Engineering Commons^™

An Enhanced Fuel Cell Dynamic Model With Electrochemical Phenomena Parameterization As Test Bed For Control System Analysis, Victor M. Fontalvo, George J. Nelson, Humberto A. Gomez, Marco E. Sanjuan

PRC-Affiliated Research

In this work, a model of a proton exchange membrane fuel cell (PEMFC) is presented. A dynamic performance characterization is performed to assess the cell transient response to input variables. The model used in the simulation considers three different phenomena: mass transfer, thermodynamics, and electrochemistry. The main sources of voltage loss are presented: activation, electrical resistance, and concentration. The model is constructed to avoid the use of fitted parameters, reducing the experimentation required for its validation. Hence, the electrochemical model is parameterized by physical variables, including material properties and geometrical characteristics. The model is demonstrated as a test-bed for PEMFC …

Incidence Of An Astronaut Not Sealing The Pressure Garment Visor On Reentry, Cameron M. Smith, Trent Tresch

Journal of Human Performance in Extreme Environments

Audiovisual records of a Project Mercury pilot’s activities during an orbital flight indicate that his visor was left open during reentry and descent to the sea surface, phases of flight during which cabin pressure loss was to be mitigated by suit pressurization; however, the suit could not have been pressurized with the visor open. Thus, for a presently unknown reason, a critical safety step—sealing the visor and making a pressure suit integrity test before reentry—was overlooked in this flight. Later, Space Shuttle flights were carried out with visors unsealed for much of the launch and landing phases, with the false …

Assessment Of Turbulence Models In A Hypersonic Cold-Wall Turbulent Boundary Layer, Junji Huang, Jorge-Valentino Bretzke, Lian Duan

Mechanical and Aerospace Engineering Faculty Research & Creative Works

In this study, the ability of standard one- or two-equation turbulence models to predict mean and turbulence profiles, the Reynolds stress, and the turbulent heat flux in hypersonic cold-wall boundary-layer applications is investigated. The turbulence models under investigation include the one-equation model of Spalart-Allmaras, the baseline k-ω model by Menter, as well as the shear-stress transport k-ω model by Menter. Reynolds-Averaged Navier-Stokes (RANS) simulations with the different turbulence models are conducted for a flat-plate, zero-pressure-gradient turbulent boundary layer with a nominal free-stream Mach number of 8 and wall-to-recovery temperature ratio of 0.48, and the RANS results are compared with those …

End-To-End Development Of A High-Altitude Pressure Vessel, Matthew Haskell, Erik Korzon, Elena Pradhan

Research Horizons Day Posters

No abstract provided.

Application Of Metamaterials For Multifunctional Satellite Bus Enabled Via Additive Manufacturing, Michael A. Macchia

Theses and Dissertations

Space systems require materials with superior stiffness to weight ratios to provide structural integrity while minimizing mass. Additive manufacturing processes enable the design of metamaterials that exceed the performance of naturally occurring materials in addition to allowing the integration of non-structural functions. This research explored the use of a high stiffness, high density, small melt pool track width AM material, Inconel 718, to enable the production of metamaterials with finer features possible than can possibly be created using a lower density aluminum alloy material. Various metamaterials were designed utilizing thin wall triply periodic minimal surface infilled sandwich structures. The performance …

Sweep And Taper Analysis Of Surfboard Fins Using Computational Fluid Dynamics, Brandon James Baldovin

Master's Theses

The research presented here provides a basis for understanding the hydrodynamics of surfboard fin geometries. While there have been select studies on fins there has been little correlation to the shape of the fin and its corresponding hydrodynamic performance. This research analyzes how changing the planform shape of a surfboard fin effects its performance and flow field. This was done by isolating the taper and sweep distribution of a baseline geometry and varying each parameter individually whilst maintaining a constant span and surface area. The baseline surfboard fin was used as a template in Matlab to generate a set of …

Emerging Need For A European Approach To Space Traffic Management, Tomas Hrozensky

Space Traffic Management Conference

The intensification of space activities worldwide, together with the emergence of new actors and disruptive concepts (e.g. miniaturized satellites, mega-constellations, in-orbit operations), create new challenges to ensure the safety and security of space systems and operations as well as the long-term sustainability of space activities. Among policy responses to these challenges, the development of a new approach to space traffic management was recently brought to the forefront by the adoption of a policy directive in this domain by the United States.

A comparable STM policy has not yet been developed in Europe even though considerations for the safety, security and …

Advanced Inflatable De-Orbit Solutions For Derelict Satellites And Orbital Debris, Aman Chandra, Greg Wilburn, Jekan Thanga

Space Traffic Management Conference

The exponential rise in small-satellites and CubeSats in Low Earth Orbit (LEO) poses important challenges for future space traffic management. At altitudes of 600 km and lower, aerodynamic drag accelerates de-orbiting of satellites. However, placement of satellites at higher altitudes required for constellations pose important challenges. The satellites will require on-board propulsion to lower their orbits to 600 km and let aerodynamic drag take-over. In this work we analyze solutions for de-orbiting satellites at altitudes of up to 3000 km. We consider a modular robotic de-orbit device that has stowed volume of a regular CubeSat. The de-orbit device would be …

End To End Satellite Servicing And Space Debris Management, Aman Chandra, Himangshu Kalita, Roberto Furfaro, Jekan Thanga

Space Traffic Management Conference

There is growing demand for satellite swarms and constellations for global positioning, remote sensing and relay communication in higher LEO orbits. This will result in many obsolete, damaged and abandoned satellites that will remain on-orbit beyond 25 years. These abandoned satellites and space debris maybe economically valuable orbital real-estate and resources that can be reused, repaired or upgraded for future use. Space traffic management is critical to repair damaged satellites, divert satellites into warehouse orbits and effectively deorbit satellites and space debris that are beyond repair and salvage. Current methods for on-orbit capture, servicing and repair require a large service …

Satellite Conjunction Assessment Risk Analysis For “Dilution Region” Events: Issues And Operational Approaches, Matthew D. Hejduk

Space Traffic Management Conference

An important activity within Space Traffic Management is the detection and prevention of possible on-orbit collisions between space objects. The principal parameter for assessing collision likelihood is the probability of collision, which is widely accepted among conjunction assessment practitioners; but it possesses a known deficiency in that it can produce a false sense of safety when the orbital position uncertainties for the conjuncting objects are high. The probability of collision is said to be “diluted” in such a situation and to understate the possible risk; certain approaches have been recommended by researchers to provide (largely conservative) risk estimates and remediation …

Space Objects Classification And Characterization Via Deep Learning And Light Curves: Applications To Space Traffic Management, Roberto Furfaro, Richard Linares, Vishnu Reddy

Space Traffic Management Conference

Recent advancements in deep learning (e.g. Convolutional Neural Networks (CNN), Recurrent Neural networks (RNN)) have demonstrated impressive results in many practical and theoretical fields (e.g. speech recognition, computer vision, robotics). Whereas deep learning methods are becoming ubiquitous, they have been barely explored in SSA applications, in particular with regard to object characterization for Space Traffic Management (STM).

In this paper, we report the results obtained in designing and training a set of CNNs and RNNs for Space Object (SO) classification and characterization using light-curve measurements. More specifically, we provide a comparison between deep networks trained on both physically-based models (i.e. …

Lasers For Communication And Coordination Control Of Spacecraft Swarms, Himangshu Kalita, Leonard Dean Vance, Vishnu Reddy, Jekan Thanga

Space Traffic Management Conference

Swarms of small spacecraft offer whole new capabilities in Earth observation, global positioning and communications compared to a large monolithic spacecraft. These small spacecraft can provide bigger apertures that increase gain in communication antennas, increase area coverage or effective resolution of distributed cameras and enable persistent observation of ground or space targets. However, there remain important challenges in operating large number of spacecrafts at once. Current methods would require a large number of ground operators monitor and actively control these spacecraft which poses challenges in terms of coordination and control which prevents the technology from scaled up in cost-effective manner. …

Near Real Time Satellite Event Detection And Characterization With Remote Photoacoustic Signatures, Justin Spurbeck, Moriba K. Jah

Space Traffic Management Conference

Active satellites frequently maneuver to mitigate conjunctions and maintain nominal mission orbits. With an ever-growing Resident Space Object (RSO) population, the need to detect and predict any changes in active RSO trajectories has become increasingly important. There is typically a lag on the order of hours to days from time of maneuver to unmodeled dynamic event detection depending on the magnitude of the delta-v. For uncooperative objects, this detection lag poses a threat to other satellites. Implementing an active photoacoustic signature change detection methodology to detect and predict unmodeled dynamic events would reduce the overall conjunction risk and provide a …

Astria Ontology: Open, Standards-Based, Data-Aggregated Representation Of Space Objects, Jennie Wolfgang, Kathleen Krysher, Michael Slovenski, Unmil P. Karadkar, Shiva Iyer, Moriba K. Jah

Space Traffic Management Conference

The necessity for standards-based ontologies for long-term sustainability of space operations and safety of increasing space flights has been well-established [6, 7]. Current ontologies, such as DARPA’s OrbitOutlook [5], are not publicly available, complicating efforts for their broad adoption. Most sensor data is siloed in proprietary databases [2] and provided only to authorized users, further complicating efforts to create a holistic view of resident space objects (RSOs) in order to enhance space situational awareness (SSA).

The ASTRIA project is developing an open data model with the goal of aggregating data about RSOs, parts, space weather, and governing policies in order …

Nanosat Tracking And Identification Techniques And Technologies, Mark A. Skinner

Space Traffic Management Conference

Nanosats (and CubeSats, ‘Smallsats’, etc.) are of order 10 cm in size, and are at or near the limits of what can be tracked and characterized, using existing space surveillance assets. Additionally, given the CubeSat form-factor, they are often launched in large numbers (scores), and can be virtually identical. Thus are they difficult to track and to identify.

We have identified a number of technologies that future nanosat missions could employ that would enhance the trackability and/or identification of their satellites when on-orbit. Some of these technologies require active illumination of the satellite with electromagnetic energy, either in the radio …

A Statistical Approach For Commercial Space Vehicle Integration Into The National Airspace System, Christopher Hays, Daniel Chu, Pedro Llanos

Space Traffic Management Conference

This paper explores commercial space vehicle (CSV) suborbital flight trajectories in the temporal and spatial domains for CSV integration into the National Airspace System. The research data was collected via the Suborbital Space Flight Simulator (SSFS) housed in the College of Aviation at Embry-Riddle Aeronautical University - Daytona Beach campus, and analyzed using an original MATLAB data analytics tool. This study primarily focuses on statistical trends observed in previously simulated flights supported by three Project PoSSUM (Polar Suborbital Science in the Upper Mesosphere) campaigns comprised of 34 flights and 19 control flights, and to identify relevant milestones in the CSV …

Human-In-The-Loop Landing Flare Flight Test Simulation Of The Spaceliner Orbiter, Frank Morlang

Space Traffic Management Conference

Against the background that all future air traffic participants are requested to act as System Wide Information Management (SWIM) communicating sub-systems by the future Single European Sky Air Traffic Management Research (SESAR) SWIM 'Intranet for ATM' concept, facing the challenge of integration of space traffic in the current Air Traffic Management (ATM) needs SWIM compliance of future commercial space transportation (CST) vehicles having “landing like an aircraft at an airport” characteristics. In order to evaluate future spacecraft cockpit procedures in a transition context from Aircraft Access to SWIM (AAtS) to Spacecraft Access to SWIM in a network wide airspace management …

Framework For Evaluating Traffic Management Services In Higher Airspace, Jennifer Gentry, Debra Moch-Mooney, Anuja Mahashabde

Space Traffic Management Conference

Flying faster, farther, longer and higher has always captured the public’s imagination. Yet there is a vast realm of airspace that remains unexplored, save for a handful of scientific and national security missions. It is a realm rife with extremes, where flights can reach multi-Mach speeds or stay aloft for months as they slowly circumnavigate the globe. It is a realm that lies high above the clouds, at the edge of space.

Recent breakthroughs in technology, fueled by a globalized economy and society’s appetite for information, have set the stage for routine commercial operations in this new realm. Companies, old …

Enhancing Suborbital Science Through Better Understanding Of Wind Effects, Pedro Llanos, Diane Howard

Space Traffic Management Conference

This paper highlights the importance of understanding some key factors, such as winds effects, trajectory and vehicle parameters variations in order to streamline the space vehicle operations and enhance science in the upper mesosphere at about 85 km. Understanding these effects is crucial to refine current space operations and establish more robust procedures. These procedures will involve training new space operators to conduct and coordinate space operations in class E above FL600 airspace within the Air Traffic Organization (ATO).

Space vehicles such as Space Ship Two can spend up to 6 minutes in class E airspace above FL600 after launch. …

Evaluation Of Unmanned Aircraft Flying Qualities Using A Stitched Learjet Model, Patrick M. Callaghan

Theses and Dissertations

In recent years, military UAVs have taken over missions that were too dull, dirty, or dangerous for manned aircraft. The increased demand has led to a build-fly-fix-fly development mentality, plaguing the early lifecycle with staggering mishap rates. Currently, MIL-STD-1797 lists flying qualities for UAVs as TBD, and the standards for manned fixed wing are inadequate when applied to UAVs. In an effort to expand the database of UAV flying qualities, an analysis was completed on a Simulink model of an LJ-25D developed from Calspans Variable Stability System aircraft at the United States Test Pilot School. Three maneuvers were simulated: (1) …

Magnetic Field Aided Indoor Navigation, William F. Storms

Theses and Dissertations

This research effort examines inertial navigation system aiding using magnetic field intensity data and a Kalman filter in an indoor environment. Many current aiding methods do not work well in an indoor environment, like aiding using the Global Positioning System. The method presented in this research uses magnetic field intensity data from a three-axis magnetometer in order to estimate position using a maximum – likelihood approach. The position measurements are then combined with a motion model using a Kalman filter. The magnetic field navigation algorithm is tested using a combination of simulated and real measurements. These tests are conducted using …

Aircraft-Runway Total Energy Measurement, Monitoring, Managing, Safety, And Control System And Method, Nihad E. Daidzic,

Aviation Department Publications

United States Patent, Patent Number US 10,202,204 B1, Date of Patent February 12, 2019.

A total runway safety system (TRSS) and method measures, monitors, manages, and informs flight crew on the progress of takeoffs and landings and of any hazardous runway conditions. In some embodiments, the TRSS measures, monitors, and informs flight crew of longitudinal and lateral runway tracks thus preventing overruns and veer-offs during takeoffs and landings. In some embodiments, backscatter of infrared laser beams emitted by the aircraft is used to evaluate groundspeed and the reflectivity of the runway surface to make estimates of the surface conditions, rough­ness …

Sure Abstract - Spring 2019: Biomimetic Metamaterial Scales Enhancing Thermal Coatings’ Mechanical Properties For Turbine Blades, Ryan Horton

Ryan Horton

No abstract provided.

Numerical Simulation Of Flushing Deposits In Pipelines, Joseph S. Coverston

FIU Electronic Theses and Dissertations

The purpose of this research is to reduce the amount of waste generated in Department of Energy nuclear cleanup efforts currently underway. Due to the highly radioactive nature of the waste, any fluid that contacts the waste must then be treated and processed as waste. To minimize the fluids contaminated during flushing, this research aims to provide a basis for the flushing of High Level Waste (HLW) pipelines. Edgar Plastic Kaolin (EPK) with solid particles of a nominal diameter of 1 micron was used as a simulacrum for HLW. An Eulerian-Eulerian simulation built in StarCCM+ software, with a k-ω turbulence …

Urban Flow And Small Unmanned Aerial System Operations In The Built Environment, Kevin A. Adkins

Kevin A. Adkins, PhD

The Federal Aviation Administration (FAA) has put forth a set of regulations (Part 107) that govern small unmanned aerial system (sUAS) operations. These regulations restrict unmanned aircraft (UA) from flying over people and their operation to within visual line of sight (VLOS). However, as new applications for unmanned aerial systems (UAS) are discovered, their capabilities improve, and regulations evolve, there is an increasing desire to undertake urban operations, such as urban air mobility, package delivery, infrastructure inspection, and surveillance. This built environment poses new weather hazards that include enhanced wind shear and turbulence. The smaller physical dimensions, lower mass and …

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W&B Problems For Far/Cs 25 Airplanes Tutorial, Nihad E. Daidzic

Aviation Department Publications

Weight and Balance (W&B) computations are essential step in ensuring that the aircraft (in this case FAR/CS 25 Transport-category airplanes) is properly loaded with its Center of Mass (CM) of Center of Weight/Gravity (CG) in the proper range.

A Higher-Order Method Implemented In An Unstructured Panel Code To Model Linearized Supersonic Flows, Jake Daniel Davis

Master's Theses

Since their conception in the 1960s, panel codes have remained a critical tool in the design and development of air vehicles. With continued advancement in computational technologies, today's codes are able to solve flow fields around arbitrary bodies more quickly and with higher fidelity than those that preceded them. Panel codes prove most useful during the conceptual design phase of an air vehicle, allowing engineers to iterate designs, and generate full solutions of the flow field around a vehicle in a matter of seconds to minutes instead of hours to days using traditional CFD methods. There have been relatively few …

Electrical/Chemical Thruster Using The Same Monopropellant And Method, Steven P. Berg, Joshua L. Rovey

Mechanical and Aerospace Engineering Faculty Research & Creative Works

A thruster operable in a chemical mode or in an electrospray mode using the same liquid monopropellant for operation in both modes is described having a multiplicity of a microthrusters made of a catalytic material having a bore therethrough, where, when operated in the chemical mode, the microthrusters are heated to decompose the monopropellant the monopropellant flows therethrough to generate relatively high thrust. An extractor is positioned downstream of the outlet ends of the microthrusters, such that when the system is operated in its electrospray mode the flowrate of the monopropellant through the microthrusters is substantially lower than in the …

Educating The Space Scientists At Embry-Riddle Through Design, Build And Fly Rocketry Experience, Pedro Llanos, Robert E. Haley, Sathya Gangadharan

Pedro J. Llanos (www.AstronauticsLlanos.com)