AE Doctoral Dissertation 2017-2018

A collage of photos of G.T.A.E. Ph.D. grads from commencement
Each year, the Daniel Guggenheim School of Aerospace Engineering graduates between 30 and 40 doctoral students - each with unique contributions to make in research, academia, industry, and the evolution of the discipline itself. On this page, we provide links to their abstracts and their published dissertations. 

2017 - 2018 Doctoral Dissertations

Takuma Nakamura: "Multiple-Hypothesis Vision-Based Landing Autonomy" ( Advisor: Prof. Eric N. Johnson)

Tech TowerUnmanned aerial vehicles (UAVs) need humans in the mission loop for many tasks, and landing is one of the tasks that typically involves a human pilot. This is because of the complexity of a maneuver itself and flight-critical factors such as recognition of a landing zone, collision avoidance, assessment of landing sites, and decision to abort the maneuver. read the abstract (pdf)

Alexandra C. Long: "Passively Stable Pyramid Sail to Deorbit Small Satellites" (Advisor: Prof. David Spencer)

Tech TowerOrbital debris is a growing problem in low-Earth orbit, especially with a number of commercial companies intending to launch hundreds to thousands of micro-satellites into this regime with the goal of providing global internet service. The main goal of this research is to create a standardized, bolt-on system that will passively deorbit a small satellite from low-Earth orbit within 25 years to reduce the probability of collision with other objects and creating new debris. read the dissertation

Shane Lympany: "Acoustic Damping Mechanisms of Half-Wave Resonators with Applications to Rocket Engine Combustion Instabilities" (Advisor: Prof. Krishan K. Ahuja)

Shane LympanyCombustion instabilities in rocket engines are caused by coupling between the combustion processes and pressure oscillations in a combustor, and they are characterized by the frequencies and shapes of the acoustic modes of the combustion chamber. Acoustic resonators are commonly installed in combustors to provide passive acoustic damping and prevent combustion instabilities. read the dissertation

Leah Ruckle: "Approaches to Solving the Express Shipment Service Network Design Problem" (Advisor: Prof. Dimitri Mavris)

Leah Ruckle

Express shipment, the delivery of same-day, overnight and two-day packages, is a multi-billion dollar industry in the United States and abroad. It has become an essential part of business operations and, with the rise of e-commerce, an expectation of the everyday consumer. read the dissertation

Peter Z. Schulte: "A State Machine Architecture for Aerospace Vehicle Fault Protection" (Advisor: Prof. David Spencer

Peter SchulteBecause of their complexity and the unforgiving environment in which they operate, aerospace vehicles are vulnerable to mission-critical failures. In order to prevent these failures, aerospace vehicles often employ Fault Detection, Isolation, and Recovery (FDIR) systems to sense, identify the source of, and recover from faults. read the dissertation

Ju Hyun Kim: "A Methodology for Forecasting Impact of Demand Response on Capacity Expansion Planning" (Advisor: Prof. Dimitri N. Mavris)

Tech TowerIn parallel to tighter energy regulations and increasing demand for emissions reduction, the Department of Energy (DOE) has set a goal to reduce energy consumption in the building sector to 50% of 2010 levels by 2030. This encourages the use of advanced operational strategies and demand side management concepts to improve energy efficiency and reduce peak energy loads. read the dissertation

Yong-Boon Kong: "Development of a Finite State Coaxial Rotor Dynamic Inflow Model" (Advisor: Prof. J.V.R. Prasad)

Tech TowerAccurate modeling of rotor inflow dynamics in flight simulations is crucial for rotorcraft performance and handling qualities evaluations. While inflow predictions based on momentum theory give good results in hover, they do not produce the accuracy needed in forward flight. High-fidelity models such as free-wake or vortex particle method may not be computationally efficient for use in real-time flight simulations. read the dissertation

Christopher R. McBryde: "Spacecraft Visual Navigation Using Appearance Matching and Multi-Spectral Sensor Fusion" (Advisor: Prof. Glenn Lightsey)

Tech TowerOne of the capabilities necessary for a successful satellite mission is knowledge of its location and orientation in space, especially relative to a target. Relative navigation is an enabling technology for spacecraft formation flying, rendezvous and docking, and hazard avoidance. read the dissertation

Seth Gordon "A Stochastic Agent Approach (SAA) for Mission Effectiveness" (Advisor: Prof. Dimitri Mavris)

Seth Gordon

A process for using stochastic and probabilistic agent decision-making was proposed. This process is employed to conduct a Mission Space Exploration to evaluate a wide assortment of possible matériel and non-matériel solutions to an identified capability gap. read the dissertation

Shiang-Ting Yeh: "Common Proper Orthogonal Decomposition-Based Emulation and System Identification for Model-Based Analysis of Combustion Dynamics" (Advisor: Prof. Vigor Yang)

Tech TowerFor high-performance power generation and propulsion systems, such as those of airbreathing and rocket engines, physical experiments are expensive due to the harsh requirements of operating conditions. In addition, it is difficult to gain insight into the underlying mechanisms of the physiochemical processes involved because of the typical reliance upon optical diagnostics for experimental measurements. read the dissertation

Kevin Garanger: "Introducing the Foundations of a General Framework for Closed-Loop Control in Additive Manufacturing via In Situ Measurements and Semantic Annotations" (Advisor: Prof. Eric Feron)

Tech TowerDuring the last decade, additive manufacturing (AM) has become increasingly popular for rapid prototyping, but has remained relatively marginal beyond the scope of prototyping when it comes to applications with tight tolerance specifications, such as in aerospace. Despite a strong desire to supplant many aerospace structures with printed builds, additive manufacturing has largely remained limited to prototyping, tooling, fixtures, and non-critical components. read the dissertation