Engineering Commons^™

Time Optimal State Feedback Control With Application To A Spacecraft With Cold Gas Propulsion, Samuel J. Kitchen-Mckinley, Sergey V. Drakunov

Publications

A cold gas propulsion system is well suited to provide the required thrust for a small surveyor spacecraft operated near an asteroid or planetary surface. The cold gas propellant can obtained in-situ from local surface or atmospheric constituents. For small spacecraft, the cold gas system may be limited to only on-off control of the main tank where the generated thrust is directly dependent on the tank pressure. As such the thrust will slowly decrease as the propellant is expended. A state feedback, time optimal, control law is developed for a vehicle with propellant is expended. A state feedback, time optimal, …

Cruise Missile Integrated Air Defense System Penetration: Modeling The S-400 System, Michael Pelosi, Amie K. Honeycutt

International Journal of Aviation, Aeronautics, and Aerospace

This research determines improved flight-path routes that make maximum utilization of terrain-masking opportunities, and defending radar and missile system equipment performance and launch timing constraints, in order to avoid radar detection and tracking, and to mitigate subsequent missile shoot-down risks. The problem is formulated as one of constrained optimization in three dimensions. Advantageous solutions are identified using the A* Algorithm in conjunction with detailed equipment performance and constraint calculations and high-resolution digital terrain elevation maps. Topographical features in digital terrain are exploited by the algorithm to avoid radar detection and tracking. The model includes provisions for all-aspect/all-frequency radar cross section …

Pilot Training Metrics At A Part 141 University Training Program, Steven Hampton, Dothag Truong, Ken Byrnes, Troy Techau

Publications

The study evaluates training at a collegiate flight training program providing metrics for time and costs from zero time to a Private Pilot. Training times for flights and activities are pulled from a sophisticated database used at Embry-Riddle Aeronautical University (ERAU) and matched with flight and ground school lessons and then further subdivided to determine the amount of time spent training in areas of operation that are prescribed by the Federal Aviation Administration in the published Practical Test Standards and Airman Certification Standards for those seeking pilot licenses and ratings. Provided are mean times and costs for a prospective pilot …

Static Testing Of Propulsion Elements For Small Multirotor Unmanned Aerial Vehicles, Robert W. Deters, S.C. Kleinke, Michael S. Selig

Publications

The growing use of small multirotor aircraft has increased the interest in having better performance results especially with the propulsion system. The size of the propellers used on these aircraft operate at low Reynolds numbers that are typically less than 200,000. Static performance testing of ten propeller pairs (tractor and pusher) were completed and is the beginning of a systematic test of propellers used on multirotor systems. The propellers chosen for this initial set of tests were selected from four popular quadrotors. Besides testing the propellers provided with the aircraft, propellers that are sold as replacements from third-party companies were …

Influence Of Activated Carbon Surface Oxygen Functionality On Elemental Mercury Adsorption From Aqueous Solution, Emily K. Faulconer, David W. Mazyck

Publications

Mercury (Hg), though naturally occurring, is a toxic element. Exposure to various forms of mercury can be harmful for humans and ecosystems. Mercury-contaminated wastewater can be treated using activated carbon to adsorb the mercury, allowing for safe discharge. Wet chemical oxidation of activated carbon was performed to enhanced surface oxygen functionality, with the objective of enhancing aqueous ionic (Hg(II)) and elemental (Hg(0)) mercury adsorption. Characterization of the modified carbons included nitrogen adsorption-desorption, elemental analysis, point of zero charge, and total acidity titration. The concentration and identity of the modifying reagent influenced the characteristics of the carbons, including the surface oxygen …

Understanding Deleted File Decay On Removable Media Using Differential Analysis, James H. Jones Jr, Anurag Srivastava, Josh Mosier, Connor Anderson, Seth Buenafe

Annual ADFSL Conference on Digital Forensics, Security and Law

Digital content created by picture recording devices is often stored internally on the source device, on either embedded or removable media. Such storage media is typically limited in capacity and meant primarily for interim storage of the most recent image files, and these devices are frequently configured to delete older files as necessary to make room for new files. When investigations involve such devices and media, it is sometimes these older deleted files that would be of interest. It is an established fact that deleted file content may persist in part or in its entirety after deletion, and identifying the …

Source Anonymization Of Digital Images: A Counter–Forensic Attack On Prnu Based Source Identification Techniques, Prithviraj Sengupta, Venkata Udaya Sameer, Ruchira Naskar, Ezhil Kalaimannan

Annual ADFSL Conference on Digital Forensics, Security and Law

A lot of photographers and human rights advocates need to hide their identity while sharing their images on the internet. Hence, source–anonymization of digital images has become a critical issue in the present digital age. The current literature contains a number of digital forensic techniques for “source–identification” of digital images, one of the most efficient of them being Photo–Response Non–Uniformity (PRNU) sensor noise pattern based source detection. PRNU noise pattern being unique to every digital camera, such techniques prove to be highly robust way of source–identification. In this paper, we propose a counter–forensic technique to mislead this PRNU sensor noise …

Harnessing Predictive Models For Assisting Network Forensic Investigations Of Dns Tunnels, Irvin Homem, Panagiotis Papapetrou

Annual ADFSL Conference on Digital Forensics, Security and Law

In recent times, DNS tunneling techniques have been used for malicious purposes, however network security mechanisms struggle to detect them. Network forensic analysis has been proven effective, but is slow and effort intensive as Network Forensics Analysis Tools struggle to deal with undocumented or new network tunneling techniques. In this paper, we present a machine learning approach, based on feature subsets of network traffic evidence, to aid forensic analysis through automating the inference of protocols carried within DNS tunneling techniques. We explore four network protocols, namely, HTTP, HTTPS, FTP, and POP3. Three features are extracted from the DNS tunneled traffic: …

An Accidental Discovery Of Iot Botnets And A Method For Investigating Them With A Custom Lua Dissector, Max Gannon, Gary Warner, Arsh Arora

Annual ADFSL Conference on Digital Forensics, Security and Law

This paper presents a case study that occurred while observing peer-to-peer network communications on a botnet monitoring station and shares how tools were developed to discover what ultimately was identified as Mirai and many related IoT DDOS Botnets. The paper explains how researchers developed a customized protocol dissector in Wireshark using the Lua coding language, and how this enabled them to quickly identify new DDOS variants over a five month period of study.

Literature Review: Biomimetic And Conventional Aircraft Wing Tips, Naseeb Ahmed Siddiqui, Waqar Asrar, Erwin Sulaeman

International Journal of Aviation, Aeronautics, and Aerospace

This paper is an attempt to summarize the effect of wing tip devices employed by birds, as well as aeronautical engineers in the past to improve the performance characteristics of aircraft. The focus is on reduction of the induced drag or drag due to lift also known as inviscid drag. This paper will provide an insight on both biomimetic and conventional wing tip approaches to reduce the induced drag. Prior analysis and experiments on the aerodynamics of airplane performance due to both these separate studies have been discussed. The needs of the industry and their past inventions have been described …

Integration Of Macro-Fiber Composite Material On A Low Cost Unmanned Aerial System, May Chong Chan

Doctoral Dissertations and Master's Theses

The development, deployment, and operation of Unmanned Aerial Systems (UAS) have grown exponentially in recent years and have provided researchers with the opportunity to gain hands-on experience with aircraft in a manner that was previously limited to institutions and companies with large budgets. This allows the generation and testing of UAS advanced technologies using low cost systems. The scope of this thesis does not aim to make vast improvements to the control strategy itself, but to expand upon previous UAV work carried out at Embry-Riddle by designing, implementing, and demonstrating a simulation environment for mechanical and Macro-Fiber Composite (MFC) actuated …

Performance Analysis Of A Coaxial Helicopter In Hover And Forward Flight, Stanrich D. Fernandes

Doctoral Dissertations and Master's Theses

The performance of a coaxial rotor system has been analyzed by establishing a proper basis of comparison between a conventional single rotor and coaxial rotor. An attempt has also been made to better understand the complicated aerodynamic interactions associated with coaxial rotor wakes by using a free-vortex methodology (FVM). The FVM is a Lagrangian-based wake convection methodology, which solves for the evolution of the vortical wake produced by the rotor blades under the influence of an external flow. The extent to which the two rotors interact with each other was found to be highly dependent on the inter-rotor spacing. To …

Battery Centric Serial Hybrid Aircraft Performance And Design Space, Lenny Gartenberg

Doctoral Dissertations and Master's Theses

The design space and flight envelope of a battery centric serial hybrid aircraft has been analytically derived. The formulation assumes cruising flight only and all energy available is used. The flight envelope can be generated for any conventional propeller driven serial hybrid aircraft. The advantageous combination of an electric motor and controllable-pitch electric propeller was also explored. The results are used to be able to control efficiency and noise at constant thrust and therefore constant airspeed. Manufacturer provided electric motor and propeller data is used for efficiency purposes. Since the electric motor is virtually silent compared to the propeller, published …

Robust Optimization And Groundwork For Problem Mapping, Leo Austin Ghelarducci

Doctoral Dissertations and Master's Theses

Goals of this research were to develop a conceptual algorithm that can optimize execution time for generating a solution set and demonstrate that a solution set of one sub-problem can be applied to another sub-problem within the same problem set. To achieve the proposed goals, GloPro was developed to generate rule sets for different sub-problems within a problem set, as well as identifying which rule sets are to be utilized for a given instance of the problem. The algorithm was to be robust, as to be applicable to a wide array of problems without radical re-design per problem. This idea …

Structural Design Of A Business Jet Winglet, Jaime Gutierrez

Doctoral Dissertations and Master's Theses

Structural sizing of a winglet for the Falcon 10 was performed and is presented here. The aerodynamic profile of the winglet was taken from a previous study, which predicted an increase in range of 3.3% with an estimated weight increase of 52 kg. An investigation of the current structure layouts and materials used in the industry was conducted. Six loading cases were analyzed to identify the most critical for the winglet, found to be negative and positive sideslip and gust. A finite element model was developed and used to size the structure. A fabrication process and assembly is described and …

Comparison Of Rans Modeling To Dual-Plane Piv Measurements Of The Turbulent Tip Vortex Trailed From A Hovering Rotor, Zachary Lietzau

Doctoral Dissertations and Master's Theses

Numerical simulations using the Reynolds-Averaged Navier-Stokes (RANS) equations were conducted to study the development and turbulent decay of the tip vortices in the wake produced by a hovering rotor. The computational results were compared to detailed, dual plane Particle Image Velocimetry (PIV) measurements of a turbulent tip vortex trailed from a single-bladed rotor. The work investigated both the required mesh resolution and most suitable turbulence closure models with rotational/curvature corrections by assessing their predictions of the tip vortex properties and the overall physical nature of the rotor wake. It was found that even when using a higher-order accurate central differencing …

Electrical Optimization Of A Plug-In Hybrid Electric Vehicle, Andre J. Napier

Doctoral Dissertations and Master's Theses

Hybrid electric vehicles electrification and optimization is a prominent part of today’s automotive industry. GM and the Department of Energy challenge 16 universities across North America to redesign a Chevrolet Camaro into a hybrid electric vehicle. This thesis will address how Embry Riddle Aeronautical University’s EcoCAR team electrified and optimized the vehicle. The objective of the thesis is to optimize the electric portion of the vehicle, particularly the low voltage circuitry. Prior work is discussed in detail on the vehicle communication bus, building the power distribution unit and the approach the electrical team took when building the electric portion of …

Development Of An Emulated Free-Floating Environment For On-Earth Testing Of Space Robots, Narendran Muraleedharan

Doctoral Dissertations and Master's Theses

The ability to perform experiments on space robotic systems within a laboratory setting is crucial to development and testing of satellites and space robots prior to launch. One of the most widely used techniques which recreate the on-orbit motion of space robots and targets is hardware-in-the-loop simulation. This method requires extensive knowledge of the space robot model dynamic parameters. This research proposes a method which uses force feedback to control a robotic platform on which the space robot is mounted. The robotic platform is driven in such a way that the gravity-compensated forces and torques at the mounting interface are …

Extended Surface Heat Transfer Coefficients Via Endwall Temperature Measurements, Yogesh Pai

Doctoral Dissertations and Master's Theses

Short pins are used for internal cooling of the trailing edge in a gas turbine blade. A novel method is described in this thesis which helps in simplifying the experimental process used to obtain average heat transfer data on the pin surface, at the expense of additional post processing complexity. The method is based on a unique, analytical solution of the longitudinal conduction equation with internal heat generation, allowing computation of heat transfer rates via pin base temperature measurements via Temperature Sensitive Paint, or similar non-intrusive methods. Verification of this method is done with comparisons to the solution of infinite …

Ab Initio Computation Of Radiative Properties Of Monatomic Hydrogen, Fanny Thomas

Doctoral Dissertations and Master's Theses

With renewed interest in planetary atmospheric entry, descent, and landing, NASA has noted a need for improved physics modeling in computational fluid dynamics. Uncertainty in experimental data used in radiation heat transfer computations leads to “over-engineering” of entry body heat shields, at large weight and cost penalties. There is interest in developing hypersonic thermophysics models from the known “first principles” of physics.

A method for computing high temperature gas emissivity and absorptivity from quantum mechanics principles is developed. The Schroedinger wave equation is cast as a discretized matrix eigenvalue problem which is solved using the ERAU parallel supercomputer. The numerical …

Applications Of The Technology Acceptance Model To Integration Of The Automatic Ground Collision Avoidance System In Fighter Aircraft Operations, Casey Richardson

Doctoral Dissertations and Master's Theses

The leading cause of F-16 fighter aircraft and fighter pilot losses is ground collisions. In an effort to curb this hazard, an automatic ground collision avoidance system (AGCAS) was formally fielded for use in routine U.S. Air Force active-duty F-16 operations in 2014. AGCAS uses a high-level automation design capable of altering the aircraft’s flight control system independent of pilot action.

This study explored an application of the Technology Acceptance Model (TAM) to integration of the AGCAS in fighter aircraft operations. Using data from a survey of active-duty U.S. Air Force F-16 operational fighter pilots (n=142), collected shortly after initial …

The Effect Of Surface Materials And Morphology On Wingsuit Aerodynamics, Timothy Allen Sestak

Doctoral Dissertations and Master's Theses

This study examines the aerodynamic effects of the materials, textiles, and morphologies currently used in wingsuit design and construction. The experiment was a low-speed wind tunnel investigation using a rigid wing with an aspect ratio of 2, a NACA 4418 airfoil cross section and a smooth, polished painted surface as a baseline. The baseline wing was modified by covering the upper and lower surfaces with various textiles currently used in wingsuit construction. This study is the first step in continued research to design and build a wingsuit with superior glide performance compared to current designs. Surface textures and features on …

The Issues And Complexities Surrounding The Future Of Long Duration Spaceflight, Solomon Miiro

Graduate Student Works

The Comprehensive Exam put forward by this proposal is intended to address the learning objectives covered by the Master of Aeronautical Science Degree with specializations in Aviation Aerospace Safety Systems and some limited aspects in Human Factors in Aviation Systems. This will be accomplished by researching the following topics: effects of long duration spaceflight on crew performance and functioning and the steps that should be taken to enable long term spaceflight mission crews in lieu of accomplishing important missions; a human factor analysis should current human-machine design interfaces be enhanced to make manual rendezvous and docking in space easier to …

Supervisory Controls Strategy To Reduce Utility Factor Weighted Criteria Emissions For A Plug-In Hybrid Electric Vehicle, Thomas Francis Gorgia Iii

Doctoral Dissertations and Master's Theses

Criteria emission reduction techniques are being more sought out in the automotive industry due to current government regulation for light duty vehicles. Parallel-series plug in hybrid electric vehicles can have multiple strategies to balance emissions and fuel consumption. Common controls strategies in industry target fuel economy by using a large electric vehicle range, known as charge depletion, followed by maintaining a state of charge after a specific vehicle threshold, or charge sustaining. A charge preserve strategy works by running an engine at an optimal loading condition, the engine will burn the fuel more complete reducing criteria emissions. Charge preserve will …

Numerical Investigation Of A Phase-Change Material Based Photovoltaic Panel Temperature Regulation System, Rohit Gulati

Doctoral Dissertations and Master's Theses

As the production of clean electricity has gained importance, photovoltaic (PV) panels have become a widely used technology. But, during operation, PV panels heat up due to the solar insolation and suffer a drop in electrical output. The goal of this investigation is to use phase-change materials (PCM) to passively cool PV panels. The PCM is inside an aluminum container attached to the back surface of the PV panel. Four configurations of the container are investigated. The first configuration is a container with bulk PCM occupying its entire interior volume. The depth of this container is varied. The second configuration …

A Spreadsheet For Estimating Soil Water Characteristic Curves (Swcc), Ghada Ellithy

Publications

SWCC can be measured in the lab; however, due to the cost, time, and high variability in the results, empirical equations were developed using multiple regression approaches on databases consisting of a large number of measured SWCCs. The spreadsheet presented herein utilizes different methods that use basic soil properties, such as grain size distribution and Atterberg limits, to calculate the input parameters for van Genuchten and Fredlund and Xing equations. These parameters are required by numerical models, such as SEEP/W, to perform transient seepage analysis. The spreadsheet allows copying the generated curve data points as well as an input into …

Effects Of System Reliability And Time Pressure On Autonomous Unmanned Aerial Vehicle Operator Performance And Mental Workload, Dahai Liu, Rania Ghatas, Christina Frederick-Recascino, Dennis Vincenzi Ph.D.

International Journal of Aviation, Aeronautics, and Aerospace

Unmanned Aerial Vehicles (UAVs) are in the midst of aviation’s next generation. UAVs are being utilized at an increasing rate by military and security operations and are becoming widely popular in usage for activities such as search and rescue and weather research to homeland security and border patrol. In order for a safer integration of UAV’s within the National Airspace System (NAS), many research questions need to be addressed. This study examined the effects of system reliability and time pressure on UAV operator performance and mental workload. Twenty-four undergraduate and graduate students, male and female, from Embry-Riddle Aeronautical University participated …

An Evaluation Of The Relationships Between Collegiate Aviation Safety Management System Initiative, Self-Efficacy, Transformational Safety Leadership And Safety Behavior Mediated By Safety Motivation, Daniel Kwasi Adjekum

International Journal of Aviation, Aeronautics, and Aerospace

The study conceptualized Safety Management System (SMS) initiative, self-efficacy, and transformational safety leadership as constructs that relates to safety behavior (measured by safety compliance and safety participation) when mediated by safety motivation using a quantitative approach. Structural equation modeling techniques was used to derive a final measurement model that fit the empirical data and was used to test the study hypotheses. Utilizing a sample of 282 collegiate flight students and instructors from a large public university in the US, a 46-item survey was used to measure respondent’s perceptions on the study variables. The results indicate that perceptions of SMS policy …

System And Method For Robust Nonlinear Regulation Control Of Unmanned Aerial Vehicles Synthetic Jet Actuators, Vladimir Golubev, William Mackunis

Publications

An unmanned aerial vehicle (UAV) is provided with a plurality of synthetic jet actuators and a nonlinear robust controller. The controller compensates for uncertainty in a mathematic model that describes the function of the synthetic jet actuators. Compensation is provided by the use of constant feedforward best guess estimates that eliminate the need for more highly computationally burdensome approaches such as the use of time-varying adaptive parameter estimation algorithms.

System And Method For Robust Nonlinear Regulation Control Of Unmanned Aerial Vehicles Synthetic Jet Actuators, Vladimir V. Golubev, William Mackunis

Publications

An unmanned aerial vehicle (UAV) is provided with a plurality of synthetic jet actuators and a nonlinear robust controller. The controller compensates for uncertainty in a mathematic model that describes the function of the syn­thetic jet actuators. Compensation is provided by the use of constant feedforward best guess estimates that eliminate the need for more highly computationally burdensome approaches such as the use of time-varying adaptive param­eter estimation algorithms.