Characteristics Of Rotating Detonation Engines For Propulsion And Power Generation,
2022
University of Central Florida
Characteristics Of Rotating Detonation Engines For Propulsion And Power Generation, Robert Burke
Electronic Theses and Dissertations, 2020-2023
Conventional engines are limited by the efficiency of their combustion mode. Compared to present constant pressure deflagration-based engines, detonation-based systems can realize a higher thermodynamic cycle efficiency, making them an attractive candidate for next generation propulsion systems that will take humanity to hypersonic speeds and even to Mars. For all its performance gains, detonation engines are still far off from implementation. One system, the rotating detonation engine (RDE) is promising as a detonation-based engine concept for its stability, simplicity, and versatility. For these reasons, RDEs have been the subject of studies internationally in efforts to understand their operation and integration …
The Effects Of Supersonic Reacting Flow Over A Wedge,
2022
University of Central Florida
The Effects Of Supersonic Reacting Flow Over A Wedge, Taylor R. Brown
Honors Undergraduate Theses
There is a growing need for a fundamental understanding of how detonations are formed and sustained as propulsion technology advances toward the use of detonation-based engines. The deflagration-to-detonation transition (DDT) phenomenon is studied to better understand both the fundamentals of detonation physics and the conditions surrounding how detonations are formed and sustained. This research aims to study the effects of a wedge on DDT and detonation formation. A hydrogen-air mixture is pumped into a chamber and ignited by a spark plug. Turbulence-driven flame acceleration is induced by turbulators in the chamber through which the flame propagates. The flame then flows …
Thrust Augmentation Of Rotating Detonation Rocket Engines,
2022
University of Central Florida
Thrust Augmentation Of Rotating Detonation Rocket Engines, Alexander G. Rodriguez
Honors Undergraduate Theses
This thesis aims to perform a detailed analysis on a 5th Order Polynomial Nozzle, verifying its effectiveness in improving the thrust performance of a Rotating Detonation Rocket Engine. Rotating detonation engines are a promising engine type that uses detonations as a means of combustion rather than traditional conflagration. Through this method, these engines can produce significant amounts of energy while burning less fuel in the process. However, exhaust flow instabilities and swirl limit the engine's potential for use as a means of propulsion. The 5th Order Polynomial Nozzle was previously demonstrated to reduce and control this swirl; however, analysis was …
Vibrations Of Rotationally Periodic Structures: A Metric For Mistuning Characterization And Vibration Localization,
2022
University of Central Florida
Vibrations Of Rotationally Periodic Structures: A Metric For Mistuning Characterization And Vibration Localization, Andres Rodriguez
Electronic Theses and Dissertations, 2020-2023
Blisk components are an integral part of jet engines and power generation systems. Composed of a single monolithic structure, integral blisks combine the blade-and-disk portion of primary components such as the fan, compressor stage, or turbine stage. This design modification increases the aerodynamic performance while decreasing the cost and eliminating time of assembly. However, these benefits come with the loss of blade-disk connection interfaces, which greatly reduces the structure's damping and its ability to attenuate unwanted structural vibrations. Blisk dynamics are impacted by mistuning, which is a disruption of the periodic symmetry of otherwise identical bladed sections. This disruption degrades …
Generic Behavior Framework Of Sx And Ds Nickel-Base Superalloys With Applications To Constitutive And Life Prediction Modeling,
2022
University of Central Florida
Generic Behavior Framework Of Sx And Ds Nickel-Base Superalloys With Applications To Constitutive And Life Prediction Modeling, Firat Irmak
Electronic Theses and Dissertations, 2020-2023
Selection of materials to be used for components experiencing extreme conditions is a critical process in the design phase. Nickel-base superalloys have been frequently used for hot gas path components in the turbomachinery industry. These components are required to withstand both fatigue and creep at extreme temperatures during their service time. In general, the extreme temperature materials mostly embody polycrystalline, directionally solidified, and single crystal superalloys. It is essential for design engineers to predict accurate damage behavior and lifespan for these components to prevent catastrophic failures. This dissertation presents a new framework to represent mechanical behavior of Nickel-base superalloys under …
The State Of The Art Of Information Integration In Space Applications,
2022
Old Dominion University
The State Of The Art Of Information Integration In Space Applications, Zhuming Bi, K. L. Yung, Andrew W.H. Ip., Yuk Ming Tang, Chris W.J. Zhang, Li Da Xu
Information Technology & Decision Sciences Faculty Publications
This paper aims to present a comprehensive survey on information integration (II) in space informatics. With an ever-increasing scale and dynamics of complex space systems, II has become essential in dealing with the complexity, changes, dynamics, and uncertainties of space systems. The applications of space II (SII) require addressing some distinctive functional requirements (FRs) of heterogeneity, networking, communication, security, latency, and resilience; while limited works are available to examine recent advances of SII thoroughly. This survey helps to gain the understanding of the state of the art of SII in sense that (1) technical drivers for SII are discussed and …
Drone Cage Design And Implementation To Enable Small Drone Architecture Testing,
2022
Embry-Riddle Aeronautical University
Drone Cage Design And Implementation To Enable Small Drone Architecture Testing, Marco Fagetti, Emily M. Suh
Undergraduate Student Works
Geometric mechanics is a dynamical formalism that allows for simultaneous treatment of rotational and translational motion without the drawbacks of attitude parameterization sets. While geometric mechanics is well suited to deal with full six degree-of-freedom motion or significant position-attitude coupling, this formalism has yet to be extensively applied to hardware systems. The broader research goals of this work aim to prove the practical viability of this theoretical framework by applying it to a class of Crazyflie drones, which are frequently used to assess Guidance, Navigation, and Control schemes. To efficiently achieve these goals, a reliable, collapsible drone cage is required …
Evaluation Of Onboard Detect-And-Avoid System For Suas Bvlos Operations,
2022
Oklahoma State University - Main Campus
Evaluation Of Onboard Detect-And-Avoid System For Suas Bvlos Operations, Jon M. Loffi, Samuel M. Vance, Jamey Jacob, Luke Spaulding, Jared C. Dunlap
International Journal of Aviation, Aeronautics, and Aerospace
No abstract provided.
Effect Of The Extended Rigid Flapping Trailing Edge Fringe On An S833 Airfoil,
2022
Wright State University
Effect Of The Extended Rigid Flapping Trailing Edge Fringe On An S833 Airfoil, Hongtao Yu, Zifeng Yang
Mechanical and Materials Engineering Faculty Publications
A 2D numerical simulation was conducted to investigate the effect of an extended rigid trailing edge fringe with a flapping motion on the S833 airfoil and its wake flow field, as an analogy of an owl’s wing. This study aims to characterize the influence of the extended flapping fringe on the aerodynamic performance and the wake flow characteristics downstream of the airfoil. The length (Le) and flapping frequencies (fe) of the fringe are the key parameters that dominate the impact on the airfoil and the flow field, given that the oscillation angular amplitude is fixed at 5◦. The simulation results …
Influence Of Nonlinear Multiaxial Matrix Viscoelasticity On Piezoresistivity Of Carbon Nanotube Polymer Composites,
2022
University of Central Florida
Influence Of Nonlinear Multiaxial Matrix Viscoelasticity On Piezoresistivity Of Carbon Nanotube Polymer Composites, Wolfgang Klimm
Electronic Theses and Dissertations, 2020-2023
Nanocomposites are prominent candidates to extend the capabilities in areas of established fiber reinforced composites. Carbon nanotubes (CNT) with their outstanding mechanical, electrical, and thermal properties are of particular interest. Especially polymers profit from the addition of CNTs, and can be rendered significantly stiffer, stronger, and even electrically conductive. The resulting electrical conductance is deformation-sensitive, known as piezoresistivity, and is utilized in strain sensing applications. However, the polymer matrix introduces time- and temperature-dependency into the mechanical behavior, known as viscoelasticity, and thus affects the relationship between deformation and electrical conductivity over time. Although piezoresistivity and polymer viscoelasticity have been studied …
Sensitivity Of Combustion Liner Contour To Sand Ingestion Clogging,
2022
University of Central Florida
Sensitivity Of Combustion Liner Contour To Sand Ingestion Clogging, Nelson Padilla
Electronic Theses and Dissertations, 2020-2023
This currently presented work is an evaluation of the characteristics of different cooling hole geometries to particulate ingestion clogging. Experimentation was conducted using a premixed bluff body flame combustor facility to generate high temperature combustor flow conditions. Sand ingestion along the cooling path of the combustion liner was reproduced using an air-assisted seeder providing consistent sand ingestion. Mass flow rate of cooling air was controlled using a sonic orifice downstream of a pressure regulator so that the mass flow rate of the air and sand mixture is independent of the clogging state. Pressure data upstream of a small section of …
Design And Mechanical Characterization Of Functionally Graded Sandwich Beams Fabricated Via Additive Manufacturing,
2022
University of Central Florida
Design And Mechanical Characterization Of Functionally Graded Sandwich Beams Fabricated Via Additive Manufacturing, Timothy Grondin
Electronic Theses and Dissertations, 2020-2023
Lightweight aerospace structures have been sought after since humans took flight in 1903, making major strides in NASA's pursuit of the moon with the development of sandwich panel composites. Sandwich structures typically consist of two stiff phases (i.e., face sheets) separated by a lightweight phase (i.e., core), which are stacked together through adhesive layers. Such a structural arrangement provides a high stiffness-to-weight ratio and is often used in applications where weight saving is critical. Functionally Graded Materials (FGMs), refer to multifunctional materials, which contain a spatial variation of composition and/or microstructure for the specific purpose of altering thermal and structural …
On Liquid Rotating Detonation Rocket Engines Characterization And Performance,
2022
University of Central Florida
On Liquid Rotating Detonation Rocket Engines Characterization And Performance, Vidhan Malik
Electronic Theses and Dissertations, 2020-2023
The current research investigates a next-generation method of combustion called detonations for propulsive applications which has support from the Combustion Services Branch at the Air Force Research Laboratory (AFRL) of the Rocket Propulsion Division. The overall initiative seeks to explore the viability of detonation-based systems to augment or replace current rocket propulsion methods in the coming five years. The present work progresses this vision by providing proof of a liquid RP-2 based Rotating Detonation Rocket Engine (RDRE) as well as the fundamentals associated with the physics involved to further the understanding of the phenomenon and its potential uses. Phase one …
A Unified Tool For Adaptive Collocation Techniques Applied To Solving Optimal Control Problems,
2022
University of Central Florida
A Unified Tool For Adaptive Collocation Techniques Applied To Solving Optimal Control Problems, Bethany Kelly
Electronic Theses and Dissertations, 2020-2023
In this work, a user-friendly MATLAB tool is introduced to solve nonlinear optimal control problems by applying collocation techniques using Coupled Radial Basis Functions (CRBFs). CRBFs are a new class of Radial Basis Functions combined with a conical spline r^5, which provides the advantage of insensitivity to the shape parameter while maintaining accuracy and robustness. To solve optimal control problems, software tools are often employed to implement numerical methods and apply advanced techniques to solving differential equations. Although several commercial software tools exist for solving optimal control problems, such as ICLOCS2, GPOPS, and DIDO, there are no options available that …
The Breakup Of Rp-2 Liquid Fuel Droplets In A Detonation Field,
2022
University of Central Florida
The Breakup Of Rp-2 Liquid Fuel Droplets In A Detonation Field, Daniel Dyson
Electronic Theses and Dissertations, 2020-2023
Experimentally obtained droplet breakup patterns are presented for RP-2 liquid fuel droplets in the environment behind a detonation wave. To the best of our knowledge, this data is the first of its kind to examine the fundamental interactions between detonation waves and an individual fuel droplet. The experiments presented here are expected to support the ongoing effort of creating accurate models of droplet breakup in a variety of environments, which in turn will lead to enhanced predictions of rotating detonation engine performance, improved safety considerations for facilities operating in hazardous conditions, and new knowledge in energetics, hypersonics, and explosion dynamics …
The Utilization And Loss Of Available Energy In Aerospace Systems,
2022
Missouri University of Science and Technology
The Utilization And Loss Of Available Energy In Aerospace Systems, Mohammad Abbas
Doctoral Dissertations
“Theoretical principles and analytical methodology for the control volume-based energy availability methodology for aerospace vehicles are developed; applications are made to jet-propelled and rocket-propelled vehicles as well as to stand-alone engine systems. Energy availability utilization characteristics of a modeled turbojet engine are studied across a wide range of operating conditions of throttle setting, flight altitude, and flight Mach number. The method is also extended to consider jet-powered vehicles. Fundamental principles regarding entropy generation and energy availability are developed, including directly linking entropy generation and maximum range and endurance of a powered aircraft. Theory and application of the energy utilization methodology …
Theoretical And Experimental Application Of Neural Networks In Spaceflight Control Systems,
2022
Missouri University of Science and Technology
Theoretical And Experimental Application Of Neural Networks In Spaceflight Control Systems, Pavel Galchenko
Doctoral Dissertations
“Spaceflight systems can enable advanced mission concepts that can help expand our understanding of the universe. To achieve the objectives of these missions, spaceflight systems typically leverage guidance and control systems to maintain some desired path and/or orientation of their scientific instrumentation. A deep understanding of the natural dynamics of the environment in which these spaceflight systems operate is required to design control systems capable of achieving the desired scientific objectives. However, mitigating strategies are critically important when these dynamics are unknown or poorly understood and/or modelled. This research introduces two neural network methodologies to control the translation and rotation …
Integrating Experimental Parameter Space For Granular Flow Within Polygon Tumblers,
2022
Northern Illinois University
Integrating Experimental Parameter Space For Granular Flow Within Polygon Tumblers, Michaela Mcmahon
Graduate Research Theses & Dissertations
Granular flows are complex phenomena bridging both fluid and solid mechanics and observed frequently in the natural world. The transitional dynamics of acceleration from solid body motion to rapid flow can affect many aspects including volume flow rates and mixing behaviors. In order to study the combination of both variables together within polygon-shaped tumblers, control systems are necessary with a corresponding user interface. This thesis reports an interface for changing variable inputs to the system. Predictions of rotation rates with corresponding interfaces with hardware connections are described. Results of image analysis verify output performance that incorporates the following variable changes: …
Experimental Analysis Of Flowing Layer Characteristics In Equilateral Triangular Tumblers For Quasi-2d Macro-Particle Flow,
2022
Northern Illinois University
Experimental Analysis Of Flowing Layer Characteristics In Equilateral Triangular Tumblers For Quasi-2d Macro-Particle Flow, Jason Quinn Ostenburg
Graduate Research Theses & Dissertations
Rotating tumblers are used in a wide variety of industrial applications from mixing anddeburring to flow regulation and storage. Almost all model tumblers previously analyzed, both theoretically and experimentally, had circular cross sections that produced consistent flowing layer dimensions and steady state flow. In contrast, tumblers with triangular cross sections produced unsteady flow as a direct result of the dynamic dimensions of the flowing surface. Although unsteady, the flow produced in triangular tumblers is periodic every 120◦ of rotation after an initial mixing period. The mechanisms by which the flow characteristics vary as a triangular tumbler rotates and the number …
Design, Development, And Testing Of Near-Optimal Satellite Attitude Control Strategies,
2022
South Dakota State University
Design, Development, And Testing Of Near-Optimal Satellite Attitude Control Strategies, Giovanni Lavezzi
Electronic Theses and Dissertations
Advances in space technology and interest toward remote sensing mission have grown in the recent years, requiring the attitude control subsystems of observation satellites to increase their performances in terms of pointing accuracy and on-board implementability. Moreover, an increased interest in small satellite missions and the recent technological developments related to the CubeSats standard have drastically reduced the cost of producing and flying a satellite mission. In this context, the proposed research aims to improve the state of the art for satellite attitude control methodologies by proposing a near-optimal attitude control strategy, simulated in a high-fidelity environment. Two strategies are …
