Aerospace Engineering Commons^™

Cnn Classification Architecture Study For Turbulent Free-Space And Attenuated Underwater Optical Oam Communications, Patrick L. Neary, Abbie T. Watnik, Kyle Peter Judd, James R. Lindle, Nicholas S. Flann

Space Dynamics Laboratory Publications

Turbulence and attenuation are signal degrading factors that can severely hinder free-space and underwater OAM optical pattern demultiplexing. A variety of state-of-the-art convolutional neural network architectures are explored to identify which, if any, provide optimal performance under these non-ideal environmental conditions. Hyperparameter searches are performed on the architectures to ensure that near-ideal settings are used for training. Architectures are compared in various scenarios and the best performing, with their settings, are provided. We show that from the current state-of-the-art architectures, DenseNet outperforms all others when memory is not a constraint. When memory footprint is a factor, ShuffleNet is shown to …

High Performance Thermal Straps For A Full Range Of Application Temperatures, M. Ralphs, M. Sinfield, M. Felt

Space Dynamics Laboratory Publications

Thermal straps are an essential component when using vibration sensitive instruments and cryocoolers in close proximity. Thermal straps conduct heat from the instrument to the cryocooler while limiting the amount of mechanical vibration the cryocooler transfers back to the instrument. Thermal straps are made from flexible, thermally conductive materials. Traditionally, they are made of metal – aluminum or copper, mostly – that has been formed into thin foils, wires, or braids to provide greater flexibility while still providing good thermal conductivity. These metallic straps, if made from pure metals, provide superior thermal performance at cryogenic temperatures ( < 60 K ) where their thermal conductivities peak to extraordinary levels. Pyrolytic graphite sheet (PG S) thermal straps have a thermal conductance that peaks at higher temperatures – approximately 160 K – and provide much higher mass-specific thermal conductance at temperatures above 60 K than metallic straps. This paper discusses the pros and cons of aluminum, copper, and PG S thermal straps along with different techniques to test their thermal and mechanical performance.

Transonic Small-Disturbance Theory/Integral Boundary Layer Airfoil Data For The Low-Fidelity Common Research Model, Jeffrey D. Taylor, Douglas Hunsaker

Browse all Datasets

Lift, Drag, and Moment Coefficient data for the Low-Fidelity Common Research Model wing airfoil sections.

Closed-Loop Propulsive Control For Very Low Perigee Orbit Energy Management And Stabilization, Tyler J. Gardner

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Within the past decade, the United States Air Force has begun exploring options for using smaller satellites, known as SmallSats and CubeSats, to decrease the time it takes to design and build new satellites. If used properly, a rapid development environment for satellites could improve the Air Force's ability to respond to new technologies and threats. Other organizations such as NASA and universities have been using SmallSats and CubeSats for research and development missions.

While smaller satellites are usually much cheaper to develop and require less time to create, limited volume strictly constrains the size of instrumentation and avionics that …

Analytic Guidance Strategies For Passively Safe Rendezvous And Proximity Operations, Simon Shuster

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A safety ellipse is a type of relative motion trajectory that is commonly used for unmanned rendezvous and proximity operations. As the name suggests, safety ellipses are passively safe relative motion trajectories, which means that their natural motion inherently maintains a low collision risk. The focus of this dissertation is the derivation, analysis, and application of guidance strategies that reconfigure, establish, and exit a safety ellipse. The guidance strategies consist of a set of ∆v vectors and impulse times, all written in closed form. Through applications of optimal control theory and parameter optimization, it is shown that these maneuver …

Modeling And Simulation Of A Supercritical Co2-Liquid Sodium Compact Heat Exchanger For Sodium Fast Reactors, Hailei Wang, Sean M. Kissick

Mechanical and Aerospace Engineering Faculty Publications

The study focuses on modeling and simulations of sodium-sCO2 intermediary compact heat exchangers for sodium-cooled fast reactors (SFR). A simplified 1-D analytical model was developed in companion with a 3-D CFD model. Using classic heat transfer correlations for Nusselt number, some simulation results using the 1-D model have achieved reasonable match with the CFD simulation results for longer channels (i.e., 40 cm and 80 cm). However, for short channel (10 cm) when axial conduction within the sodium fluid is significant, the 1-D model significantly over-predicted the heat transfer effectiveness. By incorporating the temperature-jump model, the 1-D model can extend its …

A General Approach To Lifting-Line Theory, Applied To Wings With Sweep, Jackson T. Reid

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Lifting-line theory is one simple method of predicting the lift produced by a wing. The traditional implementation of lifting-line theory, developed in 1918, is limited to predicting the lift of traditional straight wings. In this work, lifting-line theory is extended to predict the lift produced by modern swept (or "v-shaped") wings by strategically handling the singularities inherent to the theory. The resulting formulation is shown to be both accurate and computationally inexpensive, when compared to experimental and higher-fidelity computational results, demonstrating the method's usefulness as an aerodynamic design tool. Because of the low computational cost and accuracy of the method …

Improving Thermal Conduction Across Cathode/Electrolyte Interfaces In Solid-State Lithium-Ion Batteries By Hierarchical Hydrogen-Bond Network, Jinlong He, Lin Zhang, Ling Liu

Mechanical and Aerospace Engineering Student Publications and Presentations

Effective thermal management is an important issue to ensure safety and performance of lithium-ion batteries. Fast heat removal is highly desired but has been obstructed by the high thermal resistance across cathode/electrolyte interface. In this study, self-assembled monolayers (SAMs) are used as the vibrational mediator to tune interfacial thermal conductance between an electrode, lithium cobalt oxide (LCO), and a solid state electrolyte, polyethylene oxide (PEO). Embedded at the LCO/PEO interface, SAMs are specially designed to form hierarchical hydrogen-bond (H-bond) network with PEO. Molecular dynamics simulations demonstrate that all SAM-decorated interfaces show enhanced thermal conductance and dominated by H-bonds types. The …

Quantum Frontiers: To Boldly Go, Michael Dixon, Cali Christensen, Rachael Leisek

Space Dynamics Laboratory Publications

We have lift off!

Cali Christensen started her summer at Quantum Frontiers (QF) at an intern lunch. Seated around her were 20 other interns from universities all over the country who had been selected from a pool of over 900 applicants to participate in high-tech, space-related research endeavors pushing the boundaries of various fields such as engineering, mathematics, computer science, machine learning, and physics. Cali quickly realized after the first presentation that she may be one of the only non-engineer or scientists in the room. Her internship was different from any others that QF had yet sponsored. Instead of making …

Numerical Method For Rapid Aerostructural Design And Optimization, Jeffrey D. Taylor, Douglas F. Hunsaker

Mechanical and Aerospace Engineering Student Publications and Presentations

During early phases of wing design, analytic and low-fidelity methods are often used to identify promising design concepts. In many cases, solutions obtained using these methods provide intuition about the design space that is not easily obtained using higher-fidelity methods. This is especially true for aerostructural design. However, many analytic and low-fidelity aerostructural solutions are limited in application to wings with specific planforms and weight distributions. Here, a numerical method for minimizing induced drag with structural constraints is presented that uses approximations that apply to wings with arbitrary planforms and weight distributions. The method is applied to the NASA Ikhana …

3-D Printed Hybrid Propulsion Solutions For Smallsat Lunar Landing And Sample Return, Stephen A. Whitmore

Funded Research Records

No abstract provided.

Aerodynamic Interactions Of Synchronized Propellers, Nathan Welker, Samuel Johnson

Utah Space Grant Consortium

Emerging advances in electric-propulsion technology are enabling aircraft to use distributed electric propulsion (DEP) to increase efficiency and maneuverability. Distributed electric propulsion can also provide unique take-off and landing abilities which are not commonly found on traditional aircraft. The implementation of DEP effectively decreases the spacing between propellers, introducing complex aerodynamic interactions that are not well understood. This study aims to obtain experimental measurements of the flow fields of synchronized propellers at close-proximity in a side-by-side configuration using particle image velocimetry (PIV) in a wind tunnel. The results of this work will be focused on identifying the impact closely-spaced propellers …

Monte-Carlo Methods And The Step-Back Kalman Filter For Orbital State Estimation, Louis Tonc

Utah Space Grant Consortium

This research assesses the performance of filtering schemes for tracking uncooperative satellites through space-based optical measurements, and identifies a simple and numerically stable methodology that ameliorates the poor performance of standard filtering schemes at a substantially reduced cost in comparison to nonlinear particle filter-based remedies. Traditional filtering schemes, such as the extended Kalman filter (EKF) and unscented Kalman filter (UKF), both diverge when tracking a resident space object (RSO) in geosynchronous orbit (GEO) when there is a long time duration between measurements. This divergence is identified as a consequence of nonlinearity in the dynamics and nonlinearity in the optical measurements, …

Impact Of Parasitic Drag On A Family Of Optimal Lift Distributions, Austin J. Stewart

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Minimizing drag is a variational problem, and several minimum induced drag solutions have been found using different design constraints. The elliptic lift distribution is commonly used to minimize induced drag, but is only the optimal solution under one set of design constraints. Non-elliptic lift distributions are able to reduce induced drag, when compared to the elliptic lift distribution, by increasing the wingspan while maintaining a consistent wing–structure weight. However, these non-elliptic lift distributions are only optimal if the effects of viscous drag are neglected. In this study, numerical tools are used to estimate the total drag on rectangular wings that …

Practical Optical Survey Strategies For Near Geostationary Orbital Debris, Akhter Mahmud Nafi

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Uncontrolled space objects, more commonly known as space debris, consist of dead satellites, satellite deployment packages, and lost elements of these systems such as insulation blankets. These uncontrolled objects represent hazards to our nation’s most valuable space assets which include communication satellites, weather satellites, Earth monitoring systems, and military assets. To help mitigate this problem, this research proposes using the known astrodynamics of the near geosynchronous orbit (GEO) along with the known concentration of the uncontrolled GEO objects and observation constraints to design ground-based optical surveys that will detect uncatalogued debris. Furthermore, a scoring metric is developed to evaluate the …

Change Of Exposure Time Mid-Test In High Temperature Dic Measurement, Thinh Quang Thai, Adam J. Smith, Robert J. Rowley, Paul R. Gradl, Ryan B. Berke

Mechanical and Aerospace Engineering Faculty Publications

Performing digital image correlation (DIC) at extreme temperatures has been greatly challenging due to the radiation which saturates the camera sensor. At such high temperatures, the light intensity emitted from an object is occasionally so powerful that the acquired images are overwhelmingly saturated. This induces data loss, potentially ruining the test, thus requiring the user to restart the test. For this reason, selection of an appropriate camera sensitivity plays a crucial role prior to beginning the test. Exposure time is a factor contributing to camera sensitivity and it is the easiest setting to manipulate during the test since it introduces …

Linear Covariance Navigation Analysis Of Range And Image Measurement Processing For Autonomous Lunar Lander Missions, Randall Christensen, David Geller, Michael Hansen

Space Dynamics Laboratory Publications

Growing interest in autonomous landing on the lunar surface has motivated in-depth studies of the navigation architectures to support such missions. The research presented in this paper extends linear covariance models of terrain-relative navigation architectures to incorporate both image-based measurements to known landmarks and laser range measurements to the lunar surface. The benefit of the range measurements is shown to be significant in reducing relative position and velocity errors in the altitude channel, as compared to an image-only navigation architecture. The range measurements are also shown to reduce the sensitivity of final relative navigation errors to the turn-on time of …

Nytrox As “Drop-In” Replacement For Gaseous Oxygen In Smallsat Hybrid Propulsion Systems, Stephen A. Whitmore

Mechanical and Aerospace Engineering Faculty Publications

A medical grade nitrous oxide (N₂O) and gaseous oxygen (GOX) “Nytrox” blend is investigated as a volumetrically-efficient replacement for GOX in SmallSat-scale hybrid propulsion systems. Combined with 3-D printed acrylonitrile butadiene styrene (ABS), the propellants represent a significantly safer, but superior performing, alternative to environmentally-unsustainable spacecraft propellants like hydrazine. In a manner analogous to the creation of soda-water using dissolved carbon dioxide, Nytrox is created by bubbling GOX under pressure into N₂O until the solution reaches saturation. Oxygen in the ullage dilutes N₂O vapor and increases the required decomposition energy barrier by several orders …

Proper Orthogonal Decomposition And Recurrence Map For The Identification Of Spatial–Temporal Patterns In A Low-Re Wake Downstream Of Two Cylinders, Meihua Zhang, Zhongquan Charlie Zheng, Huixuan Wu

Mechanical and Aerospace Engineering Faculty Publications

Flow decomposition methods provide systematic ways to extract the flow modes, which can be regarded as the spatial distribution of a coherent structure. They have been successfully used in the study of wake, boundary layer, and mixing. However, real flow structures also possess complex temporal patterns that can hardly be captured using the spatial modes obtained in the decomposition. In order to analyze the temporal variation of coherent structures in a complex flow field, this paper studies the recurrence in phase space to identify the pattern and classify the evolution of the flow modes. The recurrence pattern depends on the …

New Constraint-Driven Mission Construct For Small Satellites And Constrained Missions, Lee Jasper, Barbara Braun, Lauren Hunt

Space Dynamics Laboratory Publications

Small satellites, though increasingly prevalent in the industry today, tend to not follow traditional development paths, technically or programmatically. In contrast to traditional requirements-driven missions, where meeting requirements is the primary metric of success, small satellite missions tend to be constraints-driven, where mission scope is tradable to maintain cost and schedule constraints.

Clean, Robust Alkali Sources By Intercalation Within Highly Oriented Pyrolytic Graphite, Rudolph N. Kohn Jr., Matthew S. Bigelow, Mary Spanjers, Benjamin K. Stuhl, Brian L. Kasch, Spencer E. Olson, Eric A. Imhof, David A. Hostutler, Matthew B. Squires

Space Dynamics Laboratory Publications

We report the fabrication, characterization, and use of rubidium vapor dispensers based on highly oriented pyrolytic graphite (HOPG) intercalated with metallic rubidium. Compared to commercial chromate salt dispensers, these intercalated HOPG (IHOPG) dispensers hold an order of magnitude more rubidium in a similar volume, require less than one-fourth the heating power, and emit less than one-half as many impurities. Appropriate processing permits exposure of the IHOPG to atmosphere for over ninety minutes without any adverse effects. Intercalation of cesium, potassium, and lithium into HOPG has also been demonstrated in the literature, which suggests that IHOPG dispensers may also be made …

Ground And In-Flight Calibration Of The Osiris-Rex Camera Suite, D. R. Golish, C. Drouet D'Aubigny, B. Rizk, D. N. Dellagiustina, P. H. Smith, K. Becker, N. Shultz, T. Stone, M. K. Barker, E. Mazarico, E. Tatsumi, R. W. Gaskell, L. Harrison, C. Merrill, C. Fellows, B. Williams, S. O'Dougherty, Michael Whitely, Jed Hancock, B. E. Clark, C. W. Hergenrother, D. S. Lauretta

Space Dynamics Laboratory Publications

The OSIRIS-REx Camera Suite (OCAMS) onboard the OSIRIS-REx spacecraft is used to study the shape and surface of the mission’s target, asteroid (101955) Bennu, in support of the selection of a sampling site. We present calibration methods and results for the three OCAMS cameras—MapCam, PolyCam, and SamCam—using data from pre-flight and in-flight calibration campaigns. Pre-flight calibrations established a baseline for a variety of camera properties, including bias and dark behavior, flat fields, stray light, and radiometric calibration. In-flight activities updated these calibrations where possible, allowing us to confidently measure Bennu’s surface. Accurate calibration is critical not only for establishing a …

Near-Field Pressure Signature Splicing For Low-Fidelity Design Space Exploration Of Supersonic Aircraft, Christian R. Bolander, Douglas F. Hunsaker

Mechanical and Aerospace Engineering Student Publications and Presentations

As interest in supersonic overland flight intensifies, new ways to meet government restrictions on sonic boom loudness must be implemented. Low-fidelity aerodynamic tools, such as PANAIR, can estimate the near-field pressure signature that ultimately determines the loudness of the sonic boom at the ground. These tools can greatly benefit the exploration of large design spaces due to their computational efficiency. One of the limitations of low-fidelity tools is the accuracy of the solution produced, which is dependent on the fundamental physical assumptions made in the development of the governing equations. If flow patterns are produced that severely violate these fundamental …

Diffraction Efficiency Measurement Instrument: Demi, Usu Department Of Mechanical And Aerospace Engineering

Mechanical and Aerospace Engineering

• We designed an automated system to do help QC technicians who currently check the efficiency of VPHGs by hand.

• Why should your reader be interested?

VPHGs are used in lab equipment and medical instruments and more. The largest VPHGs (like the ones the DEMI tests) are used in giant telescopes and other astronomical applications.

Biological Agent Dispersal And Containment, Austin Williams, Ryker Hacking, Weston Craig

Mechanical and Aerospace Engineering

Purpose

• Model the flow of airborne anthrax surrogate particles through a training facility

• Design a training facility that will safely contain all the released particles

• Determine final location of the particles within the testing facility

• Determine most influential factors for particle containment

Importance

• Training for a bio-terrorist threat

• Researching airborne flow of particles is necessary to prepare for a potential threat

• Response plans depend on timely determination of the containment zone

Ganging Multiple Mechanical Sun Trackers, Katie Clark, Ben Hansen, Ben Hill, Cody Kelley, Chris Twede

Mechanical and Aerospace Engineering

The scope of this project was to design a mechanical solar tracker that implemented the algorithm/patent developed by Dr. Nicholas Flann. The solar tracker needed to be able to gang with other units using a single motor. The designed tracking unit is intended to:

• Rotate 350 degrees

• Use 3 seasonal tracks to follow the sun

• Be adjustable for wind and snow loads

• Be constructed from readily available materials

Autonomous Fixed Wing Drone, Glen Wright, Case Haws, Duke Madson, Chandler Oaks, Cory Christensen, Ryan Mears, Mike Wells

Mechanical and Aerospace Engineering

Design an autonomous system for a fixed wing drone in order to fly a repeatable pattern for testing of RF communication equipment.

• Requirements:

– Fly a repeatable pattern

– 2 km range

– Transmit Telemetry points

– Switch between manual and autonomous

• Goals:

– Create a platform compatible with the second phase of the project

– Allow for autonomous takeoff and landing procedures

– Create a platform compatible with a host of airframes

Direct Pedal Actuation, Tyler Fallentine, Mitch Peterson, Bryce Fisher, Sam Hartvigsen, Alexander Bird

Mechanical and Aerospace Engineering

Problem Description:

• The Team shall deliver a working prototype for direct pedal actuation of the brake and throttle for use in remote control of a vehicle.

• The delivered design shall:

• Measure 15 in. by 9 in. by 13 in.

• Fit in 90% of tested vehicles.

• Meet force, speed, back drive force, etc.

• Install in under 10 minutes.

Mini Rad-Dx Product Update, Tyler Child, Bradly Payne, Colton Smart, Morgan Ward

Mechanical and Aerospace Engineering

Improve Current model by:

• Redesigning case to accommodate 3 – AA batteries

• Improve ingress protection to IP67

• Make device look more Rugged

• Eliminate one of the two LCD screens

• Design for injection molding production

• Develop a mobile app

Design, Build, Fly 2019-2020 Banner Towing Bush Plane, Brayden Barton, Carlton Collet, Talon Gamble, Daniel Gardner, Hayden Harmon, Daniel Scribner, Ryley Shingleton, Trevor Smith, Sabrina Snow

Mechanical and Aerospace Engineering

• Design: A bush plane capable of deploying and towing a banner in flight, carrying passengers, and taking off within 20 ft. Create simple systems capable of restraining the passengers and stowing, deploying, and releasing the banner.

• Build: The plane, passenger subsystem, and banner subsystem using durable and lightweight materials. Select a propulsion system with the necessary power and endurance to complete the missions.

• Fly: Three missions with the fastest lap times to achieve the highest score.

• Mission 1: Fly 3 laps within 5 minutes; take off in less than 20 ft.

• Mission …