Engineering Commons^™

Advanced Air Mobility (Aam) Is Coming To A Town Near You...Are You Ready?, Sarah Nilsson

Publications

This briefing provides a high and low altitude view of what is coming in the way of Advanced Air Mobility (AAM) innovation. It is meant for county, town, or city officials; tribal governments; local businesspersons; airport, heliport, Fixed Base Operator (FBO), flight schools’ owners/operators; and other individuals; who wish to capitalize on, and prepare for, a US industry expected to hit around USD 68 Billion by 2032. Is your community or organization prepared for this new economy? Are your customers, or constituents accepting of these new technologies? Are you ready to capitalize on this AAM market and all the growth …

Pig Butchering In Cybersecurity: A Modern Social Engineering Threat, Sharon L. Burton, Pamela D. Moore

Publications

Pig butchering is an escalating cybersecurity threat that exploits social engineering to build trust and execute financial fraud. The relevance of this research problem lies in the growing incidence and sophistication of these scams, which have severe financial and psychological impacts on victims. The main purpose of this research is to uncover the methods used in pig butchering scams and their impact on individuals and businesses. The research focuses on digital platforms such as social media, dating apps, and professional networking sites, chosen for their wide user bases and the ease of establishing personal connections. The study period encompasses recent …

Assessing Safety Culture: Lessons From The Aviation Industry, Mirrette Gendi, Cheri L. Marcham, Michael O'Toole

Publications

SAFETY CULTURE has been a topic of debate in academia as much as it has been in the practice of various industries (Zohar, 2010). Although the concept and definition of safety culture and what it entails have consumed much of the debate, the assessment of safety culture has been the most controversial. Yet, on the academic level, the topic of monitoring and measuring safety culture has seen limited research that offers reliable and valid assessment tools (Goodheart & Smith, 2014), especially when compared to the importance of safety culture as a component of a safety management system (SMS).

Fly Like A Naval Aviator: Effect Of Procedural Angle-Of-Attack Training On Pilot Comprehension And Decision-Making In General Aviation, Tara Samuels

Doctoral Dissertations and Master's Theses

To make life-saving equipment more accessible to general aviation (GA) aircraft owners and operators, the FAA streamlined installation of angle of attack (AOA) systems in GA fleets. Yet studies suggest GA pilots are ill-equipped to use these systems without training. Pilot performance suffers when an AOA is added to the flight deck because pilots’ knowledge with these systems is merely declarative (know-what) and not sufficiently procedural (know-how). Furthermore, GA pilots struggle to integrate the indicator into their existing (and well-rehearsed) mental models.

The study used a two-way mixed-design analysis of variance with a within-between- subjects approach to examine the effect …

Assessing The Influences Of Electronic Flight Bags On General Aviation Single Pilots’ Situation Awareness In Various Conditions, Dongguang Yu

Doctoral Dissertations and Master's Theses

The widespread adoption of Electronic Flight Bags (EFBs) among general aviation pilots prompts safety concerns regarding transitioning from traditional, heavily loaded paper-based flight bags. However, studies evaluating the impact of EFBs on general aviation pilots’ situation awareness are limited. This study aimed to determine whether EFBs enhanced or hindered general aviation pilots’ situation awareness.

The research compared EFBs with traditional paper-based flight bags to investigate pilots’ situation awareness in a single-pilot flight deck under visual flight rules, normal and emergency flight scenarios, and different mounting positions. A sample of 38 participants was recruited, including flight students, flight instructors, and retired …

In-Situ Characterization And Machine Learning Applications For Composite Processing, Pragathi Agraharam Chan

Doctoral Dissertations and Master's Theses

Numerous aircraft and spacecrafts utilize carbon fiber-reinforced polymer structures to significantly enhance their operational efficiency and overall performance. Autoclave composite processing offers a solution for the intricate design of complex structures. However, the rapid temperature and strain fluctuations experienced during the processing gives rise to a multitude of defects and residual stresses in the composite. In this study, we have devised an in-situ methodology that leverages Digital Image Correlation (DIC) and Machine Learning Applications to effectively observe and track defect deformations occurring throughout the process. This process presents a dataset derived from the curing process of 40 carbon fiber-reinforced polymer …

Ridds: Removal Of Irregular Debris Using Double Nets, Kayann Coote

Doctoral Dissertations and Master's Theses

The quantity of debris in Earth’s orbit is increasing at an alarming rate, and without a sustainable solution, this will detriment the space environment, impacting the future of space travel and space traffic management. While numerous debris removal concepts and designs have been proposed, very few have made it to actual flight tests, and none can remove debris at a fast enough rate to stop debris growth. For debris currently in orbit, most proposed systems are costly on a large scale and cannot adapt to the wide variety of debris shape and geometry and tumbling. The purpose of the proposed …

Model Predictive Control For Autonomous Landing In Complex Scenarios, Konstantinos Sotirakos

Doctoral Dissertations and Master's Theses

The autonomous flight industry is ever-expanding and continuing to push the boundaries of what is possible within the limitations of technology. Multiple companies are exploring the use of autonomous flight for intra-city travel with air taxi services and package delivery vehicles. Other companies are exploring the use of autonomous vehicles for military applications, such as Sikorsky with a next generation Black Hawk helicopter to ensure the safety of soldiers in high threat or altogether dangerous scenarios. In this thesis model predictive control (MPC) algorithms are developed to enable a quadcopter to operate and land autonomously in challenging environments. Specifically, MPC …

Assessing The Impact Of Femur Morphological Variations On Pediatric Hip Joint Biomechanics Using Statistical Shape Modeling, Tamara Chambers

Doctoral Dissertations and Master's Theses

This dissertation aimed to (1) quantify morphological variations in the pediatric hip joint and (2) evaluate the sensitivity of an infant musculoskeletal model (MSM) to these variations, considering hip joint center estimation errors. A shape statistical model (SSM) of decedent infant femurs from the Ortolani collection was created using ShapeWorks, capturing key morphological features, such as variations in the femoral neck-shaft and anteversion angles. Seven synthetic femurs were generated from the SSM to create SSM-informed MSMs, which were systematically evaluated through kinematics and kinetics analyses in OpenSim. Incorporating the SSM led to slight changes in the pediatric MSMs’ kinematics but …

Durability Assessment And Service Life Prediction Of Concrete In Extreme Aggressive Environment, Mohamed Ismail

Doctoral Dissertations and Master's Theses

The objective of this research is to enhance the durability of newly constructed structural elements by assessing the performance of various concrete mixes for chloride resistance. The study focuses on establishing and developing correlations between chloride diffusion rates and concrete resistivity. By identifying these correlations and based on the target service life, the research aims to set appropriate thresholds for Surface Resistivity (SR) and Bulk Resistivity (BR) tests, which will be used to qualify concrete mixes used in in extremely aggressive chloride environments. To achieve these objectives, the research uses a systematic approach that combines experimental testing with analytical modeling. …

Dynamic Estimation Of Large-Scale Flow Events In Open Cavity Flows, Alexandre Mota

Doctoral Dissertations and Master's Theses

Flow over an open cavity has a dynamically complex flowfield, generating pressure fluctuations that can amplify shear stress and cause structural damage to the stores within it and the aircraft as a whole. These pressure loads are linked to large-scale resonant shear layer phenomena. Consequently, it is crucial to establish this link by characterizing the large-scale flow events conditional upon pressure measurements to improve the prediction and control of the detrimental pressure fluctuations. In this study, a link between the pressure measurements (to control) and large-scale shear layer events (to actuate) will be established using a combination of two data-driven …

Adaptive Control And Estimation Of The Center Of Mass Of A 5-Degree-Of-Freedom Spacecraft Testbed, Pol Fontdegloria Balaguer

Doctoral Dissertations and Master's Theses

In space applications, on-ground experimentation is an essential step in control algorithm validation before real mission application. However, on-ground conditions greatly differ from space ones, where satellites operate under extremely low gravity and friction conditions. A common way to simulate these conditions is with air-bearing-based testbeds. These testbeds reduce friction significantly to almost space-like conditions. Air-bearing technology can provide virtually frictionless translational and rotational motion. However, when frictionless rotational motion is achieved, the testbed becomes highly sensible gravity torque. This external torque is produced by the offset between the predetermined geometrical center of rotation (CoR) and the center …

Contributions To The Understanding Of Turbulent Boundary Layers Over Curved Walls, Nicholas Zhu

Doctoral Dissertations and Master's Theses

A wind tunnel campaign was conducted to investigate the DARPA Suboff boundary layer. To emphasize the axisymmetric boundary layer, the generic submarine model's sail, appendages, and propeller were omitted. The study focused on the afterbody from 70–95% of the model length to examine the concurrent pressure gradient and wall curvature effects, which are commonplace in engineering. Three particle image velocimetry (PIV) configurations were employed to measure the boundary layer in detail: one spanned the entire afterbody, another had narrow strips sampled at 16 kHz, and the third used two simultaneous orthogonal measurement planes. Considerable effort was made to reduce the …

Advanced Air Mobility (Aam) Is Coming To A Town Near You...Are You Ready?, Sarah Nilsson

Publications

This briefing provides a high and low altitude view of what is coming in the way of Advanced Air Mobility (AAM) innovation. It is meant for county, town, or city officials; tribal governments; local businesspersons; airport, heliport, Fixed Base Operator (FBO), flight schools’ owners/operators; and other individuals; who wish to capitalize on, and prepare for, a US industry expected to hit around USD 68 Billion by 2032. Is your community or organization prepared for this new economy? Are your customers, or constituents accepting of these new technologies? Are you ready to capitalize on this AAM market and all the growth …

Heat Transfer To Arrays Of Oscillating Impingement Jets, Alex Q. Clay

Doctoral Dissertations and Master's Theses

In gas turbine engines, the desire to increase turbine entry temperatures has become more relevant in order to increase engine efficiency. However, materials used in these engines can only withstand temperatures that are so high. Because of this, the ability to cool hot section components will always limit operating temperatures. Impingement cooling jets have become a common way of cooling due to the high rates of heat transfer that can be achieved. However, previous research has shown that the interaction of impingement jets with cylinder wake can improve the intensity and uniformity of heat transfer. The goal of this study …

Is Declined Cognitive Function Predictive For Fatal Accidents Involving Aging Pilots?, Douglas D. Boyd, Alan J. Stolzer

Publications

Civil aviation comprises airlines/charters and general aviation (GA). Currently, airlines are experiencing a pilot shortage, partly reflecting scheduled retirements mandatory for airline (but not GA) pilots aged 65 years, fueling a debate as to whether the retirement age should be increased. Herein, using 16–40 years-of-age aviators as a reference, we determined whether GA pilots aged 60+ years (i) incurred an elevated accident rate, employing, for the first time, age-tiered flight time as a measure of risk exposure and (ii) carried an excess risk for cognitive deficiency-related fatal accidents. Methods. Airplane accidents (2002–2016) involving Class 3 medical certificated pilots were per …

Bi-Modal Excitation Of A Supersonic Rectangular Jet, Benjamin Malczewski

Doctoral Dissertations and Master's Theses

This work addresses the issue of supersonic rectangular jet noise via bi-modal excitation. A Mach 1.5 heated rectangular jet with a 2:1 aspect ratio is considered. Theoretical work is presented in which a Reduced-Order Model (ROM) is used in conjunction with the Linearized Euler Equations to predict the nonlinear growth and decay of various frequencies due to the interaction between harmonically related modes and the mean flow. Scope is limited to a symmetric disturbance. The case of no interaction is used to help identify a dominant coherent structure, referred to as “f”. For the symmetric disturbance, a Strouhal number of …

Technology Acceptance Of Virtual Reality For Aircraft Maintenance Training, Lusine Carlsson

Doctoral Dissertations and Master's Theses

A study was conducted to investigate Virtual Reality (VR) technology acceptance for aircraft maintenance training by student mechanics. The study employed a survey methodology using the extended Technology Acceptance Model (TAM) as the theoretical framework. Participants were student mechanics from Federal Aviation Administration (FAA) approved aircraft maintenance schools within the United States. The study attempted to address how the variables of perceived usefulness (PU) and perceived ease of use (PEU) influence the students' behavioral intention (BI) to use VR technology for aircraft maintenance training, and how external variables of self-efficacy (SE), perceived enjoyment (PE), perceived health risk (PHR), performance expectancy …

The Role Of Sensing Modalities In Shaping Collective Motion And Group Behavior, Poorendra P. Ramlall

Doctoral Dissertations and Master's Theses

Collective behavior refers to the coordinated movements that emerge from simple interactions between individuals within a group. Traditionally, researchers have modeled these interactions assuming individuals can sense their surroundings in all directions, like having eyes all around their heads. While this is a useful simplification, it does not capture the diverse ways animals actually sense the world. In this thesis, we take inspiration from the natural world, particularly from animals like bats and dolphins that use a combination of hearing and sight to navigate their environments. We explore how combining these sensory cues in a three-dimensional space affects the way …

Space Radiation Assessment And Mitigation: Meeting The Growing Demand For Shielding Solutions By Enhancing Models And Exploring Novel Shielding Opportunities, M. Laura Sorgi Johann

Doctoral Dissertations and Master's Theses

The rapid growth of satellite technology and the increasing presence of vulnerable technology and human life in space have highlighted the need for improved shielding materials. Industry standard protocols for shielding are being pushed to their limits as we gain a deeper understanding of the harsh space environment and as chip sizes approach the scale of radiation wavelengths. Furthermore, the commercialization of space is attracting interest from industries such as pharmaceuticals and semiconductor crystal growing, as they explore the potential benefits of zero-gravity production environments. However, the eagerness to develop lighter shielding and the lack of consideration for existing tools …

Vertiport Ventures: Assessing Operational Feasibility For Evtol Integration In São Paulo’S Helipad And Heliport Infrastructure, Peter E. O'Reilly, Ramy A. Rahimi, Jorge Luiz Rosa Marques, Marco Aurélio Feitosa De A. L. Babadopulos1

Publications

The objective of this study is to assess the operational viability of introducing Electric Vertical Take-Of and Landing (eVTOL) vehicles in São Paulo and its metropolitan area, utilizing existing helipads and helicopter infrastructure. eVTOL aircraft, capable of vertical take-of and landing like helicopters, difer from traditional helicopters in their propulsion systems, with eVTOLs typically featuring multiple smaller electric motor-driven propulsion units instead of internal combustion engines and mechanical transmissions (Schuchardt et al. 2023). The study specifcally targets eVTOLs with the capacity to transport a minimum of four passengers and one pilot for distances of at least 50 km. Appendix provides …

Balloon Borne Gps-Enabled Radiosondes That Enable Simultaneous Multi-Point Atmospheric Sensing With A Single Ground Station, Peter A. Ribbens

Doctoral Dissertations and Master's Theses

Radiosondes are balloon borne atmospheric instruments that are a critical tool for understanding dynamics in the lower layers of the atmosphere. The low-cost radiosondes developed in the Space and Atmospheric Instrumentation Lab have been further developed to improve the system's use as a science-quality atmospheric instrument that is unique in its ability to simultaneously track multiple sondes with a single ground station. Sensors to measure temperature and pressure were added to improve measurements of the atmospheric state. A printed circuit board shield and 3D-printed shell were designed to make mass manufacturing possible. A thermistor-based temperature sensor was developed and tested …

Optimization Of A Plate Beam System For Energy Harvesting Using A Piezoelectric Material, Jose Manuel Almendros Espantaleon

Doctoral Dissertations and Master's Theses

With a continuously growing demand for power, driven by the need to reduce our environmental footprint, this research provides an examination of the potential of energy harvesting with smart materials technology and its practical applications. The energy harvesting system considered here works on generating energy through vibrations of a piezoelectric material beam which will undergo sustained vibrations due to flow of air over its surface. It is assumed that sustained limit cycle oscillations of this system will occur at the flutter velocity. This research creates an optimization framework to obtain the best values of parameters that will result in the …

Exploring A New Conceptual Framework In Aviation Maintenance Incident Reporting Using Natural Language Processing, Christopher P. Braun

Doctoral Dissertations and Master's Theses

In the analysis of human error incidents, human factors specialists predominantly follow two schools of thought in categorization strategies. One is to categorize the operator’s actions by the physical properties of the activity (phenotypes); the other focuses on the cognitive behaviors preceding the incident (genotypes). These categorization strategies are intended to foster an understanding of the events, identify risks, and assist in the implementation of risk reduction interventions. Commercial aviation maintenance presents unique challenges to human factor practitioners in terms of task requirements, working environments, communication modalities, and safety standards. Complex tasks are handed from one shift of personnel to …

Situation Awareness Assessment Of Enhanced Stable Approach Flight Instrument Displays, David J. Hunter

Doctoral Dissertations and Master's Theses

Through the year 2022, runway-related events, including excursions, abnormal runway contact, and runway undershoot and overshoot, were the third leading causes of fatal aircraft accidents. Principal to these runway-related accidents was the presence of an unstable approach. Pilots currently must depend on the timely recall of stable approach criteria stored in long-term memory, application of those criteria against current flight conditions, perception and cognition of deviation from those criteria, and determination of potential courses of action. Such recall is fallible, and challenges to perception and cognition are ever-present.

This study examined whether the presentation of stable approach criteria boundaries and …

Assessing The Impact Of Spacecraft Fragmentation In The Cislunar Region, Marta Lopez Castro

Doctoral Dissertations and Master's Theses

In the last decades, space missions have followed great advancements due to technological improvements and the extensive research developed in the field. Some of these missions are increasingly focusing on satellites orbiting the Moon. The Cislunar region is known to have a higher non-linear chaotic component in the dynamics compared to the low-Earth environment. This research is focused on studying the impact that a satellite explosion has in the Cislunar vicinity. The study is conducted for different periodic orbits that are key destinations for Cislunar traffic. By varying the initial conditions, simulations of explosions at different locations of the orbits …

Studying The Performance Of Object Recognition With Fusion Of Visible Light And Infrared Images With Neural Networks, Plamen Petkov

Doctoral Dissertations and Master's Theses

Neural networks have been used for object detection and recognition in both color and intensity camera images. As the use of infrared cameras, colloquially termed thermal cameras, has increased and costs have decreased, object detection and recognition in infrared camera images have been increasingly studied. An infrared image is treated as an intensity image, just like a grayscale camera image, except the intensity corresponds to infrared radiation instead of visible light. The information provided by these two types of images are different, especially in different lighting and environmental situations, and some types of objects are more easily recognized in visible …

Refinement Of A Regional Storm Surge Mesh For High-Resolution Topographic Representation Of Volusia County, Morgan Harbin

Doctoral Dissertations and Master's Theses

In 2022, Volusia and Flagler Counties of northeast central Florida were impacted indirectly by consecutive Hurricanes Ian and Nicole; the destabilization of dunes and armoring infrastructure caused by Ian left the region susceptible to Hurricane Nicole, which caused unprecedented coastal damage to dunes and seawalls. The extent of damage that occurred within Volusia and Flagler Counties during the 2022 hurricane season, the underrepresentation of this region within sustainability and resilience research, and the ecological, social, and economic value of the geography provide just cause for scientific inquiry of the area’s coastal dynamics. This thesis specifically describes an investigation of Hurricane …

Additively Manufactured Flexible Piezoelectric Wave-Based Multifunctional Sensor, Rishikesh Srinivasaraghavan Govindarajan

Doctoral Dissertations and Master's Theses

The demand for acoustic wave-based sensors has rapidly increased in the aerospace, chemical, gas, and biological fields due to their versatility in sensing measurands. This study aims to develop a flexible piezoelectric sensor exhibiting enhanced piezoelectric properties using additive manufacturing techniques that can detect mechanical strains and gas or volatile organic compounds (VOCs) by incorporating functional material into the sensing layer. This research explores piezoelectric substrate fabrication through diverse additive manufacturing techniques, including new material development made of polymer/nano-fillers with electrodes that are filled using different printing techniques. Notably, the design of the interdigital transducer (IDT) in the piezoelectric sensor …

Sliding Mode Control With Chattering Reduction, Suryamshu Ramesh

Doctoral Dissertations and Master's Theses

Sliding Mode Control is a powerful nonlinear control methodology that can handle parametric uncertainties and external disturbances. However, the discontinuous and high-frequency switching nature of the control law introduces the chattering phenomenon, which leads to potential actuator degradation, alterations to the desired response characteristics and, sometimes, instability during control implementation. The main objective of this thesis is to study Sliding Mode Control with chattering reduction. The Sliding Mode Control law involves an equivalent control component and a discontinuous control component. A disturbance estimation is performed based on Lyapunov analysis and adaptive control techniques and then included in the control law …