest are also often a small fraction of the background, and their changes occur on time scales so quickly that they are visually imperceptible. This thesis reports techniques and technologies developed …

Experiments Of Propeller-Induced Flow Effects On A Low-Reynolds-Number Wing, Gavin K. Ananda, Robert Deters, Michael S. Selig

Publications

Novel findings are discussed in this paper that will be especially beneficial to designers and modelers of small-scale unmanned air vehicles and high-altitude long-endurance vehicles that both operate at low Reynolds numbers (Re = 50,000-300,000). Propeller-induced Oow effects in both tractor and pusher configurations on a recta ngular wing using the Wortmann FX 63-137 airfoil (a common low-Reynolds-number high-lift airfoil) are presented in this paper . Significant performance benefits can be found for a wing in the tractor configuration. Experiments, including trip tests and upper-surface oil Dow visualization, show and verify that the propeller slipstream induces early transition to turbulent …

Command Governor-Based Adaptive Control For Dynamical Systems With Matched And Unmatched Uncertainties, Metehan Yayla, Ehsan Arabi, Ali Turker Kutay, Tansel Yucelen

Mechanical and Aerospace Engineering Faculty Research & Creative Works

In this paper, we propose a command governor-based adaptive control architecture for stabilizing uncertain dynamical systems with not only matched but also unmatched uncertainties and achieving the desired command following performance of a user-defined subset of the accessible states. In our proposed solution, online least-squares solutions for the matched and unmatched parameters are obtained through integration method and they are employed in the adaptive control framework. Specifically, the matched uncertainty is identified and its effect upon the system behavior is entirely attenuated. Moreover, using the unmatched uncertainty approximation obtained through radial basis function neural networks, the command governor signal is …

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 …