L∞ Bounds For Transient Growth In Repetitive And Iterative Learning Control Systems,
2024
Missouri University of Science and Technology
L∞ Bounds For Transient Growth In Repetitive And Iterative Learning Control Systems, Douglas A. Bristow, John R. Singler
Mechanical and Aerospace Engineering Faculty Research & Creative Works
This paper revisits the problem of large transient growth in Iterative Learning Control (ILC) and Repetitive Process Control (RPC) systems. In ILC and RPC problems a process is repeated iteratively, with new control calculations occurring in between each iteration. Large transient growth refers to the propensity of some control algorithms to grow error exponentially before eventually converging. While robust monotonic convergence algorithms (in which monotonic convergence is guaranteed usually in exchange for a small loss in performance) have largely eliminated the concern for large transient growth in ILC, similar results cannot always be obtained in RPC. The emergence of additive …
Electrostatic Sorting Of Lunar Regolith Simulants For Sustainable Resource Utilization: Modeling And Characterization Of Particle Size Distribution,
2024
Missouri University of Science and Technology
Electrostatic Sorting Of Lunar Regolith Simulants For Sustainable Resource Utilization: Modeling And Characterization Of Particle Size Distribution, Abdullah Al Moinee, Peter Bachle, Kyle Newport, William Schonberg, David Bayless, Jeffrey Smith, Daoru Han, Fateme Rezaei
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
In pursuit of sustainable resource utilization on the Moon, this paper delves into modeling and characterization of particle size distribution (PSD) of lunar regolith simulants in an electrostatic system. A prototype electrostatic sieve was built and tested with four sample simulants mirroring properties of lunar mare and highland regolith. An alternating four-phase (90 degrees, 180 degrees, 270 degrees, 360 degrees) traveling square-wave was utilized for particle-directed transport to model the diverse trajectories of the particles. Numerically, we scrutinized how the distribution functions of the particles are manifested as the electrostatic field propagates, with a focus on three distinct particle ranges …
Fundamental Chemical Kinetic Experiments Of Combustion Products Inside A Shock Tube,
2024
University of Central Florida
Fundamental Chemical Kinetic Experiments Of Combustion Products Inside A Shock Tube, Alex-Abraham Pothen
Graduate Thesis and Dissertation 2023-2024
The use of lateral divert thrusters on hypersonic vehicles would allow for fine-tuned attitude control at high Mach numbers. However, the jet interaction effects of lateral thrusters on the hypersonic flow field have not been investigated thoroughly. Computational Fluid Dynamics (CFD) can provide preliminary modeling of the jet interaction, but several variables such as vehicle geometry, velocity, and altitude, result in computationally expensive modeling or loss in accuracy of the results. Therefore, the goal of chemical kinetics testing and chemical model verification is to enhance the fidelity of the jet interaction effects, specifically the plume reaction with air and the …
Modelling Of The Viscoelastic Relaxation Of A Stowed Telescope Starshade,
2024
University of Central Florida
Modelling Of The Viscoelastic Relaxation Of A Stowed Telescope Starshade, Rahul Raghu
Graduate Thesis and Dissertation 2023-2024
The Habitable Worlds Telescope Starshade is an occulting disk that orbits in tandem with a telescope that occludes and diffuses the light from stars to observe the relatively dim exoplanets in orbit around them. It achieves this in part with tailored petals that diffuse light to soften the light from the star. Due to the relative sizes of the star and the planet, NASA considers the shape stability of the Starshade's petals to be a Key Technology Gap. The Starshade is developed to be a deployable composite structure that folds on itself to fit within modern rockets. Due to the …
Mechanics Of Pure Bending And Eccentric Buckling In High-Strain Composite Structures,
2024
Old Dominion University
Mechanics Of Pure Bending And Eccentric Buckling In High-Strain Composite Structures, Jimesh D. Bhagatji, Oleksandr G. Kravchenko, Sharanabasaweshwara Asundi
Mechanical & Aerospace Engineering Faculty Publications
To maximize the capabilities of nano- and micro-class satellites, which are limited by their size, weight, and power, advancements in deployable mechanisms with a high deployable surface area to packaging volume ratio are necessary. Without progress in understanding the mechanics of high-strain materials and structures, the development of compact deployable mechanisms for this class of satellites would be difficult. This paper presents fabrication, experimental testing, and progressive failure modeling to study the deformation of an ultra-thin composite beam. The research study examines the deformation modes of a post-deployed boom under repetitive pure bending loads using a four-point bending setup and …
The Feasibility Of Motion Tracking Camera System For Magnetic Suspension Wind Tunnel Tests,
2024
Analytical Mechanics Associates
The Feasibility Of Motion Tracking Camera System For Magnetic Suspension Wind Tunnel Tests, Hisham M. Shehata, David Cox, Mark Schoenenberger, Colin Britcher, Eli Shellabarger, Timothy Schott, Brendan Mcgovern
Mechanical & Aerospace Engineering Faculty Publications
The Entry Systems Modeling (ESM) Program at NASA has actively participated in the re-development of the Magnetic Suspension Balance System (MSBS) at the six-inch subsonic wind tunnel at NASA Langley Research Center. This initiative aims to enhance the MSBS system's capabilities, enabling the testing of stingless entry vehicle models at supersonic speeds. To achieve this, control algorithms are required to ensure magnetic levitation control and stability for models during free-oscillation dynamic responses. Currently, the system relies on electromagnetic position sensors to provide real-time 3 degrees of freedom control of a rigid body. While this approach has proven successful for subsonic …
Restoration Of Strength In Polyamide Woven Glass Fiber Organosheets By Hot Pressing,
2024
Old Dominion University
Restoration Of Strength In Polyamide Woven Glass Fiber Organosheets By Hot Pressing, Mohammad Nazmus Saquib, Edwing Chaparro-Chavez, Christopher Morris, Kuthan Çelebi, Diego Pedrazzoli, Mingfu Zhang, Sergii G. Kravchenko, Oleksandr G. Kravchenko
Mechanical & Aerospace Engineering Faculty Publications
Thermoplastic composite organosheets (OSs) are increasingly recognized as a viable solution for automotive and aerospace structures, offering a range of benefits including cost-effectiveness through high-rate production, lightweight design, impact resistance, formability, and recyclability. This study examines the impact response, post-impact strength evaluation, and hot-pressing repair effectiveness of woven glass fiber nylon composite OSs across varying impact energy levels. Experimental investigations involved subjecting composite specimens to impact at varying energy levels using a drop-tower test rig, followed by compression-after-impact (CAI) tests. The results underscore the exceptional damage tolerance and improved residual compressive strength of the OSs compared to traditional thermoset composites. …
Enhancement Of The Performance And Emission Attributes For The Diesel Engine Using Diesel-Waste Cooking Oil Biodiesel And Graphene Oxide Nanofluid Blends Through Response Surface Methodology,
2024
Mechanical Power Engineering Departments, Faculty of Engineering, Tanta, University, Tanta, Egypt
Enhancement Of The Performance And Emission Attributes For The Diesel Engine Using Diesel-Waste Cooking Oil Biodiesel And Graphene Oxide Nanofluid Blends Through Response Surface Methodology, Medhat Elkelawy Prof. Dr. Eng., E A El Shenawy, Hagar Alm-Eldin Bastawissi, Mahmoud M. Shams
Mansoura Engineering Journal
This study examined how diesel fuel and waste-cooked oil (WCO) biodiesel blends added by various concentrations of graphene oxide (GO) nanoparticles can effect on the performance and emission characteristics of constant-speed, four-stroke, single-cylinder, water-cooled diesel engines. The GO nanoparticles concentrations are 50,100 and 150 ppm dispersed in different diesel-WCO biodiesel blends are pure diesel fuel (B0), 20% WCO biodiesel and 76% diesel fuel (B20), and 40% WCO biodiesel and 56% diesel fuel (B40). In addition 4% toluene in all blends which used as a surfactant. The diesel engine fueled with these blends and operated at various engine loads are 2, …
Kinetic Modeling Of Electrostatic Sieving For Lunar Regolith Beneficiation: Case Studies,
2024
Missouri University of Science and Technology
Kinetic Modeling Of Electrostatic Sieving For Lunar Regolith Beneficiation: Case Studies, Easton Ingram, Emmanuela Amen Eze, Jeffrey Smith, Fateme Rezaei, David Bayless, William Schonberg, Daoru Han
Materials Science and Engineering Faculty Research & Creative Works
A new kinetic particle modeling framework was developed to investigate electrostatic transport of lunar regolith particles with applications to the concept of electrostatic sieving. the new approach is based on kinetic particle dynamics and includes major modules of sampling the particle size distribution, solving electric fields, and tracking motion of charged dust grains. Case studies for a concept of electrostatic sieving were chosen to validate the new model. the simulation achieved similar yields reported in previous works, which served as validation of the model. the new model is computationally efficient and could serve as a design, analysis, and optimization tool.
Progress Of Lisap-Mse: A Concept Of Producing Aluminum In-Situ On The Moon Through Molten Salt Electrolysis,
2024
Missouri University of Science and Technology
Progress Of Lisap-Mse: A Concept Of Producing Aluminum In-Situ On The Moon Through Molten Salt Electrolysis, Jacob N. Ortega, David Bayless, Daniel Stutts, Daoru Han, Todd P. Sander, Jeffrey Smith, Fateme Rezaei, William Schonberg
Mechanical and Aerospace Engineering Faculty Research & Creative Works
This paper presents a concept of producing aluminum in-situ on the lunar surface, namely, the Lunar In-Situ Aluminum Production through Molten Salt Electrolysis (LISAP-MSE) method developed at Missouri University of Science and Technology. This paper aims to demonstrate the use of electro-deoxidation to reduce aluminum oxide (i.e., alumina) into aluminum and oxygen gas via electrolysis in a molten salt bath for the production of aluminum on the Moon. It is shown that with a steady supply of hydrogen chloride, this in-situ resource utilization (ISRU) method could supply several necessary materials consumed in the electro-deoxidation process except hydrogen chloride to produce …
Optimization Of High-Bypass Turbofan High-Pressure Compressor Blade – A Case Study,
2024
Kennesaw State University
Optimization Of High-Bypass Turbofan High-Pressure Compressor Blade – A Case Study, Adeel Khalid, Vlad Mandzyuk
The Kennesaw Journal of Undergraduate Research
This research determines the relationship between the High-Pressure Compressor (HPC) rotor blade design variables and compressor pressure ratio of a high bypass turbofan engine. Alterations in the HPC blades span, chord, taper, twist, number, and angle of incidence are performed and their effect on the HPC pressure ratio is observed. The objective is to determine key parameters that could maximize the performance of a high-pressure compressor for a given mission. Physics-based modeling, Computational Fluid Dynamics (CFD), and wind-tunnel testing are performed to compare and validate findings. Physics-based modeling is performed to serve as the benchmark for data obtained through other …
Winglet Vortex Optimization,
2024
Kennesaw State University
Winglet Vortex Optimization, Adeel Khalid, Anthony Gutierrez
The Kennesaw Journal of Undergraduate Research
The objective of this research is to determine the effect on aerodynamic performance due to changes of winglet design variables of the Boeing 737-700 aircraft. The various winglet types studied in this research include the blended, canted, wingtip fence and split scimitar. The variables include height, sweep angle, taper ratio, and inclination angle. These variables are altered in 5% increments from -15% to +15% of their original baseline values. Each altered winglet design only changes one variable at a time while keeping all other variables constant. The altered models are compared to the original by finding the aerodynamic efficiency through …
Gnss Software Defined Radio: History, Current Developments, And Standardization Efforts,
2024
Universitat der Bundeswehr Munchen
Gnss Software Defined Radio: History, Current Developments, And Standardization Efforts, Thomas Pany, Dennis Akos, Javier Arribas, M. Zahidul H. Bhuiyan, Pau Closas, Fabio Dovis, Ignacio Fernandez-Hernandez, Carles Fernandez-Prades, Sanjeev Gunawardena, Todd Humphreys, Zaher M. Kassas, Jose A. Lopez Salcedo, Mario Nicola, Mario L. Psiaki, Alexander Rugamer, Yong-Jin Song, Jong-Hoon Won
Faculty Publications
Taking the work conducted by the global navigation satellite system (GNSS) software-defined radio (SDR) working group during the last decade as a seed, this contribution summarizes, for the first time, the history of GNSS SDR development. This report highlights selected SDR implementations and achievements that are available to the public or that influenced the general development of SDR. Aspects related to the standardization process of intermediate-frequency sample data and metadata are discussed, and an update of the Institute of Navigation SDR Standard is proposed. This work focuses on GNSS SDR implementations in general-purpose processors and leaves aside developments conducted on …
Speculative Anisotropic Mesh Adaptation On Shared Memory For Cfd Applications,
2024
Old Dominion University
Speculative Anisotropic Mesh Adaptation On Shared Memory For Cfd Applications, Christos Tsolakis, Nikos Chrisochoides
Computer Science Faculty Publications
Efficient and robust anisotropic mesh adaptation is crucial for Computational Fluid Dynamics (CFD) simulations. The CFD Vision 2030 Study highlights the pressing need for this technology, particularly for simulations targeting supercomputers. This work applies a fine-grained speculative approach to anisotropic mesh operations. Our implementation exhibits more than 90% parallel efficiency on a multi-core node. Additionally, we evaluate our method within an adaptive pipeline for a spectrum of publicly available test-cases that includes both analytically derived and error-based fields. For all test-cases, our results are in accordance with published results in the literature. Support for CAD-based data is introduced, and its …
Investigations Of Performance And Emissions Of A Fischer-Tropsch Gtl Sustainable Aerospace Fuel With Lubricity Improver In A Compression Ignition Engine With Butanol Port Fuel Injection,
2024
Georgia Southern University
Investigations Of Performance And Emissions Of A Fischer-Tropsch Gtl Sustainable Aerospace Fuel With Lubricity Improver In A Compression Ignition Engine With Butanol Port Fuel Injection, James B. Willis
College of Graduate Studies: Theses & Dissertations
As there is increasing concern over emissions of traditional fossil fuels, as well as the future of continued reliance on this dwindling resource, it is becoming increasingly evident that alternative fuels are a necessity. This research investigates the use of a Fischer-Tropsch fuel from natural gas feedstocks, S8, in an internal combustion research engine with a common rail fuel injection system. This synthetic kerosene fuel has a high DCN of 62, indicating high affinity to autoignition compared to conventional pump diesel (ULSD) at 48 DCN. However, due to the process by which it is produced, this fuel lacks the necessary …
Experimentatal And Numerical Investigation Of Turbojet Engine Performance, Emissions, And Noise/Vibrations Using Jet-A And F24 Fuel,
2024
Georgia Southern University
Experimentatal And Numerical Investigation Of Turbojet Engine Performance, Emissions, And Noise/Vibrations Using Jet-A And F24 Fuel, John W. Mcafee Jr
College of Graduate Studies: Theses & Dissertations
Drastic improvement in cost effectiveness of high-power computing resources has generated a great interest numerical simulation to reduce the overhead cost of engine manufacturing, maintenance, and environmental concerns of engine testing. To accomplish this goal, this research presents the differences between military F24 fuel and commercial aviation fuel Jet-A from a thermochemical and engine performance perspective. This experimental data was used to create and validate a numerical model of the engine used in the experiments fueled with both Jet-A and F24 fuels. The experimental data was collected using a research based single stage turbojet engine outfitted with many sensors for …
Development Of A High-Pressure Infiltration Process For Phenol–Formaldehyde Matrix Composites,
2024
Missouri University of Science and Technology
Development Of A High-Pressure Infiltration Process For Phenol–Formaldehyde Matrix Composites, Samuel Weiler, Patrick Schwartzkopf, Henry Haffner, K. Chandrashekhara
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Phenol–formaldehyde (phenolic) thermosets are known for excellent heat and chemical resistance, high flame retardance, and good mechanical performance. However, phenolics are also known for their high brittleness, and tendency to form voids, due to a condensation reaction forming water during curing. These voids can decrease the mechanical performance of the resultant phenolic composite and introduce undesirable performance characteristics. This work aims to develop a technique that uses high-pressure infiltration to obtain dense phenolic matrix composites, with commercially available resin and fiber reinforcement. The high-pressure system developed in this work is compared to a conventional low-pressure resin infusion technique, and the …
Kinetic Simulations Of Dust Grain Charging Near Surfaces Under Various Plasma Conditions,
2024
Missouri University of Science and Technology
Kinetic Simulations Of Dust Grain Charging Near Surfaces Under Various Plasma Conditions, David Lund, Daoru Han
Mechanical and Aerospace Engineering Faculty Research & Creative Works
This paper presents fully kinetic numerical investigations of the charging of spherical and irregular shaped dust grains in multiple configurations utilizing the Parallel Immersed-Finite-Element Particle-in-Cell Dusty (PIFE-PIC-D) framework. The simulations account for both surface charging and in-depth charging of the dust grains immersed in various ambient plasma conditions near a floating or biased surface. PIFE-PIC-D explicitly resolves the geometrical and material properties (permittivity and photoelectron emissions) of each individual dust grain. PIFE-PIC-D will model self-consistently the unsteady and stochastic charging of grains directly from the deposition of electrons and ions onto them. PIFE-PIC-D will also simulate the charging of irregular-shaped …
Development And Characterization Of An Ion Source To Simulate Low Earth Orbit Plasma Environment In A Vacuum Chamber,
2024
Missouri University of Science and Technology
Development And Characterization Of An Ion Source To Simulate Low Earth Orbit Plasma Environment In A Vacuum Chamber, Emmanuel Kofi Asuako Wie-Addo, Scott Lucas, Daoru Han
Mechanical and Aerospace Engineering Faculty Research & Creative Works
A magnetic filter-type plasma source has been installed and characterized in a 10 ft long x 6ft diameter vacuum chamber. The plasma source was characterized with a fleet of diagnostic probes including an in-house cylindrical Langmuir probe. This resulted in the measurement of key plasma parameters such as electron number density, electron temperature, plasma potential, Debye length, ion current density, streaming ion energy, ion number density, and streaming ion velocity. By varying the flow rates, discharge current, and distance, single points measurements were taken at three locations downstream of the plasma source to establish an optimum operating condition to simulate …
Investigating Bistable Dynamics Of Coupled Oscillators With Similarities To Neural Activity In Epilepsy,
2024
Missouri University of Science and Technology
Investigating Bistable Dynamics Of Coupled Oscillators With Similarities To Neural Activity In Epilepsy, Nilay Kant, Ranjan Mukherjee
Mechanical and Aerospace Engineering Faculty Research & Creative Works
The dynamics of an oscillator, which exhibits a stable equilibrium and a stable limit cycle, is investigated. We refer to it as a bistable oscillator unit (BOU) and show that two coupled BOUs (CBOUs) exhibit dynamics analogous to neural activity patterns in epilepsy, including healthy, localized, and fully spread epileptic states. By treating each CBOU as an independent system influenced by the state of the other, we establish local input-to-state stability near the equilibrium and the limit cycle and estimate the ultimate bounds of the trajectories. Our analysis identifies the domain of the initial conditions and estimates the coupling parameter …
