Aerospace Engineering Commons^™

Direct Simulation And Reduced-Order Modeling Of Premixed Flame Response To Acoustic Modulation, Zheng Qiao

Theses and Dissertations

This dissertation introduces a general, predictive and cost-efficient reduced-order modeling (ROM) technique for characterization of flame response under acoustic modulation. The model is built upon the kinematic flame model–G-equation to describe the flame topology and dynamics, and the novelties of the ROM lie in i) a procedure to create the compatible base flow that can reproduce the correct flame geometry and ii) the use of a physically-consistent acoustic modulation field for the characterization of flame response. This ROM addresses the significant limitations of the classical kinematic model, which is only applicable to simple flame configurations and relies on ad-hoc models …

Vertical Take-Off And Landing Control Via Dual-Quaternions And Sliding Mode, Joshua Sonderegger

Doctoral Dissertations and Master's Theses

The landing and reusability of space vehicles is one of the driving forces into renewed interest in space utilization. For missions to planetary surfaces, this soft landing has been most commonly accomplished with parachutes. However, in spite of their simplicity, they are susceptible to parachute drift. This parachute drift makes it very difficult to predict where the vehicle will land, especially in a dense and windy atmosphere such as Earth. Instead, recent focus has been put into developing a powered landing through gimbaled thrust. This gimbaled thrust output is dependent on robust path planning and controls algorithms. Being able to …

An Accurate And Computationally Efficient Method For Battery Capacity Fade Modeling, D. M. Ajiboye, Jonathan W. Kimball, R.(Robert) G. Landers, John (T.) Park

Electrical and Computer Engineering Faculty Research & Creative Works

The Industry Demand for Accurate and Fast Algorithms that Model Vital Battery Parameters, E.g., State-Of-Health, State-Of-Charge, Pulse-Power Capability, is Substantial. One of the Most Critical Models is Battery Capacity Fade. the Key Challenge with Physics-Based Battery Capacity Fade Modeling is the High Numerical Cost in Solving Complex Models. in This Study, an Efficient and Fast Model is Presented to Capture Capacity Fade in Lithium-Ion Batteries. Here, the High-Order Chebyshev Spectral Method is Employed to Address the Associated Complexity with Physics-Based Capacity Fade Models. its Many Advantages, Such as Low Computational Memory, High Accuracy, Exponential Convergence, and Ease of Implementation, Allow …

Numerical Investigations Of 2-D Magnetic Nozzles On Pulsed Plasma Plumes, Joshua Daniel Burch

Masters Theses

"This research presents studies of a novel type of magnetic nozzle that allows for three-dimensional (3-D) steering of a plasma plume. Numerical simulations were performed using Tech-X's USim® software to quantify the nozzle's capabilities. A2-D planar magnetic nozzle was applied to plumes of a nominal pulsed inductive plasma (PIP) source with discharge parameters similar to those of Missouri S&T's Missouri Plasmoid Experiment (MPX). Argon and xenon plumes were considered. Simulations were verified and validated through a mesh convergence study as well as comparison with available experimental data. Periodicity was achieved over the simulation run time and phase angle samples were …

Recent Analytic Development Of The Dynamic Q-Tensor Theory For Nematic Liquid Crystals, Xiang Xu

Mathematics & Statistics Faculty Publications

Liquid crystals are a typical type of soft matter that are intermediate between conventional crystalline solids and isotropic fluids. The nematic phase is the simplest liquid crystal phase, and has been studied the most in the mathematical community. There are various continuum models to describe liquid crystals of nematic type, and Q-tensor theory is one among them. The aim of this paper is to give a brief review of recent PDE results regarding the Q-tensor theory in dynamic configurations.

Editorial For The Special Issue On Micromachines For Non-Newtonian Microfluidics, Lanju Mei, Shizhi Qian

Mechanical & Aerospace Engineering Faculty Publications

In lieu of an abstract, this is an excerpt from the first page.

Microfluidics has seen a remarkable growth over the past few decades, with its extensive applications in engineering, medicine, biology, chemistry, etc [...]

On The Implementation And Further Validation Of A Time Domain Boundary Element Method Broadband Impedance Boundary Condition, Fang Q. Hu, Douglas M. Nark

Mathematics & Statistics Faculty Publications

A time domain boundary integral equation with Burton-Miller reformulation is presented for acoustic scattering by surfaces with liners in a uniform mean flow. The Ingard-Myers impedance boundary condition is implemented using a broadband multipole impedance model and converted into time domain differential equations to augment the boundary integral equation. The coupled integral-differential equations are solved numerically by a March-On-in-Time (MOT) scheme. While the Ingard-Myers condition is known to support Kelvin-Helmholtz instability due to its use of a vortex sheet interface between the flow and the liner surface, it is found that by neglecting a second derivative term in the current …

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 …

Exploring Dft+U Parameter Space With A Bayesian Calibration Assisted By Markov Chain Monte Carlo Sampling, Pedram Tavadze, Reese Boucher, Guillermo Avendaño-Franco, Keenan X. Kocan, Sobhit Singh, Viviana Dovale-Farelo, Wilfredo Ibarra-Hernández, Matthew B. Johnson, David S. Mebane, Aldo H. Romero

Faculty & Staff Scholarship

The density-functional theory is widely used to predict the physical properties of materials. However, it usually fails for strongly correlated materials. A popular solution is to use the Hubbard correction to treat strongly correlated electronic states. Unfortunately, the values of the Hubbard U and J parameters are initially unknown, and they can vary from one material to another. In this semi-empirical study, we explore the U and J parameter space of a group of iron-based compounds to simultaneously improve the prediction of physical properties (volume, magnetic moment, and bandgap). We used a Bayesian calibration assisted by Markov chain Monte Carlo …

The Return To Anisotropy Across A Jet In Crossflow, Gregory P. Sakradse

Dissertations and Theses

With data from experiments on a jet of air emitting from an orifice flush with the floor of a wind tunnel providing a transverse flow, analysis is conducted to extract information about the state of anisotropy in the Reynolds stress tensor. Inflow velocities are modulated across two distinct turbulence intensity regimes while holding jet exit conditions constant, providing an opportunity to isolate effects of both jet to crossflow velocity ratio, r and the effects of the turbulence carried by the crossflow. Anisotropy in the Reynolds stress tensor is examined through anisotropy invariant maps and evolution of the function F, …

High-Order Positivity-Preserving L2-Stable Spectral Collocation Schemes For The 3-D Compressible Navier-Stokes Equations, Johnathon Keith Upperman

Mathematics & Statistics Theses & Dissertations

High-order entropy stable schemes are a popular method used in simulations with the compressible Euler and Navier-Stokes equations. The strength of these methods is that they formally satisfy a discrete entropy inequality which can be used to guarantee L₂ stability of the numerical solution. However, a fundamental assumption that is explicitly or implicitly used in all entropy stability proofs available in the literature for the compressible Euler and Navier-Stokes equations is that the thermodynamic variables (e.g., density and temperature) are strictly positive in the entire space{time domain considered. Without this assumption, any entropy stability proof for a numerical scheme …

Development And Applications Of Adjoint-Based Aerodynamic And Aeroacoustic Multidisciplinary Optimization For Rotorcraft, Ramiz Omur Icke

Mechanical & Aerospace Engineering Theses & Dissertations

Urban Air Mobility (UAM) is one of the most popular proposed solutions for alleviating traffic problems in populated areas. In this context, the proposed types of vehicles mainly consist of rotors and propellers powered by electric motors. However, those rotary-wing components can contribute excessively to noise generation. Therefore, a significant noise concern emerges due to urban air vehicles in or around residential areas. Reducing noise emitted by air vehicles is critically important to improve public acceptance of such vehicles for operations in densely populated areas.

Two main objectives of the present dissertation are: (1) to expand the multidisciplinary optimization to …

Soarnet, Deep Learning Thermal Detection For Free Flight, Jake T. Tallman

Master's Theses

Thermals are regions of rising hot air formed on the ground through the warming of the surface by the sun. Thermals are commonly used by birds and glider pilots to extend flight duration, increase cross-country distance, and conserve energy. This kind of powerless flight using natural sources of lift is called soaring. Once a thermal is encountered, the pilot flies in circles to keep within the thermal, so gaining altitude before flying off to the next thermal and towards the destination. A single thermal can net a pilot thousands of feet of elevation gain, however estimating thermal locations is not …

One Dimensional Study Of Magnetoplasmadynamic Thrusters For A Potential New Class Of Heavy Ion Drivers For Plasma Jet Driven Magnetoinertial Fusion, Patrick M. Brown

Theses and Dissertations

Plasma Jet Driven Magnetoinertial Fusion (PJMIF) requires high velocity heavy ion drivers in order to compress a magnetized target to fusion conditions. Previous work with heavy ion drivers has revealed sub-par accelerations due to plasma instabilities; thus, it is necessary to investigate new methods of heavy ion plasma acceleration. One such method is Magnetoplasmadynamic (MPD) thrusters. Past studies of these thrusters have been conducted at an initial temperature at or below the energy of full ionization. Here MPD thrusters are investigated using a Godunov type MHD solver with a Harten-Lax van Leer-D (HLLD) flux solving scheme assuming the plasma is …

Plasma Aerodynamics: Experimental Quantification Of The Lift Force Generated On An Airfoil Using Plasma Actuation To Estimate Power Requirements In Small Uav Applications, Getachew Ashenafi

UNLV Theses, Dissertations, Professional Papers, and Capstones

This research addressed the amount of electric power required to induce specific changes in lift force using a NACA 2127 airfoil with a chord length of ~28 mm, connected to a micro load cell, in a wind tunnel of 103 square centimeter cross-section. A DBD plasma actuator supplied by a ZVS driven high voltage pulsed DC circuit, operating at a frequency of 17.4 kHz, was utilized for voltages of up to 5000 V. Two configurations of electrode gapping were compared to determine the efficient use of power. The configuration with a gap of ~1 mm between the upstream and downstream …

Investigation Of Trajectory And Control Designs For A Solar Sail To The Moon, Michelle Nadeau

Doctoral Dissertations and Master's Theses

NASA’s Artemis program and other government and commercial projects are working toward establishing a sustainable human presence on the moon. This thesis investigates the technical feasibility of a solar sail-based spacecraft (sailcraft) as a low-cost method of delivering cargo or science instruments to the moon and demonstrates how this sailcraft could be controlled to change its orbit. The concept is a low-cost, commercial launch vehicle-deployable, CubeSat-based sailcraft with a square sail, assumed attitude control, and a small payload traversing from low-Earth orbit toward the moon with zero propellant use. In this thesis, methods for sailcraft to increase altitude, the trajectory …

Comparing Radiation Shielding Potential Of Liquid Propellants To Water For Application In Space, John Czaplewski

Master's Theses

The radiation environment in space is a threat that engineers and astronauts need to mitigate as exploration into the solar system expands. Passive shielding involves placing as much material between critical components and the radiation environment as possible. However, with mass and size budgets, it is important to select efficient materials to provide shielding. Currently, NASA and other space agencies plan on using water as a shield against radiation since it is already necessary for human missions. Water has been tested thoroughly and has been proven to be effective. Liquid propellants are needed for every mission and also share similar …

Impendance Probe Payload Development For Space-Based Joint Service Collaboration, Brian T. Kay

Theses and Dissertations

Collaborations utilizing small spacecraft in near earth orbit between the U. S. Coast Guard Academy (CGA), Naval Research Lab (NRL), the U. S. Naval Academy (USNA), and the Air Force Institute of Technology (AFIT) have initiated scientific and engineering space-based experiments. Sourced opportunities like the VaSpace ThinSat missions have provided a platform for payload, sensor, and experiment development that would have otherwise been resource prohibitive. We have constructed an impedance probe payload derived from the existing ‘Space PlasmA Diagnostic suitE’ (SPADE) mission operating from NASA’s International Space Station. Currently both space and laboratory plasmas are investigated with AC impedance measurements …

Neuromorphic Vision Sensors For Space-Based Applications, Jessica L. Horn

Theses and Dissertations

This research examines the viability of event-based vision (neuromorphic) sensors for future use on satellites. Outputting single pixel events only when a change in intensity is detected, event-based vision sensors offer a potential low power, low latency, high temporal resolution, and high dynamic range solution as compared to traditional CCD or CMOS camera technology. The commercial off-the-shelf DVS240C sensor, is analyzed to determine if operability is affected by launch conditions and the low Earth space environment through vacuum, thermal vacuum, and vibration tests. No appreciable changes in sensor operation was observed throughout testing. Additionally, the sensor was able to detect …

Numerical Reconstruction Of Spalled Particle Trajectories In An Arc-Jet Environment, Raghava S. C. Davuluri, Sean C. C. Bailey, Kaveh A. Tagavi, Alexandre Martin

Mechanical Engineering Faculty Publications

To evaluate the effects of spallation on ablative material, it is necessary to evaluate the mass loss. To do so, a Lagrangian particle trajectory code is used to reconstruct trajectories that match the experimental data for all kinematic parameters. The results from spallation experiments conducted at the NASA HYMETS facility over a wedge sample were used. A data-driven adaptive methodology was used to adapts the ejection parameters until the numerical trajectory matches the experimental data. The preliminary reconstruction results show that the size of the particles seemed to be correlated with the location of the ejection event. The size of …

Molten Regolith Electrolysis Processing For Lunar Isru: Financial And Physics Analysis Of Spacex Starship Transportation, Cheyenne Harper

Honors Undergraduate Theses

The purpose of the following research is to explore molten regolith electrolysis (MRE) methodology for in-situ resource utilization (ISRU) of Highlands lunar regolith, to be explored during the initial Artemis missions. An analysis of potential commercial launch providers for MRE-equipment based on technology-readiness level (TRL), payload mass support, and $ USD/kg payload price is provided. SpaceX is ultimately proposed as a launch provider of MRE equipment following multi-factorial analysis, with the SpaceX Starship human landing system (HLS) variant proposed for supporting MRE payload. Finally, customers of regolith-derived oxygen, aluminum, and silicon are distinguished to form the business case for operating …

Fluid-Wall Interactions In Pseudopotential Lattice Boltzmann Models, Cheng Peng, Luis F. Ayala, Orlando M. Ayala

Engineering Technology Faculty Publications

Designing proper fluid-wall interaction forces to achieve proper wetting conditions is an important area of interest in pseudopotential lattice Boltzmann models. In this paper, we propose a modified fluid-wall interaction force that applies for pseudopotential models of both single-component fluids and partially miscible multicomponent fluids, such as hydrocarbon mixtures. A reliable correlation that predicts the resulting liquid contact angle on a flat solid surface is also proposed. This correlation works well over a wide variety of pseudopotential lattice Boltzmann models and thermodynamic conditions.

Nebulizer-Based Systems To Improve Pharmaceutical Aerosol Delivery To The Lungs, Benjamin M. Spence

Theses and Dissertations

Combining vibrating mesh nebulizers with additional new technologies leads to substantial improvements in pharmaceutical aerosol delivery to the lungs across therapeutic administration methods. In this dissertation, streamlined components, aerosol administration synchronization, and/or Excipient Enhanced Growth (EEG) technologies were utilized to develop and test several novel devices and aerosol delivery systems. The first focus of this work was to improve the poor delivery efficiency, e.g., 3.6% of nominal dose (Dugernier et al. 2017), of aerosolized medication administration to adult human subjects concurrent with high flow nasal cannula (HFNC) therapy, a form of continuous-flow non-invasive ventilation (NIV). The developed Low-Volume Mixer-Heater (LVMH) …

Foundations Of The Geometric Mechanics Udwadia-Kalaba Framework For Rigid Body Constrained Motion Analysis, Brennan S. Mccann

Doctoral Dissertations and Master's Theses

Presented herein are multiple tools for constrained motion analysis extended to different dynamical frameworks. The Udwadia-Kalaba (UK) formalism for the constrained motion analysis of a point mass is a well-documented and applied methodology. Here, UK formulation is generalized to the dynamics of rigid bodies on nonlinear manifolds in the geometric mechanics framework. This approach simultaneously treats rotational and translational motion in a unified method without encountering singularites or non-uniqueness, issues that would arise were attitude parameterization sets used. The viability of this geometric mechanics UK formalism is demonstrated for the cases of fully and underconstrained systems. The nominal UK formalism …

Finite-Time State Estimation For An Inverted Pendulum Under Input-Multiplicative Uncertainty, Sergey V. Drakunov, William Mackunis, Anu Kossery Jayaprakash, Krishna Bhavithavya Kidambi, Mahmut Reyhanoglu

Publications

A sliding mode observer is presented, which is rigorously proven to achieve finite-time state estimation of a dual-parallel underactuated (i.e., single-input multi-output) cart inverted pendulum system in the presence of parametric uncertainty. A salient feature of the proposed sliding mode observer design is that a rigorous analysis is provided, which proves finite-time estimation of the complete system state in the presence of input-multiplicative parametric uncertainty. The performance of the proposed observer design is demonstrated through numerical case studies using both sliding mode control (SMC)- and linear quadratic regulator (LQR)-based closed-loop control systems. The main contribution presented here is the rigorous …

Studies Of Two-Phase Flow With Soluble Surfactant, Ryan Peter Atwater

Dissertations

Numerical methods are developed for accurate solution of two-phase flow in the zero Reynolds number limit of Stokes flow, when surfactant is present on a drop interface and in its bulk phase interior. The methods are designed to achieve high accuracy when the bulk Péclet number is large, or equivalently when the bulk phase surfactant has small diffusivity

In the limit of infinite bulk Péclet number the advection-diffusion equation that governs evolution of surfactant concentration in the bulk is singularly perturbed, indicating a separation of spatial scales. A hybrid numerical method based on a leading order asymptotic reduction in this …

A Study Of The Design Of Adaptive Camber Winglets, Justin J. Rosescu

Master's Theses

A numerical study was conducted to determine the effect of changing the camber of a winglet on the efficiency of a wing in two distinct flight conditions. Camber was altered via a simple plain flap deflection in the winglet, which produced a constant camber change over the winglet span. Hinge points were located at 20%, 50% and 80% of the chord and the trailing edge was deflected between -5° and +5°. Analysis was performed using a combination of three-dimensional vortex lattice method and two-dimensional panel method to obtain aerodynamic forces for the entire wing, based on different winglet camber configurations. …

Laser Shock Peening Pressure Impulse Determination Via Empirical Data-Matching With Optimization Software, Colin C. Engebretsen

Theses and Dissertations

Laser shock peening (LSP) is a form of work hardening by means of laser induced pressure impulse. LSP imparts compressive residual stresses which can improve fatigue life of metallic alloys for structural use. The finite element modeling (FEM) of LSP is typically done by applying an assumed pressure impulse, as useful experimental measurement of this pressure impulse has not been adequately accomplished. This shortfall in the field is a current limitation to the accuracy of FE modeling, and was addressed in the current work. A novel method was tested to determine the pressure impulse shape in time and space by …

Characterization Of A Plasma Source Simulating Solar Wind Plasma In A Vacuum Chamber, Blake Anthony Folta

Masters Theses

"The United States has set an aggressive time line to not only return to the Moon, but also to establish a sustained human presence. In the Apollo missions dust was a significant factor, but the duration of those missions was short so dust and surface charging were problems, but they did not pose an immediate threat. For a long-term mission, these problems instead become incredibly detrimental. Because of this, research needs to be conducted to investigate these phenomena so that mitigation techniques can be developed and tested. To this end, this thesis serves to demonstrate the Gas and Plasma Dynamics …

Developing A Uas-Deployable Methane Sensor Using Low-Cost Modular Open-Source Components, Gavin Demali

Williams Honors College, Honors Research Projects

This project aimed to develop a methane sensor for deployment on an unmanned aerial system (UAS), or drone, platform. This design is centered around low cost, commercially available modular hardware components and open source software libraries. Once successfully developed, this system was deployed at the Bath Nature Preserve in Bath Township, Summit County Ohio in order to detect any potential on site fugitive methane emissions in the vicinity of the oil and gas infrastructure present. The deliverables of this project (i.e. the data collected at BNP) will be given to the land managers there to better inform future management and …