A Study Of Microgravity On Fluid Transport Through Porous Structures In Microfluidic Devices,
2022
University of Central Florida
A Study Of Microgravity On Fluid Transport Through Porous Structures In Microfluidic Devices, Sylvain Le Henaff
Electronic Theses and Dissertations, 2020-2023
The objective of this study is to refine the understanding of micro-fluidics subject to micro-gravity in an attempt to support future space exploration efforts. A combination of experimental and numerical approaches were utilized to build a validated assessment approach. A quasi-pore geometry, inspired by CT scans of rat bones, was used in lieu of human bone structures. A quasi-1D assessment of the conservation of momentum was used to identify the dominant forces acting on the fluid at the operating length-scales. The dominant forces were surface tension, gravity, and shear stress. Experiments were conducted to visualize the flow moving through the …
Interactions Of Aerosol Droplets With Ventilated Airflows In The Context Of Airborne Pathogen Transmission,
2022
University of Central Florida
Interactions Of Aerosol Droplets With Ventilated Airflows In The Context Of Airborne Pathogen Transmission, Steven Schroeder
Electronic Theses and Dissertations, 2020-2023
This multidisciplinary study provides a comprehensive visualization of airborne aerosols and droplets coming into contact with a crossflow of moving air utilizing both experimental particle measuring methods and multiphase computational fluids dynamics (CFD). The aim of this research is to provide a Eulerian visualization of how ventilation can alter the position and density of an aerosol cloud, with the goal of applying this information to our understanding of social distancing ranges within outdoor settings and ventilated rooms. The results indicate that even minor perpendicular crossflows across the trajectory of an aerosol cloud can greatly reduce both the linear displacement and …
Shape Parameter & Nodal Distribution Insensitive Radial Basis Functions For Nonlinear Optimal Control Problems,
2022
University of Central Florida
Shape Parameter & Nodal Distribution Insensitive Radial Basis Functions For Nonlinear Optimal Control Problems, Ahmed Elsadek Ahmed Elshafee Seleit
Electronic Theses and Dissertations, 2020-2023
Computational optimal control relies mainly on pseudospectral methods. The use of Chebyshev and Legendre polynomials is ubiquitous in the literature. This family of methods has good accuracy characteristics but constraints the nodal distribution to a certain grid that is denser at the boundaries. In this work, a set of novel Coupled Radial Basis Functions (CRBFs) is introduced as an approximation means for the nonlinear optimal control problem. CRBFs are real-valued Radial Basis Functions (RBFs) augmented with a conical spline. They do not require a specific nodal distribution. A plethora of research articles were published on the optimization of the shape …
Precise Landing Of Vtol Uavs Using A Tether,
2022
West Virginia University
Precise Landing Of Vtol Uavs Using A Tether, Jeremy W. Rathjen
Graduate Theses, Dissertations, and Problem Reports (ETD)
Unmanned Aerial Vehicles (UAVs), also known as drones, are often considered the solution to complex robotics problems. The significant freedom to explore an environment is a major reason why UAVs are a popular choice for automated solutions. UAVs, however, have a very limited flight time due to the low capacity and weight ratio of current batteries. One way to extend the vehicles' flight time is to use a tether to provide power from external batteries, generators on the ground, or another vehicle. Attaching a tether to a vehicle may constrain its navigation but it may also create some opportunities for …
Aerodynamic Analysis Of Damage State Missiles Using Overset Meshing Techniques For Application To Computational Fluid Dynamics Simulation,
2022
West Virginia University
Aerodynamic Analysis Of Damage State Missiles Using Overset Meshing Techniques For Application To Computational Fluid Dynamics Simulation, Jonathan A. D'Alessio
Graduate Theses, Dissertations, and Problem Reports (ETD)
Significant research over the years has aimed to redefine the flight capabilities of aircraft after sustaining structural damage to critical components. Flight survivability and controllability are key areas of concern when designing fault-tolerant flight control systems to handle a wide range of potential scenarios. However, there is a lack of research on the impact of physically damaged missile systems. Missile counter-defense and intercept capabilities have become more advanced as the United States has focused heavily on these areas over the years. Damaged missiles due to a kinetic intercept capability present an opportunity for analysis of the post-damage implications on flight …
Probabilistic Space Weather Modeling And Forecasting For The Challenge Of Orbital Drag In Space Traffic Management,
2022
West Virginia University
Probabilistic Space Weather Modeling And Forecasting For The Challenge Of Orbital Drag In Space Traffic Management, Richard J. Licata Iii
Graduate Theses, Dissertations, and Problem Reports (ETD)
In the modern space age, private companies are crowding the already-congested low Earth orbit (LEO) regime with small satellite mega constellations. With over 25,000 objects larger than 10 cm already in LEO, this rapid expansion is forcing us towards the enterprise on Space Traffic Management (STM). STM is an operational effort that focuses on conjunction assessment and collision avoidance between objects. While the equations of motion for objects in orbit are well-known, there are many uncertain parameters that result in the uncertainty of an object's future position. The force that the atmosphere exerts on satellite - known as drag - …
Numerical Investigation On The Effect Of Spectral Radiative Heat Transfer Within An Ablative Material,
2021
University of Kentucky
Numerical Investigation On The Effect Of Spectral Radiative Heat Transfer Within An Ablative Material, Raghava S. C. Davuluri, Rui Fu, Kaveh A. Tagavi, Alexandre Martin
Mechanical Engineering Faculty Publications
The spectral radiative heat flux could impact the material response. In order to evaluate it, a coupling scheme between KATS - MR and P1 approximation model of radiation transfer equation (RTE) is constructed and used. A Band model is developed that divides the spectral domain into small bands of unequal widths. Two verification studies are conducted: one by comparing the simulation computed by the Band model with pure conduction results and the other by comparing with similar models of RTE. The comparative results from the verification studies indicate that the Band model is computationally efficient and can be used to …
Analysis Of Multiple Degree-Of-Freedom Oscillatory Aquatic Propulsion,
2021
Syracuse University
Analysis Of Multiple Degree-Of-Freedom Oscillatory Aquatic Propulsion, Seth Alan Brooks
Dissertations - ALL
Propulsive performance and flow field data were experimentally measured for a two degree-of-freedom fish platform. The fish platform was designed and constructed based on the yellowfin tuna (\textit{Thunnus albacares}) that is known to be both fast and efficient. This work extends the current understanding of oscillatory aquatic propulsion to a three-dimensional fish platform with full volume flow field data and propulsive performance. A parametric sweep of trailing-edge amplitude of the caudal fin ($A$), heave-to-pitch ratio ($h^*$), and phase offset between the two degrees-of-freedom ($\phi$) was used to explore a parameter space that encompasses and extends beyond the known biological domain. …
Direct Foam Writing In Microgravity,
2021
West Virginia University
Direct Foam Writing In Microgravity, Guy Jacob Cordonier, Cicely Sharafati, Spencer Mays, Lukas Thackery, Ellena Gemmen, Samuel Cyphert, Megan Brown, John Quinn Napolillo, Savannah Toney, Hunter Moore, John M. Kuhlman `, Konstantinos A. Sierros
Faculty & Staff Scholarship
Herein we report 2D printing in microgravity of aqueous-based foams containing metal oxide nanoparticles. Such hierarchical foams have potential space applications, for example for in situ habitat repair work, or for UV shielding. Foam line patterns of a TiO2-containing foam have been printed onto glass substrates via Direct Foam Writing (DFW) under microgravity conditions through a parabolic aircraft flight. Initial characterization of the foam properties (printed foam line width, bubble size, etc.) are presented. It has been found that gravity plays a significant role in the process of direct foam writing. The foam spread less over the substrate when deposited …
State-Of-The-Art Of Thermal Control Solutions To Establish A Modular, Multi-Orbit Capable Spacecraft Thermal Management System Design Methodology,
2021
Embry-Riddle Aeronautical University
State-Of-The-Art Of Thermal Control Solutions To Establish A Modular, Multi-Orbit Capable Spacecraft Thermal Management System Design Methodology, Robert C. Consolo Jr
Doctoral Dissertations and Master's Theses
Today, the exploration and exploitation of space continues to become a more common occurrence. All types of spacecraft (S/C) utilize various types of thermal management solutions to mitigate the effects of thermal loading from the unforgiving vacuum of space. Without an appropriately designed thermal system, components on-board the S/C can experience failure or malfunction due to fluctuations in temperatures either beyond the designed operational parameters or unstable oscillating temperatures. The purpose of this study is to perform a comprehensive review of technologies available today that are being used for thermal management onboard S/C in addition to investigating the means to …
Numerical Simulation Of A Cryogenic Spray,
2021
Embry-Riddle Aeronautical University
Numerical Simulation Of A Cryogenic Spray, Neel Kishorkumar Shah
Doctoral Dissertations and Master's Theses
Cryogenic sprays have many applications in modern engineering. Cooling of electronic equipment subject to high heat flows, surgical ablation of gastrointestinal mucosae or orbital maneuvering are a few examples of their versatility. However, the atomization of a cryogenic liquid is a complex process. During such an event, aerodynamic effects associated with secondary atomization are further affected by thermodynamic flashing. A better understanding of the characteristics of cryogenic sprays is then necessary to allow for improved design and optimization in applications. The overarching objective of this study is to document such characteristics. The numerical simulation was performed over cryogenic nitrogen spray …
In-Situ Monitoring Of Additive Manufacturing Using Digital Image Correlation,
2021
Embry-Riddle Aeronautical University
In-Situ Monitoring Of Additive Manufacturing Using Digital Image Correlation, Martina Jani
Doctoral Dissertations and Master's Theses
Advances in additive manufacturing over the past decade have led to applications in multiple fields. In particular, additive manufacturing answers the need for high flexibility in designing complex structures, however, the rapid thermal fluctuations during processing lead to numerous defects and processing-induced residual stresses. In this research, an in-situ approach using Digital Image Correlation (DIC) is developed to monitor the deformation during the processing, and thereby analyze the formation of defects and residual stresses. DIC is a visual technique that compares the changes in speckle pattern in consecutive images of a specimen to determine the displacements and strains. This research …
Reduced-Order Dynamic Modeling And Robust Nonlinear Control Of Fluid Flow Velocity Fields,
2021
Embry-Riddle Aeronautical University
Reduced-Order Dynamic Modeling And Robust Nonlinear Control Of Fluid Flow Velocity Fields, Anu Kossery Jayaprakash, William Mackunis, Vladimir Golubev, Oksana Stalnov
Publications
A robust nonlinear control method is developed for fluid flow velocity tracking, which formally addresses the inherent challenges in practical implementation of closed-loop active flow control systems. A key challenge being addressed here is flow control design to compensate for model parameter variations that can arise from actuator perturbations. The control design is based on a detailed reduced-order model of the actuated flow dynamics, which is rigorously derived to incorporate the inherent time-varying uncertainty in the both the model parameters and the actuator dynamics. To the best of the authors’ knowledge, this is the first robust nonlinear closed-loop active flow …
Kinematics Of Inter-Ply Interfaces In Composite Manufacturing,
2021
Embry-Riddle Aeronautical University
Kinematics Of Inter-Ply Interfaces In Composite Manufacturing, Sandeep Chava
Doctoral Dissertations and Master's Theses
The ubiquitous usage of polymer matrix composites in many applications demands a comprehensive understanding of composite interfaces and processing induced residual stresses, which critically affect both the manufacturing processes and the deformation mechanisms. Processing induced residual stresses are often responsible for causing warping, delamination, and dimensional instability in composite structures. This research includes new in-situ experimental approaches, cure cycle design, interface modification, and thermomechanical modeling for developing a fundamental understanding of the cure kinetics during composite manufacturing. Strains, ply-movement, and formation of defects are observed in-situ using digital image correlation (DIC) during the autoclave cure cycle for the first time. …
Development Of A Three Degree-Of-Freedom Control Simulation For A Group 3 Large Unmanned Aircraft System,
2021
Mississippi State University
Development Of A Three Degree-Of-Freedom Control Simulation For A Group 3 Large Unmanned Aircraft System, Majka Anna Wilczynski
Theses and Dissertations
Aircraft modeling and simulation has become increasingly important in the aviation world. Simulations allow for safer and more economical training prior to flight testing. In this project, a three degree-of-freedom control simulation coded in a MATLAB environment is used to assess and simulate the dynamic stability of group three unmanned aircraft system. By calculating, evaluating, and simulating the static and dynamic stability derivatives of the aircraft, this project will allow for the estimation of the handling qualities of an unmanned aircraft system. This can help mitigate risks that come along with altering the mass and aerodynamic properties of an aircraft, …
Enhancing Situational Awareness For Rotorcraft Pilots Using Virtual And Augmented Reality,
2021
Rowan University
Enhancing Situational Awareness For Rotorcraft Pilots Using Virtual And Augmented Reality, Ardit Pranvoku
Theses and Dissertations
Rotorcraft pilots often face the challenge of processing a multitude of data, integrating it with prior experience and making informed decisions in complex, rapidly changing multisensory environments. Virtual Reality (VR), and more recently Augmented Reality (AR) technologies have been applied for providing users with immersive, interactive and navigable experiences. The research work described in this thesis demonstrates that VR/AR are particularly effective in providing real-time information without detracting from the pilot's mission in both civilian and military engagements. The immersion of the pilot inside of the VR model provides enhanced realism. Interaction with the VR environment allows pilots to practice …
Utilizing Uas To Support Wildlife Hazard Management Efforts By Airport Operators,
2021
Embry-Riddle Aeronautical University
Utilizing Uas To Support Wildlife Hazard Management Efforts By Airport Operators, Flavio A. C. Mendonca, Ryan Wallace
Publications
The FAA requires airports operating under the Code of Federal Regulations Part 139 to conduct a wildlife hazard assessment (WHA) when some wildlife-strike events have occurred at or near the airport. The WHA should be conducted by a Qualified Airport Wildlife Biologist (QAWB) and must contain several elements, including the identification of the wildlife species observed and their numbers; local movements; daily and seasonal occurrences; and the identification and location of features on and near the airport that could attract wildlife. Habitats and land-use practices at and around the airport are key factors affecting wildlife species and the size of …
Lupa: An Excursion Vehicle For The Moons Of Mars,
2021
Kennesaw State University
Lupa: An Excursion Vehicle For The Moons Of Mars, Shannon Kavanagh, Bo Lewis, Alex Odinamba, Joshua Mulhern
Senior Design Project For Engineers
Our team has designed a spacecraft and mission for exploring the moons of Mars. The Lithological and Ultraviolet Photometry Assessment (LUPA) excursion vehicle is capable of crew habitation, autonomous rendezvous, and in-vacuum sample collection all in support of a parallel Mars surface mission to be carried out in the year 2040. Our project's key focus areas revolve around orbital mechanics, space vehicle propulsion analysis, scientific exploration, and the management of various interconnected spacecraft subsystems.
Project Scrappie (Clear Constellation),
2021
Kennesaw State University
Project Scrappie (Clear Constellation), Jacob Bertram, Jacob Britt, Bill Ngo, Mike Diesing
Senior Design Project For Engineers
Clear Constellation™ is a nationwide competition hosted by Rubicon® to combat the growing problem of space debris in Low Earth Orbit. Project Scrappie is our team’s solution to this problem. Scrappie is an autonomous apparatus will make use of Whipple shield technology to collide with debris at high velocities and effectively destroy the debris throughout selected orbital paths.
Stress Intensity Factor - Simple Solution For A Complex Problem,
2021
Embry-Riddle Aeronautical University
Stress Intensity Factor - Simple Solution For A Complex Problem, Hamid A. Ghassri, Alberto Mello
Beyond: Undergraduate Research Journal
This research explores the modeling of a cracked structure using a linear elastic finite element method (FEM) analysis with the objective of determining the stress intensity factor (SIF) for complex geometries. The analysis uses a mapping of the stress concentration area ahead of the crack tip to asymptotically determine the SIF. For model calibration, Irwin’s approximation method was used in two known crack case solutions subjected to a uniform tensile loading (Mode I – Opening) with fixed geometric dimensions. With focus on aircraft airworthiness application, two more complex geometries with irregular stress distributions were analyzed and the results were extracted …
