Aerospace Engineering Commons^™

Investigation Of A Pressure Wave Supercharger For An Industrial Diesel Engine, Brian A. Beasley

Theses and Dissertations

Internal combustion engines suffer from decreased performance as altitude is in- creased. This performance decrease can be overcome by increasing the pressure in the engine's intake manifold. Typically, this is accomplished with a turbocharger or supercharger. However, mechanical compression devices such as these suffer from decrease compression efficiency as the size of the device decreases. The size of the compression device scales with the amount of mass ow through the device, and the amount of mass ow is proportional to the size of the engine. This means a small turbocharger for a small engine is less efficient than a larger …

Optimal Finite Thrust Guidance Methods For Constrained Satellite Proximity Operations Inspection Maneuvers, Eric R. Prince

Theses and Dissertations

Algorithms are developed to find optimal guidance for an inspector satellite operating nearby a resident space object (RSO). For a non-maneuvering RSO, methods are first developed for a satellite subject to maximum slew rates to conduct an initial inspection of an RSO, where the control variables include the throttle level and direction of the thrust. Second, methods are developed to optimally maneuver a satellite with on/off thrusters into a natural motion circumnavigation or teardrop trajectory, subject to lighting and collision constraints. It is shown that for on/off thrusters, a control sequence can be parameterized to a relatively small amount of …

Satellite Articulation Sensing Using Computer Vision, David H. Curtis

Theses and Dissertations

Autonomous on-orbit satellite servicing benefits from an inspector satellite that can gain as much information as possible about the primary satellite. This includes performance of articulated objects such as solar arrays, antennas, and sensors. A method for building an articulated model from monocular imagery using tracked feature points and the known relative inspection route is developed. Two methods are also developed for tracking the articulation of a satellite in real-time given an articulated model using both tracked feature points and image silhouettes. Performance is evaluated for multiple inspection routes and the effect of inspection route noise is assessed. Additionally, a …

Development And Application Of Quadratic Constitutive Relation And Transitional Crossflow Effects In The Wray-Agarwal Turbulence Model, Hakop Jack Nagapetyan

McKelvey School of Engineering Graduate Student Theses & Dissertations

Computational Fluid Dynamics (CFD) has now become an almost indispensable tool for modern engineering analysis of fluid flow over aircrafts, turbomachinery, automobiles, and many other industrial applications. Accurate prediction of turbulent flows remains a challenging problem. The most popular approach for simulating turbulent flows in complex industrial applications is based on the solution of the Reynolds-Averaged Navier-Stokes (RANS) equations. RANS equations introduce the so called “Reynolds or turbulent stresses” which are generally modeled using the Boussinesq approximation known as “Turbulence modeling.” Despite their development over a century, the turbulence models used with RANS equations still need much improvement. The first …

Clean-Fuel E-Vtol Air Mobility Vehicles For Unmanned And Manned Operations, Larry D. Mccarroll, Brian Morrison, Bruce J. Holmes D.E., Faiaa, Fraes, Henry Vu

National Training Aircraft Symposium (NTAS)

Imagine for a moment, having your very own safe, affordable, clean-fuel, point-to-any point vehicle for travel in the 21st-century 3-dimensional airspace system. Your ultra-reliable e-VTOL allows commuters to leave behind the constraints of hub-and-spoke airports, and the congestion of interstates, turnpikes and freeways. Facilitating Inter- and Intra-urban travel, such as downtown-to-airport, or metropolis-to-metropolis, or home-to-work. Perfect for dense urban environments worldwide. And all while offering the clean power of hydrogen for zero-emission travel.

This vision for efficient, clean, delay-free mobility has been talked about for decades, but always waived aside as some kind of futurist vision. This future requires tackling …

Evaluating The Impact Of Nextgen’S Air Traffic System On Aviation Security, Linda V. Weiland, G. Wei

Publications

Networked Next Generation Air Transportation System (NextGen) opened the gate to digital National Airspace System (NAS) in cyberspace. Air traffic improvements from NextGen system, accompanied by the risk of long-standing cyberattack issue in information technology industry became an increasingly challenging matter to the aviation community and Air Traffic Management (ATM), as cybersecurity challenges in the NextGen system could affect NextGen's principle assurance of safety and security in air transportation. The technological shift of NAS infrastructure from traditional radar-based systems to networking system of systems leads to a review, revision and redefinition of current policies, standards regelations, cultures and norm to …

Quadrotor Swarm Arena (Quasar) Development Of A Swarm Control Testbed, Shane T. Stebler, William Mackunis

Beyond: Undergraduate Research Journal

Swarm control systems are increasingly popular in the robotics industry and academia due to their many potential applications. The goal of the Quadrotor Swarm Arena (QuaSAr) project is to construct a quadrotor swarm control testbed to provide researchers with the tools needed to experimentally investigate this emerging science. This testbed is equipped with a motion capture system, test control station, and numerous quadrotor UAVs. MATLAB-Simulink is utilized for control law development, data processing, and test control. This configuration allows researchers to test developing control law in a 'plug and play' manner as control development and test control are all completed …

An Analysis Of Harmonic Airloads Acting On Helicopter Rotor Blades, Iftekhar A. Riyad

LSU New Orleans Theses and Dissertations

Rotary wing aircrafts in any flight conditions suffer from excessive vibration which makes the passengers feel uncomfortable and causes fatigue failure in the structure. The main sources of vibration are the rotor harmonic airloads which originate primarily from the rapid variation of flow around the blade due to the vortex wake. In this thesis, a mathematical model is developed for rotor blades to compute the harmonic airloads at rotor blades for two flight conditions vertical takeoff and landing, and forward flight. The sectional lift, drag, and pitching moment are computed at a radial blade station for both flight conditions. The …

Remote Sensing Of Soil Moisture Using S-Band Signals Of Opportunity: Model Development And Experimental Validation, Marvin Jesse, Benjamin Nold, James L. Garrison

The Summer Undergraduate Research Fellowship (SURF) Symposium

Root zone soil moisture (RZSM) is a vital aspect in meteorology, hydrology, and agriculture. There are currently some methods in passive and active remote sensing at L-band, but these methods are limited to a sensing depth of approximately 10 cm. Observing RZSM (water in the top meter of soil) will require lower frequencies, thus presenting significant difficulties for a spaceborne instrument, because of the required antenna size, the presence of radio-frequency interference (RFI), and competition for spectrum allocations (in the case of active radar). Bistatic radar using Signal of Opportunity (SoOp) (e.g. digital satellite transmitters) provides an opportunity for remote …

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 …