Engineering Commons^™

Nusat I Participant Photographs, Robert J. Twiggs

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Professor Bob Twiggs of the participants involved with the NUSat I program from January 3, 2013.

Cubesat Remote Data & Comms Transponders 145.825 Mhz, Bob Bruninga, Mirek Kasal, Mike Ruprecht

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint presentation created by Bob Bruninga, Mirek Kasal, and Mike Ruprecht titled "Cubesat Remote Data & Comms Transponders 145.825 MHz" from October 16, 2015.

Use Of Single Stage Model Rockets To Teach Some Engineering Principles And Practices To First Year Engineering And Engineering Technology Students, Hüseyin Sarper, Linda Vahala

Electrical & Computer Engineering Faculty Publications

Model rocketry has been called miniature astronautics; a technology in miniature, a hobby, a sport, a technological recreation, an educational tool, and it is all of these things. This paper will describe student projects using model rockets and engines to learn engineering principles for launching rockets and determining the apogee. Model rocketry is a powerful tool for instructors who wish to incorporate science, technology, engineering, and mathematics into a fun, engaging, and challenging activity for first year engineering students. The apogee can be determined using four distinct methods: trigonometry using hand held angle measuring tools, onboard altimeter devices, analytical calculations …

On Some Recent Experimental Results Concerning Turbulent Coanda Wall Jets, Caroline P. Lubert

Department of Mathematics and Statistics - Faculty Scholarship

The Coanda effect is the tendency of a stream of fluid to stay attached to a convex surface, rather than follow a straight line in its original direction. As a result, in such jets mixing takes place between the jet and the ambient air as soon as the jet issues from its exit nozzle, causing air to be entrained. This air-jet mixture adheres to the nearby surface. Whilst devices employing the Coanda effect usually offer substantial flow deflection, and enhanced turbulence levels and entrainment compared with conventional jet flows, these prospective advantages are generally accompanied by significant disadvantages including a …

Parameter Determination And Experimental Validation Of A Wire Feed Additive Manufacturing Model, Kannan Suresh Kumar

Masters Theses

“Laser metal deposition is an additive manufacturing method with great scope and robustness. The wire fed additive manufacturing method has great opportunities in space applications and other zero gravity manufacturing processes. Process parameters play an important role in controlling the complex phenomenon and obtaining an ideal manufactured part. These parameters can be efficiently determined using simulation tools which are highly essential in visualizing real world experiments, therefore saving time and experimental costs. The objective of this study is to develop a transient 3D model of laser aided wire feed metal deposition which realizes the heat transfer and fluid flow behavior …

Adjoint-Based Airfoil Shape Optimization In Transonic Flow, Joe-Ray Gramanzini

Masters Theses

"The primary focus of this work is efficient aerodynamic shape optimization in transonic flow. Adjoint-based optimization techniques are employed on airfoil sections and evaluated in terms of computational accuracy as well as efficiency. This study examines two test cases proposed by the AIAA Aerodynamic Design Optimization Discussion Group. The first is a two-dimensional, transonic, inviscid, non-lifting optimization of a Modified-NACA 0012 airfoil. The second is a two-dimensional, transonic, viscous optimization problem using a RAE 2822 airfoil. The FUN3D CFD code of NASA Langley Research Center is used as the ow solver for the gradient-based optimization cases. Two shape parameterization techniques …

Uncertainty Quantification Of Turbulence Model Closure Coefficients For Transonic Wall-Bounded Flows, John Anthony Schaefer

Masters Theses

"The goal of this work was to quantify the uncertainty and sensitivity of commonly used turbulence models in Reynolds-Averaged Navier-Stokes codes due to uncertainty in the values of closure coefficients for transonic, wall-bounded flows and to rank the contribution of each coefficient to uncertainty in various output flow quantities of interest. Specifically, uncertainty quantification of turbulence model closure coefficients was performed for transonic flow over an axisymmetric bump at zero degrees angle of attack and the RAE 2822 transonic airfoil at a lift coefficient of 0.744. Three turbulence models were considered: the Spalart-Allmaras Model, Wilcox (2006) k-ω Model, and the …

Discrete-Time Neural Network Based State Observer With Neural Network Based Control Formulation For A Class Of Systems With Unmatched Uncertainties, Jason Michael Stumfoll

Masters Theses

"An observer is a dynamic system that estimates the state variables of another system using noisy measurements, either to estimate unmeasurable states, or to improve the accuracy of the state measurements. The Modified State Observer (MSO) is a technique that uses a standard observer structure modified to include a neural network to estimate system states as well as system uncertainty. It has been used in orbit uncertainty estimation and atmospheric reentry uncertainty estimation problems to correctly estimate unmodeled system dynamics. A form of the MSO has been used to control a nonlinear electrohydraulic system with parameter uncertainty using a simplified …

Transient Thermoelectric Supercooling: Isosceles Current Pulses From A Response Surface Perspective And The Performance Effects Of Pulse Cooling A Heat Generating Mass, Alfred Piggott

Dissertations, Master's Theses and Master's Reports

With increased public interest in protecting the environment, scientists and engineers aim to improve energy conversion efficiency. Thermoelectrics offer many advantages as thermal management technology. When compared to vapor compression refrigeration, above approximately 200 to 600 watts, cost in dollars per watt as well as COP are not advantageous for thermoelectrics. The goal of this work was to determine if optimized pulse supercooling operation could improve cooling capacity or efficiency of a thermoelectric device. The basis of this research is a thermal-electrical analogy based modeling study using SPICE. Two models were developed. The first model, a standalone thermocouple with no …

A Comparison Of Combined Overlap Block Fuzzy Cognitive Maps (Cobfcm) And Combined Overlap Block Neutrosophic Cognitive Map (Cobncm) In Finding The Hidden Patterns And Indeterminacies In Psychological Causal Models: Case Study Of Adhd, Hojjatollah Farahani, Florentin Smarandache, Lihshing Leigh Wang

Branch Mathematics and Statistics Faculty and Staff Publications

In spite of researchers’ concerns to find causalities, reviewing the literature of psychological studies one may argue that the classical statistical methods applied in order to find causalities are unable to find uncertainty and indeterminacies of the relationships between concepts.

In this paper, we introduce two methods to find effective solutions by identifying “hidden” patterns in the patients’ cognitive maps. Combined Overlap Block Fuzzy Cognitive Map (COBFCM) and Combined Overlap Block Neutrosophic Map (COBNCM) are effective when the number of concepts can be grouped and are large in numbers. In the first section, we introduce COBFCM, COBNCM, their applications, and …

Magnus Effect In Duct Flow, Cameron W. Clarke, Jesse S. Batko, Kenneth W. Smith Jr.

Williams Honors College, Honors Research Projects

The following research paper details the preliminary research carried out by this team. The project was originally conceived to determine if Magnus Lift could be utilized in an unconventional way to assist rockets during takeoff. Several conceptual designs were proposed, but the idea was scrapped when it became apparent that the team would not be able to generate the desired lift without inducing significant amounts of drag and additional weight on a rocket. Instead, the team focused on researching an interesting topic that hasn’t been previously explored: Magnus lift on a cylinder within a duct. An experimental procedure that could …

Design Of The Structural And Propulsion Systems For The 2015 University Of Akron Rocket Team, Kyle W. Dehoff, Nicholas J. Hrusch

Williams Honors College, Honors Research Projects

No abstract provided.

Electric Field Modification Of A Diffusion Flame With Variable Electrode Geometry, Zachary Pinz

Summer Community of Scholars Posters (RCEU and HCR Combined Programs)

No abstract provided.

Microgravity Testing Of A Phase Change Reference On The International Space Station, T. Shane Topham, Gail E. Bingham, Harri Latvakoski, Igor Podolski, Vladimir S. Sychev, Andre Burdakin

Space Dynamics Laboratory Publications

Orbital sensors to monitor global climate change during the next decade require low drift rates for onboard thermometry, which is currently unattainable without on-orbit recalibration. Phase change materials (PCM), such as those that make up the ITS-90 standard, are seen as the most reliable references on the ground and could be good candidates for orbital recalibration. Space Dynamics Lab (SDL) has been developing miniaturized phase change references capable of deployment on an orbital blackbody for nearly a decade. To determine if and how microgravity will affect the phase transitions, SDL conducted experiments with ITS-90 standard material (gallium, Ga) on the …

Characterizing Noise Trends Of The Cross-Track Infrared Sounder (Cris), Bryce Walker, Mark Esplin, Ben Esplin, Deron Scott

Space Dynamics Laboratory Publications

Outline

• CrIS Summary

• Noise characterization process

• Noise trending results

• Recent Changes

• Conclusions

Dcgs: Image Processing, Screening, & Product Distribution Solution, Space Dynamics Laboratory

Space Dynamics Laboratory Publications

SCALABLE, CROSS-PLATFORM SOLUTION FOR NEAR REAL-TIME IMAGE PROCESSING, SCREENING, & PRODUCT DISTRIBUTION

SDL provides the Distributed Common Ground System (DCGS) community with a powerful image processing, screening, and product distribution solution by combining a ground station with the VANTAGE™ tactical intelligence software suite and the Sky Lynx data link interface hardware. This system's cost-effectiveness is achieved through the use of flexible and robust hardware configurations that enable the customer to scale the system to their DCGS program needs.

Buckling Instability Of Crown Sealing, J. O. Marston, Mohammad M. Mansoor, Tadd T. Truscott, S. T. Thoroddsen

Mechanical and Aerospace Engineering Faculty Publications

Despite the scholarly fascination with water entry of spheres for well over a century,¹ we present a new observation, namely, the crown-buckling instability. This instability is characterized by striations appearing near the top of the crown walls just prior to the surface seal, as shown in Fig. 1(a). The crown wall collapses inward due to the pressure differential across the wall created by the moving air in the wake of the sphere and surface tension within the crown. Since the rate of collapse is faster than that at which fluid drains out from the neck region, fluid collects into …

High Regression Rate Hybrid Rocket Fuel Grains With Helical Port Structures, Stephen A. Whitmore, Sean D. Walker, Daniel P. Merkley, Mansour Sobbi

Mechanical and Aerospace Engineering Faculty Publications

Results froma development campaign, where modern additive manufacturing methods are used to fabricate hybrid rocket fuel grains with embedded helical ports, are presented. The fuel grains were constructed from acrlyonitrile butadiene styrene using commercially available three-dimensional printer feedstockmaterial.Gaseous oxygen is used as the oxidizer for this test campaign.When compared to cylindrical fuel ports, significant increases in fuel regression rates were observed, and these increases in regression rate diminished with time as the helical fuel port burns to become progressivelymore cylindrical. Comparisons to the helical pipe flow skin friction correlation developed by Mishra and Gupta indicate that increased skin friction only …

Matryoshka Cavity, Randy Craig Hurd, T. Fanning, Zhao Pan, C. Maybey, Kyle G. Bodily, Kip Schafer Hacking, Nathan B. Spiers, Tadd T. Truscott

Mechanical and Aerospace Engineering Faculty Publications

When a water droplet impacts a free surface with sufficient velocity, the momentum transfer results in the formation of a hemispherical cavity expanding radially from the point of impact.¹ This cavity continues to expand until the kinetic energy is completely converted to potential energy (Fig. 1(a)).² Pumphrey and Elmore equated the potential energy of this subsurface cavity with the kinetic energy of the impacting droplet, concluding that the magnitude of the cavity radius is proportional to impact velocity and droplet diameter.³

Cubesat Wakes In The Earth’S Ionosphere, Robert M. Albarran Ii

Doctoral Dissertations and Master's Theses

Space exploration is currently being revolutionized by the advent of the CubeSat: 10cm cubed satellites that typically deploy in constellations for less than $100,000. Spacecraft instrumentation design must be redefined to abide by the compact CubeSat payload. Furthermore, the CubeSat dimension must be considered with respect to characteristic length scales of the space plasma environment, namely, the Debye length. Although spacecraft-plasma interactions- surface charging, plasma sheaths and wakes- have been well-studied for larger satellites, they are less understood for CubeSats.

The Dynamic Ionosphere CubeSat Experiment (DICE) is a 1.5U CubeSat which recently ended its mission. DICE carried two fixed-bias Langmuir …

Use Of Anaerobic Adhesive For Prevailing Torque Locking Feature On Threaded Product, Alan Hernandez

USF Tampa Graduate Theses and Dissertations

The purpose of this research is to determine if anaerobic adhesive can be used as a prevailing torque locking feature. Maintaining preload in critical joints is the usual standard that anaerobic adhesives are held to in aerospace and other industry. To test if anaerobic adhesive can be used as a prevailing torque locking feature a test procedure was developed and implemented to measure the removal torque of threaded fasteners after an allotted cure time. In total, 191 threaded fasteners of different material and coatings were tested in the unseated and seated states with various strengths and varieties of anaerobic adhesive. …

Space-Based Relative Multitarget Tracking, Keith Allen Legrand

Masters Theses

"Access to space has expanded dramatically over the past decade. The growing popularity of small satellites, specifically cubesats, and the following launch initiatives have resulted in exponentially growing launch numbers into low Earth orbit. This growing congestion in space has punctuated the need for local space monitoring and autonomous satellite inspection. This work describes the development of a framework for monitoring local space and tracking multiple objects concurrently in a satellite's neighborhood. The development of this multitarget tracking systems has produced collateral developments in numerical methods, relative orbital mechanics, and initial relative orbit determination.

This work belongs to a class …

Development Of Ionic Liquid Multi-Mode Spacecraft Micropropulsion Systems, Steven Paul Berg

Doctoral Dissertations

"This dissertation presents work on development of multi-mode specific spacecraft propulsion systems. Specifically, this work attempts to realize a single propellant capable of both chemical monopropellant and electric electrospray rocket propulsion, develop methods to characterize multi-mode propulsion system performance, and realize a system capable of both monopropellant and electrospray propulsion for a small spacecraft. Selection criteria for ionic liquid propellants capable of both monopropellant and electrospray propulsion are developed. These are based on desired physical properties and performance considering use in both propulsive modes. From these insights, a monopropellant mixture of 1-ethyl-3-methylimidazolium ethyl sulfate and hydroxylammonium nitrate is selected and …

Quantum Inspired Algorithms For Learning And Control Of Stochastic Systems, Karthikeyan Rajagopal

Doctoral Dissertations

"Motivated by the limitations of the current reinforcement learning and optimal control techniques, this dissertation proposes quantum theory inspired algorithms for learning and control of both single-agent and multi-agent stochastic systems.

A common problem encountered in traditional reinforcement learning techniques is the exploration-exploitation trade-off. To address the above issue an action selection procedure inspired by a quantum search algorithm called Grover's iteration is developed. This procedure does not require an explicit design parameter to specify the relative frequency of explorative/exploitative actions.

The second part of this dissertation extends the powerful adaptive critic design methodology to solve finite horizon stochastic optimal …

Ultra-Fast, Autonomous, Reconfigurable Communication System, Paul Bupe Jr

College of Graduate Studies: Theses & Dissertations

The recent years have witnessed an increase in natural disasters in which the destruction of essential communication infrastructure has significantly affected the number of casualties. In 2005, Hurricane Katrina in the United States resulted in over 1,900 deaths, three million land-line phones disconnections, and more than 2000 cell sites going out of service. This incident highlighted an urgent need for a quick-deployment, efficient communication network for emergency relief purposes. In this research, a fully autonomous system to deploy Unmanned Aerial Vehicles (UAVs) as the first phase disaster recovery communication network for wide-area relief is presented. As part of this system, …

Acoustic Emission Characteristics Of Damage Accumulation In Kevlar® 49 Composites, Eduardo Andrade

Open Access Theses & Dissertations

Acoustic emission (AE) data attained during tensile testing of epoxy impregnated Kevlar® 49 (K/Ep) composite strands were reduced and analyzed to monitor progressive damage accumulation during the approach to tensile failure. The K/Ep material tested in this study was chosen due to its similarity to the material-of-construction used in composite overwrapped pressure vessels (COPVs) used on the NASA Space Shuttle Orbiter. Insight into the progressive microstructural degradation of K/Ep strands was gained by monitoring AE event rate and energy. Source location based on energy attenuation and arrival time data was used to differentiate between significant AE attributable to microstructural damage …

Design Of A High Intensity Turbulent Combustion System, Mohammad Arif Hossain

Open Access Theses & Dissertations

In order to design next generation gas turbine combustor and rocket engines, a systematic study of flame structure at high intensity turbulent flow is necessary. The fundamental study of turbulent premixed combustion has been a major research concern for decades. The work is focused on the design and development of a high intensity turbulent combustion system which can be operated at compressible (0.3 < M < 0.5), preheated (T0=500K) and premixed conditions in order to investigate the 'Thickened Flame' regime. An air-methane mixture has been used as the fuel for this study. An optically accessible backward-facing step stabilized combustor has been designed for a maximum operating pressure of 6 bar. A grid has been introduced with different blockage ratios (BR = 54%, 61% & 67%) in order to generate turbulence inside the combustor for the experiment. Optical access is provided via quartz windows on three sides of the combustion chamber. Finite Element Analysis (FEA) is done in order to verify the structural integrity of the combustor at rated conditions. In order to increase the inlet temperature of the air, a heating section was designed to use commercially available in-line heaters. Separate cooling subsystems have been designed for chamber cooling and exhaust cooling. The LabVIEW software interface has been selected as the control mechanism for the experimental setup. A 10 kHz Time Resolved Particle Image Velocimetry (TR-PIV) system and a 3 kHz Planer Laser Induced Fluorescence (PLIF) system have been integrated with the system in order to diagnose the flow field and the flame respectively. The primary understanding of the flow field inside the combustor was achieved through the use of Detached Eddy Simulation (DES) by using commercially available software package ANSYS FLUENT. Preliminary validation is done by 10 kHz TR-PIV technique. Both qualitative and quantitative analysis have been done for CFD and experiment. Major flow parameters such as average velocity, fluctuation of velocity, kinetic energy, and turbulent intensity have been calculated for two distinct Reynolds number (Re = 815 & 3500). PIV results are compared with CFD results which show significant agreement with each other.

Design And Testing Of An Ox/Ch4 Swirl Torch Ignition System, Gabriel Ricardo Trujillo

Open Access Theses & Dissertations

NASA has renewed its interest in oxygen and methane as propellants for propulsion. Some of the reasons that drive this interest are the ease of storage of liquid methane when compared to hydrogen, the handling safety when compared to hypergols, in-situ resource utilization and its relative clean burning process. This project is part of the larger goal of the Center for Space Exploration Technology Research (cSETR) to better understand the aspects of using this propellants to create future hardware that are specifically optimized for their use. This paper discusses the testing of a previous iteration of the swirl torch igniter …

Uncertainty Estimates And Prediction Interval Development For Internal Strain Gage Balance Calibration Systems, Kenneth G. Toro

Mechanical & Aerospace Engineering Theses & Dissertations

Currently, there is a lack of the use of mathematically rigorous methods to evaluate the performance of multivariate force measurement systems. The specific problem addressed in the research stems from the practical issues faced by test engineers when wind tunnel models with internal strain gage balances are readied for test. Check loads are applied and the question that needs to be answered is whether or not the balance is reading within acceptable limits. These systems tend to be difficult to characterize uncertainty, primarily due to their multivariate nature, but also due to the desire for an estimate on the explanatory …

Electrospray Of An Energetic Ionic Liquid Monopropellant For Multi-Mode Micropropulsion Applications, Steven P. Berg, Joshua L. Rovey, Benjamin D. Prince, Shawn W. Miller, Raymond J. Bemish

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The multi-mode chemical-electric propulsion capable energetic ionic liquid propellant [Emim][EtSO4]-HAN is electro sprayed in a 100 µm capillary emitter to test the electric-mode performance of the propellant. The ionic liquid exhibits stable electrospray emission in both cation and anion extraction modes at a nominal extraction voltage of 3400 V. Near field measurements of current and mass flow rate distribution are taken at flow rates from 0.19 nL/s to 3.06 nL/s. Total emission current, as measured by Faraday cup and integrated, increases from 754 nA to 3195 nA for cation emission and from 552 nA to 2012 nA for anion emission. …