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Articles 4681 - 4710 of 11196

Full-Text Articles in Aerospace Engineering

Free Response And Trim Force Requirements For Aircraft Configuration Changes, Marvin Toepfer Dec 2018

Free Response And Trim Force Requirements For Aircraft Configuration Changes, Marvin Toepfer

Theses and Dissertations

As an FAA Commercial Pilot and Flight Instructor, one comes in contact with many different types of experiences and abnormal situations. A widely known cause of fatal accidents in the general aviation industry, and also currently listed on the National Transportation Safety Board Most Wanted List, is the loss of control in the traffic pattern [1]. For many years now, different departments of the FAA and Department of Transportation, such as the FAA Small Airplane Directorate, have been trying to mitigate the risks and causes associated with the loss of control in the traffic pattern. Due to technological advancements and …


Quantitative Measurement Techniques For Vibration And Buffet, Edward Thomas Meyer Dec 2018

Quantitative Measurement Techniques For Vibration And Buffet, Edward Thomas Meyer

Theses and Dissertations

This paper outlines a proposed parameter for measurement of vibration and buffet in vehicles. It is intended to be used where applicable in lieu of raw accelerometer data or qualitative comments to measure ride quality, quantify vibration levels, and aid in certification matters. In flight vehicle applications which employ fly-by wire flight control systems with closed loop and variable gain control laws, the phenomenon of buffet in its various forms is becoming somewhat specious as an aircrew cue in relation to the stability and control of flight vehicles. In these applications, stability and control throughout the operating envelope is designed …


Aerodynamic Model Of The Piper Warrior Ii Based On Flight Test Data, Nicholas Casciola Dec 2018

Aerodynamic Model Of The Piper Warrior Ii Based On Flight Test Data, Nicholas Casciola

Theses and Dissertations

Aerodynamic modeling is an important part of aircraft design and of aircraft testing. Generally, this is done through CFD models and Wind Tunnel tests prior to the aircrafts first flight but building the models using flight test data is also very important. It is used to verify theoretical models generated from the computer and wind tunnel tests. They are also useful for building simulators, particularly those in modeling and analyzing airport traffic patterns. These tests used a Piper Pa-28-161 Warrior II owned by the Florida Tech Flight Test Engineering program. It has a 160hp Lycoming engine. The test pilot was …


Development Of Adaptable Human-Machine Interface For Teleoperation Over Time Delay, May Nyein Chan Dec 2018

Development Of Adaptable Human-Machine Interface For Teleoperation Over Time Delay, May Nyein Chan

Theses and Dissertations

The Adaptable Human-Machine Interface (AHMI) was developed for the Orbital Robotic Interaction, On-orbit servicing, and Navigation (ORION) Laboratory of the Florida Institute of Technology. The primary project objective was to develop and test a predictive display for mitigating the effects of time delay in teleoperation of space robots and Unmanned Aerial Vehicles (UAV) using quadcopters as a test case. Regardless of the increasing popularity of various autonomous systems, research and development of teleoperating system should not be neglected since it is often utilized as a back-up in most autonomous systems especially in systems for human spaceflight and UAV operations in …


Cubesat Docking And Resource Sharing Mechanism, Shingo Kunito Dec 2018

Cubesat Docking And Resource Sharing Mechanism, Shingo Kunito

Theses and Dissertations

This thesis addresses the design concept of a CubeSat docking and resource sharing mechanism that allows to transfer propellant that is pressurized gas, data, and power. In docking and capture design, the interface is equipped with two air cylinders that are rated up to 20.68 MPa internal pressure generating the ideal force of 1218.4 N each. With the designed air cylinder and mounted configuration, the maximum capture distance between the target and the chaser CubeSat is 40.30 mm. Since air cylinder and body frame are designed specifically for this interface, structural analysis was conducted in ANSYS where results show a …


Experimental And Computational Analysis Of The Interaction Of Carbon And Silicon Ablation Products In Expanding Hypersonic Flows, Brian E. Donegan Dec 2018

Experimental And Computational Analysis Of The Interaction Of Carbon And Silicon Ablation Products In Expanding Hypersonic Flows, Brian E. Donegan

Theses and Dissertations

Thermal protection is required for vehicles entering planetary atmospheres to protect against the severe heating loads experienced. Characterization of candidate materials is often done utilizing plasma or arc-jet facilities, which provide steady-state testing of the thermal environments experienced during hypersonic flight, but do not correctly simulate hypersonic flowfields. Conversely, impulse facilities can reproduce flight velocities and enthalpies but have extremely short test times, prohibiting testing of thermal response. Modeling ablation and heating rates, particularly in the wake region, remains a significant challenge due to the complexity of the flowfield. To better understand this complex phenomenon and provide data to validate …


Controller Evolution And Divergence: A Software Perspective, Balaji Balasubramaniam Nov 2018

Controller Evolution And Divergence: A Software Perspective, Balaji Balasubramaniam

School of Computing: Dissertations, Theses, and Student Research

Successful controllers evolve as they are refined, extended, and adapted to new systems and contexts. This evolution occurs in the controller design and also in its software implementation. Model-based design and controller synthesis can help to synchronize this evolution of design and software, but such synchronization is rarely complete as software tends to also evolve in response to elements rarely present in a control model, leading to mismatches between the control design and the software.

In this thesis, we perform a first-of-its-kind study on the evolution of two popular open-source safety-critical autopilot control software -- ArduPilot, and Paparazzi, to better …


Dynamic Optimization Of High-Altitude Solar Aircraft Trajectories Under Station-Keeping Constraints, Ronald Abraham Martin, Nathaniel Gates, Andrew Ning, John Hedengren Nov 2018

Dynamic Optimization Of High-Altitude Solar Aircraft Trajectories Under Station-Keeping Constraints, Ronald Abraham Martin, Nathaniel Gates, Andrew Ning, John Hedengren

Faculty Publications

This paper demonstrates the use of nonlinear dynamic optimization to calculate energy optimal trajectories for a high-altitude, solar-powered Unmanned Aerial Vehicle (UAV). The objective is to maximize the total energy in the system while staying within a 3 km mission radius and meeting other system constraints. Solar energy capture is modeled using the vehicle orientation and solar position, and energy is stored both in batteries and in potential energy through elevation gain. Energy capture is maximized by optimally adjusting the angle of the aircraft surface relative to the sun. The UAV flight and energy system dynamics are optimized over a …


Assessing The Limitations Of Effective Number Of Samples For Finding The Uncertainty Of The Mean Of Correlated Data, Barton L. Smith, Douglas R. Neal, Mark Feero, Geordie Richards Nov 2018

Assessing The Limitations Of Effective Number Of Samples For Finding The Uncertainty Of The Mean Of Correlated Data, Barton L. Smith, Douglas R. Neal, Mark Feero, Geordie Richards

Mechanical and Aerospace Engineering Faculty Publications

The efficacy of recent and classical theories on the uncertainty of the mean of correlated data have been investigated. A variety of very large data sets make it possible to show that, under circumstances that are often too expensive to achieve, the integral time scale can be used to determine the effective number of independent samples, and therefore the uncertainty of the mean. To do so, the data set must be sufficiently large that it may be divided into many records, each of which is many integral time scales long. In this circumstance, all lags of the autocorrelation should be …


Toward Building Resilient, Sustainable, And Smart Infrastructure In The 21st Century, Aly Mousaad Aly Nov 2018

Toward Building Resilient, Sustainable, And Smart Infrastructure In The 21st Century, Aly Mousaad Aly

Faculty Publications

In recent years, as a result of significant climate change, stringent windstorms are becoming more frequent than before. Given the threat that windstorms bring to people and property, wind/structural engineering research is imperative to improve the resilience of existing and new infrastructure, for community safety and assets protection. The Windstorm Impact, Science and Engineering (WISE) research program at Louisiana State University (LSU) focuses on creating new knowledge applicable to the mitigation of existing and new infrastructure, to survive and perform optimally under natural hazards. To achieve our research goals, we address two imperious challenges: (i) characterization of realistic wind forces …


Optimal Attitude Control Of A Two-Cubesat Virtual Telescope In A Highly Elliptical Orbit, Reza Pirayeshshirazinezhad Nov 2018

Optimal Attitude Control Of A Two-Cubesat Virtual Telescope In A Highly Elliptical Orbit, Reza Pirayeshshirazinezhad

Shared Knowledge Conference

This paper investigates a novel approach for attitude control of 2 satellites acting as a virtual telescope. The Virtual Telescope for X-ray Observations (VTXO) is a mission exploiting 2 6U-CubeSats operating in a precision formation. The goal of the VTXO project is to develop a space-based, X-ray imaging telescope with high angular resolution precision. In this scheme, one CubeSat carries a diffractive lens and the other one carries an imaging device to support a focal length of 100 m. In this mission, the attitude control algorithms are required to keep the two spacecraft in alignment with the Crab Nebula observations. …


Pulsed Fiber Optics Lasers As Highly Sensitive Sensors, Hanieh Afkhamiardakani Nov 2018

Pulsed Fiber Optics Lasers As Highly Sensitive Sensors, Hanieh Afkhamiardakani

Shared Knowledge Conference

An interferometer or resonator is a device in which optical beams of specific frequencies circulate with minimal losses. These losses are completely compensated by the gain inside a laser resonator. A small perturbation introduced inside the laser can affect its frequency, which in turns becomes a metric of that perturbation. The perturbation is usually caused by an electric or magnetic field, rotation, acceleration, nonlinear index of refraction etc. Tiny changes of optical frequency are monitored by superimposing the laser field and a reference field (from the same laser) on a detector. This technique requires creating a laser in which two …


Physical Properties Of Engineered Nanocomposites For Defense Applications, Alex Henson, Sanju Gupta Nov 2018

Physical Properties Of Engineered Nanocomposites For Defense Applications, Alex Henson, Sanju Gupta

Posters-at-the-Capitol

Polymer nanocomposites are significant for modern and future technologies (aerospace, defense, water purification etc.) due to their tailored properties, lightweight and low cost. However, ‘forward’ engineered polymer (host matrix) composites with smaller size nanoparticles (guest) providing desired properties targeting specific applications remains a challenging task as they depend largely on nanoparticles size, shape and loading (volume fraction). This study develops polymer nanocomposites impregnated with ‘organic-inorganic’ silsesquioxane nanoparticles and graphene nanoribbons, and investigates microscopic structure and dynamics of interfacial layer to predict macroscale properties. The nanocomposites consist of poly(2-vinylpyridine) (P2VP) polymer (segment ~5nm) with spherical silsesquioxane nanoparticles (diameter ~2-5nm) and planar …


Control Of Uncertain Dynamical Systems With Spatial And Temporal Constraints, Ehsan Arabi Nov 2018

Control Of Uncertain Dynamical Systems With Spatial And Temporal Constraints, Ehsan Arabi

USF Tampa Graduate Theses and Dissertations

The overarching objective of this dissertation is the development of feedback control frameworks for uncertain dynamical systems that are subject to spatial and/or temporal constraints. These spatiotemporal constraints usually arise from the physical and/or performance characteristics associated with a considered dynamical system in safety-critical applications, where synthesis and analysis of feedback control laws are not trivial. Specifically, the proposed control architectures in this dissertation mainly contribute to the model reference adaptive control and finite-time control literature. In particular, unlike existing model reference adaptive control approaches that are not capable of enforcing user-defined performance guarantees without an ad-hoc tuning process, the …


Enhancing Your Intelligence Agency Information Resource Iq: Pt. 4: National Geospatial Intelligence Agency (Ngia), National Intelligence University (Niu), And National Reconnaissance Office (Nro), Bert Chapman Nov 2018

Enhancing Your Intelligence Agency Information Resource Iq: Pt. 4: National Geospatial Intelligence Agency (Ngia), National Intelligence University (Niu), And National Reconnaissance Office (Nro), Bert Chapman

Libraries Faculty and Staff Presentations

Webinar presentation on publicly accessible information resources produced by the U.S. National Geospatial Intelligence Agency (NGIA), National Intelligence University (NIU), and National Reconnaissance Office. Places significant emphasis on missions of these agencies, their historical accomplishments, coverage of their educational activity, and information on the technologies they have used and are currently using to fulfill their institutional objectives.


Nasa Maa (Murep Aerospace Academy) Stem Project At York College: Ensuring Future Stem Pipeline, Nazrul I. Khandaker, Shuayb Siddique, Matthew Khargie, Brandon Dhanraj, Zachary A. Sanichar, Mildred M. Selby, Chabenauth Ramnauth, Theresa Deepan, Yougeeta Singh, Krishna Mahabir, Sashi Singh, Omadevi Singh Nov 2018

Nasa Maa (Murep Aerospace Academy) Stem Project At York College: Ensuring Future Stem Pipeline, Nazrul I. Khandaker, Shuayb Siddique, Matthew Khargie, Brandon Dhanraj, Zachary A. Sanichar, Mildred M. Selby, Chabenauth Ramnauth, Theresa Deepan, Yougeeta Singh, Krishna Mahabir, Sashi Singh, Omadevi Singh

Publications and Research

Our ongoing K1-12 NASA-supported STEM activities has served over 5000 children since 2015, largely from groups that are undeserved and underrepresented in the sciences. These STEM activities have been successfully delivered for several years and include earth science, meteorite geology, rocketry, aerodynamics, star gazing, EV3 Mindstorm robotics, basic coding exercises, wind tunnel, 3D-printing, etc., conducted largely through our present MAA (MUREP Aerospace Academy) Project. Corporate funding from the Con Edison and National Grid ensures additional STEM dissemination to the students during the summer operation. Significant positive component of the MAA program is the availability and willingness of the former student …


Air Temperatures Tutorial, Nihad E. Daidzic Nov 2018

Air Temperatures Tutorial, Nihad E. Daidzic

Aviation Department Publications

No abstract provided.


Prediction Of Thermal Conductance At Liquid-Gas Interfaces Using Molecular Dynamics Simulations, James Gonzalez, Josue Ortega, Zhi Liang Nov 2018

Prediction Of Thermal Conductance At Liquid-Gas Interfaces Using Molecular Dynamics Simulations, James Gonzalez, Josue Ortega, Zhi Liang

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Using Molecular Dynamics (MD) Simulations and Theoretical Calculations, We Study Heat Transfer Across Liquid-Gas Interfaces within a Planar Heat Pipe. to Determine the Thermal Conductance (Kapitza Conductance), GK, at the Interface, Two Heat Transfer Mechanisms, Namely, Conduction and Evaporation/condensation Are Considered. in the Case of Interfacial Heat Conduction, Gas Molecules, Particularly Non-Condensable Gas Molecules, Exchange Heat with Liquid Surfaces through Gas-Liquid Collisions, and the Theoretical Expression for GK is Derived from the Kinetic Theory of Gases. for Interfacial Heat Transfer by Evaporation or Condensation, the Theoretical Expression for GK is Derived from the Schrage Relationships. to Assess the Accuracies of …


Development, Training, Education, And Implementation Of Low-Cost Sensing Technologies For Bridge Structural Health Monitoring (Shm), Fernando Moreu, Chris Lippitt, Dilendra Maharjan, Marlon Aguero, Roya Nasimi Nov 2018

Development, Training, Education, And Implementation Of Low-Cost Sensing Technologies For Bridge Structural Health Monitoring (Shm), Fernando Moreu, Chris Lippitt, Dilendra Maharjan, Marlon Aguero, Roya Nasimi

Publications

Transportation infrastructure needs continuous monitoring. However, traditional inspections cost money and are conducted visually. New technologies for bridge monitoring are expensive and complex. This project involved developing cost-effective sensor technologies that can be applied towards the maintenance of railroad bridges by recording reference-free transverse displacement. More specifically, this project developed new applications of new technologies (Arduino, wireless smart sensors, drones, Hololens) and promoted workforce development with an emphasis on outreach of high-school students. This project was carried out in three main phases: (1) development and validation of technologies, (2) education and outreach to students, and (3) outreach to industry consisting …


Evaluation Of The 20 L Dust Explosibility Testing Chamber And Comparison To A Modified 38 L Vessel For Underground Coal, Robert Quentin Eades, Kyle A. Perry, Catherine E. Johnson, Jacob Miller Nov 2018

Evaluation Of The 20 L Dust Explosibility Testing Chamber And Comparison To A Modified 38 L Vessel For Underground Coal, Robert Quentin Eades, Kyle A. Perry, Catherine E. Johnson, Jacob Miller

Mining Engineering Faculty Research & Creative Works

The phenomenon of combustible dust explosions is present within many industries. Tests for explosibility of dust clouds per ASTM E1226 use a 20 L explosive chamber that places the combustible dust directly below the dispersion nozzle which generates a thorough mixture for testing purposes. However, in the underground coal mining industry, there are a number of geologic, mining, and regulatory factors that change the deposition scheme of combustible coal dust. This causes the atmosphere of a coal mine to have a variable rock dust-coal dust mixture at the time of ignition. To investigate the impact of this variable atmosphere, a …


Direct Adaptive Control For A Trajectory Tracking Uav, Nirmit Prabhakar Nov 2018

Direct Adaptive Control For A Trajectory Tracking Uav, Nirmit Prabhakar

Doctoral Dissertations and Master's Theses

This research focuses on the theoretical development and analysis of a direct adaptive control algorithm to enable a fixed-wing UAV to track reference trajectories while in the presence of persistent external disturbances. A typical application of this work is autonomous flight through urban environments, where reference trajectories would be provided by a path planning algorithm and the vehicle would be subjected to significant wind gust disturbances. Full 6-DOF nonlinear and linear UAV simulation models are developed and used to study the performance of the direct adaptive control system for various scenarios. A stability proof is developed to prove convergence of …


Variable Fidelity Studies In Wake Vortex Evolution, Safety, And Control, Petr Kazarin Nov 2018

Variable Fidelity Studies In Wake Vortex Evolution, Safety, And Control, Petr Kazarin

Doctoral Dissertations and Master's Theses

The purpose of this research is to develop a variable-fidelity approach for addressing the safety of unmanned aerial system (UAS) operations in the national aerospace system (NAS). This task is implemented on the basis of safety investigation toolkit for analysis and reporting wake vortex safety system (SITAR WVSS) code, which is a dynamic low-fidelity model addressing generation, evolution, and interaction of the leader-aircraft wake vortex with the follower-aircraft lifting surfaces.

The first part of the dissertation deals with the generation, evolution, and interaction of the wake vortices produced by an aircraft. In particular, it presents the results of the vortex …


A Numerical And Experimental Evaluation Of The Turbulent Heat Flux In A Heated Jet In Crossflow, Michael R. Borghi Jr. Nov 2018

A Numerical And Experimental Evaluation Of The Turbulent Heat Flux In A Heated Jet In Crossflow, Michael R. Borghi Jr.

Doctoral Dissertations and Master's Theses

The injection of fully-developed turbulent heated air from a tube into a cooler turbulent duct flow is examined, as an analogy to film cooled turbine blades. Scale Resolving Simulations (SRS) are used to examine the flow numerically. A Detached Eddy Simulation (DES) methodology is examined but found to be ineffective at correctly capturing the physics of the flow. A Large Eddy Simulation (LES) numerical model is developed and applied in which tube and duct turbulence inflow effects are emulated using a divergence-free synthetic eddy method (SEM). The LES sensitivity to the synthetic inflow turbulence is examined with a series of …


Topology Optimization Using Load Path And Homogenization, Kaveh Gharibi Nov 2018

Topology Optimization Using Load Path And Homogenization, Kaveh Gharibi

Doctoral Dissertations and Master's Theses

In this work, the connection between topology optimization and load transfer has been established. New methods for determining load paths in two dimensional structures, plates and shells are introduced. In the two-dimensional space, there are two load paths with their total derivative equal to the transferred load, their partial derivatives related to stress tensor, and satisfying equilibrium. In the presence of a body load the stress tensor can be decomposed into solenoidal and irrotational fields using Gurtin or Helmholtz decomposition. The load path is calculated using the solenoidal field. A novel method for topology optimization using load paths and total …


Comparing Specific Excess Power Of General Aviation Aircraft, Yohan Forbes Auguste Nov 2018

Comparing Specific Excess Power Of General Aviation Aircraft, Yohan Forbes Auguste

Theses and Dissertations

The high number of Loss of Control and Controlled Flight into Terrain Accidents in General Aviation (GA) suggests that there is a lack of understanding and recognition of low energy states by pilots of GA aircraft. As a result there is a desire to implement an energy management system in GA aircraft to alert the pilot of low energy conditions and to give the required corrective action to get to a desired energy state. This requires an understanding of the performance capabilities of GA aircraft in terms of their ability to change their energy state. The ability to change the …


Mission Overview For A Cislunar Gamma-Ray Burst Detector, Chandler Ellis, Jared Fuchs Oct 2018

Mission Overview For A Cislunar Gamma-Ray Burst Detector, Chandler Ellis, Jared Fuchs

Von Braun Symposium Student Posters

No abstract provided.


L1 Month: Utilizing High Power Rocketry As A Training Tool For Student Organizations, Aaron Hunt, Oakley Copeland, Mckynzie Perry, Benjamin Thomas Oct 2018

L1 Month: Utilizing High Power Rocketry As A Training Tool For Student Organizations, Aaron Hunt, Oakley Copeland, Mckynzie Perry, Benjamin Thomas

Von Braun Symposium Student Posters

No abstract provided.


Anticoincidence Detector Performance Analysis, Christopher Helmerich, Erik Korzon Oct 2018

Anticoincidence Detector Performance Analysis, Christopher Helmerich, Erik Korzon

Von Braun Symposium Student Posters

No abstract provided.


How Spaceflight Affects The Detachment Of Zinc Whiskers, Kayla Capitan Oct 2018

How Spaceflight Affects The Detachment Of Zinc Whiskers, Kayla Capitan

Von Braun Symposium Student Posters

No abstract provided.


Analytical Modeling Of Heat Deposition In Propellant For Spacecraft Utilizing Nuclear Thermal Propulsion, Alexander Aueron Oct 2018

Analytical Modeling Of Heat Deposition In Propellant For Spacecraft Utilizing Nuclear Thermal Propulsion, Alexander Aueron

Von Braun Symposium Student Posters

No abstract provided.