Aerospace Engineering Commons^™

High-Throughput: An Approach For Simultaneous Creep Testing Of Nuclear Structural Alloys, Raushan Singh

Student Research Symposium

Creep is a time-dependent deformation at constant load and elevated temperature.

It is widely used in an application that involves high temperature under load for e.g., Nuclear reactors.

Creep tests are notoriously slow, taking weeks/months to complete one experiment.

• This makes High-Throughput techniques more desirable

Our Goals:

(1) Demonstrate novel High-Throughput methods to perform more creep tests more quickly

(2) Apply those methods to more quickly characterize 3D printed 316L (future work)

Uncertainty Quantification In Neural Networks For Cfd, Cody Grogan

Student Research Symposium

Neural Networks have surged to popularity in many fields because of their ability to model complex functions. However, for most scientists, this comes at the cost of interpretability.

The aim of this research is to compile the different methods to uncertainty quantification in Neural Networks and apply them to a CFD problem.

Understanding Lightning Damage Formation In A Carbon-Epoxy Pultruded Rod Stitched Efficient Unitized Structure (Prseus) Composite, Dounia Boushab, Aniket Mote, Khari Harrison, Juhyeong Lee, Charles U. Pittman Jr., Thomas E. Lacy Jr.

Mechanical and Aerospace Engineering Faculty Publications

Lightning damage to composite aircraft structures results from a concurrent and sequential interaction between arc discharge multi-physics and the anisotropic electrical and thermal composite properties. In this study, the impact of nominal 50 and 125 kA lightning strikes on damage formation in a carbon-epoxy Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS) was investigated. A combination of visual inspection, ultrasonic phased array testing, destructive sectioning, and various microscopy techniques was employed to characterize the damage. Localized damage, including severe matrix decomposition, melting of polyester warp-knitting yarns, fiber splitting, and large-scale delamination, was confined to the immediate vicinity of the lightning attachment …

Generalized Linear Targeting For Cislunar Flight, David Geller, Brayden Barton, David Woffinden

Space Dynamics Laboratory Publications

An important element of Artemis and NASA’s campaign to explore the Moon is the autonomous onboard two-level targeter (TLT) used during all cislunar flight phases. The function of the TLT is to autonomously recompute the burn targets for the upcoming burn (or multiple burns) in response to navigation and vehicle dispersion providing a solution that meets all trajectory constraints. Although the TLT has been utilized previously as a ground-based planning tool, and flown onboard during the Artemis I mission, it’s complexity and iterative nature make is difficult to incorporate into and support rapid analyses such as robust optimal trajectory design …

Evaluation Of First-Order Actuator Dynamics And Linear Controller For A Bio-Inspired Rotating Empennage Fighter Aircraft, Benjamin C. Moulton, Matthew W. Harris, Douglas F. Hunsaker, James J. Joo

Mechanical and Aerospace Engineering Student Publications and Presentations

This paper considers the problem of stabilizing a bio-inspired fighter aircraft variant at its Air Combat Maneuver Condition. The aircraft equations of motion are linearized, and an infinite-horizon linear quadratic regulator design is conducted for this aircraft. Included in the dynamics are first-order actuator models, which have the effect of slowing actuator responses. This is particularly important for the bio-inspired variant because it requires rotation of the empennage, which has relatively large inertia. The bio-inspired variant open-loop system is unstable in the short period and Dutch roll modes, which is mitigated in the closed-loop system. Monte Carlo simulation responses to …

Stick-Fixed Maneuver Points In Roll, Pitch, And Yaw And Associated Handling Qualities, Benjamin C. Moulton, Troy A. Abraham, Douglas F. Hunsaker

Mechanical and Aerospace Engineering Student Publications and Presentations

The stick-fixed pitch maneuver point is an important measure of aircraft longitudinal dynamic response and handling quality characteristics, and includes effects of both aerodynamic and inertia properties of the aircraft about the pitch axis. In the present work, the existence of stick-fixed roll and yaw maneuver points is demonstrated, which are determined from the lateral forces, moments, and inertial properties of the aircraft. These stick-fixed roll and yaw maneuver points are directly related to the predicted lateral handling qualities. Example results are included for several aircraft that demonstrate the importance of this parameter when predicting the dynamic response of the …

Target Size Estimation Through Sensor Fusion, Morgan Davidson, Cory Brinck, Kori Moore, Tanner Chase

Space Dynamics Laboratory Publications

Target size is an important quantity in both classification and multi-sensor target tracking applications, but it is often an unknown. In some imaging applications, target size is assumed based on classification results. This assumed size is sometimes used in the synthesis of range measurements from monocular imagery, based on the apparent target size that is observed. Range-from-apparent-size measurements may be the only range measurements available during times when sensors that produce range information (such as radar) are not available. This range-from-apparent-size approach is typically plagued by range bias in the resulting measurements due to several factors. In this work, we …

Orbit Determination Demonstration Using Onboard One-Way Radiometrics From The Iris Radio On The Capstone Mission, Todd A. Ely, Anthony Zara, Dana Sorensen, Zaid J. Towfic, Connor Ott, Alec Forsman, John D. Baker

Space Dynamics Laboratory Publications

Onboard one-way radiometric tracking from an Iris Radio paired with a Chip Scale Atomic Clock (CSAC) on NASA’s CAPSTONE mission has been collected and demonstrated to be able to determine its near rectilinear halo orbit. This is a first-ever demonstration of one-way radiometric tracking originating from the DSN and being collected onboard a spacecraft. For CAPSTONE, the tracking data from the Iris/CSAC pair are shown to have sufficient accuracy to enable future autonomous radio navigation for missions with modest navigation requirements. This work will compare the space-based data with prior ground-based test results, as well as assess CAPSTONE’s orbit solution …

On The History And Semantics Of Burble In Aerodynamic Theory, Benjamin C. Moulton, Cory D. Goates, Troy A. Abraham

Mechanical and Aerospace Engineering Student Publications and Presentations

The term burble has been in use in aerodynamic theory for over a century. While burble may be unfamiliar to most contemporary aerodynamicists, the word has a rich history based in aerodynamic theory and experimentation. The present paper outlines the fluidity of burble's meaning over time. From analyzing subsonic flow over an airfoil, to the implementation of stochastic turbulence in aircraft carrier landing simulations, the term burble has had a significant impact on the study of aerodynamics. The term burble has fallen out of use in aerodynamic engineering circles. Why did this happen? And what can be learned from the …

Modeling Of Frontal Polymerization Of Carbon Fiber And Dicyclopentadiene Woven Composites With Stochastic Material Uncertainty, Ahmadreza Mohammad Sharifi, Dong-Jun Kwon, S. Z. H. Shah, Juhyeong Lee

Mechanical and Aerospace Engineering Faculty Publications

A novel finite element modeling framework is proposed for simulating dicyclopentadiene (DCPD) frontal polymerization in carbon fiber (CF) woven composites. A mesoscale CF/DCPD representative volume element (RVE) model was developed with two triggering directions, resulting in out-of-plane and in-plane DCPD polymerization. The Arrhenius equation coupled with a modified Prout-Tompkins autocatalytic model was used to evaluate the dynamic DCPD polymerization process. The rate and degree of DCPD cure were calculated by the material property uncertainties of DCPD with and without random void inclusions (3% used as a reference in this work). The DCPD frontal polymerization in CF/DCPD composite was strongly influenced …

Experimental And Modelling Of Lightning Damage To Carbon Fibre-Reinforced Composites Under Swept Stroke, Chengzhao Kuang, Kunkun Fu, Juhyeong Lee, Huixin Zhu, Qizhen Shi, Xiaoyu Cui

Mechanical and Aerospace Engineering Faculty Publications

Lightning swept stroke creates multiple lightning attachments along an aircraft in flight. This introduces distinct structural damage compared to that from a single-point lightning current injection test in laboratory. This study presents both experimental and numerical studies on lightning damage in carbon fibre-reinforced polymer (CFRP) composites under swept stroke. Coupled electrical–thermal finite element (FE) models were proposed to predict lightning damage to CFRP composites under single-point current injection and swept stroke, respectively. A lightning swept stroke testing method was proposed by embedding a copper wire inside the composites to simulate multiple lightning attachments on the composites. The FE-predicted damage from …

Development Of A Potassium Permanganate Catalyst-Infused Fuel Grain For Hydrogen Peroxide Hybrid Thruster Ignition Enhancement, Ryan J. Thibaudeau

All Graduate Theses and Dissertations, Fall 2023 to Present

This thesis describes and addresses the need for reliable ignition in small satellite hybrid propulsion systems using hydrogen peroxide. It describes process of creating custom 3D printed ABS plastic fuel grains with small amounts of catalysts. These catalysts lead to a more reliable and energy-efficient ignition of a hybrid rocked propulsion system using catalyst-infused ABS and high-test hydrogen peroxide (HTP). Hydrogen peroxide is a high-density oxidizer and therefore more volumetrically efficient for a small satellite using hybrid rocket technology when compared to gaseous oxygen (GOX). The traditional ignition methods of hybrid rocket propulsion systems using HTP are compared to and …

In-Situ Optical Measurements Of High Temperature Combustion Plumes, Cara Frischkorn

All Graduate Theses and Dissertations, Fall 2023 to Present

Rocket motors are critical to the human exploration of space and to the United States missile defense systems. The design and manufacturing of these motors requires extensive simulation and testing to assure the motors will perform as intended and to minimize safety risks. Taking data from inside the rocket motors during tests is extremely difficult due to the intense temperatures inside the motor as it burns; most instrumentation cannot survive in this environment. The research discussed in this thesis aims to develop an instrumentation system composed of a fiberoptic cable which conducts light from the interior of a rocket motor …

Molecular Dynamics Simulations Of The Spontaneous Deformation And Auxetics Behavior During Tensile Test Of A Nematic Liquid Crystal Elastomer Model, Haoran Wang, Nanang Mahardika

Browse all Datasets

Nematic liquid crystal elastomers (LCEs) are advanced materials known for their shape-changing capability in response to external stimuli such as heat, light and electromagnetic fields. This makes them excellent candidates for applications like soft robotics and energy harvesting. While studies on their physical behavior have shed light on the complex nonlinear mechanics of LCEs, investigations through all-atom molecular dynamics (MD) simulations remain an underutilized avenue compared to experimental and theoretical analyses. This limited use is primarily due to the lack of well-established frameworks for conducting high-fidelity atomistic simulations of LCEs. To bridge this gap, we introduce an all-atom MD simulation …

Towards A Virtual Test Framework To Predict Residual Compressive Strength After Lightning Strikes, Scott L.J. Millen, Xiaodong Xu, Juhyeong Lee, Suparno Mukhopadhyay, Michael R. Wisnom, Adrian Murphy

Mechanical and Aerospace Engineering Faculty Publications

A novel integrated modelling framework is proposed as a set of coupled virtual tests to predict the residual compressive strength of carbon/epoxy composites after a lightning strike. Sequentially-coupled thermal-electric and thermo-mechanical models were combined with Compression After Lightning Strike (CAL) analyses, considering both thermal and mechanical lightning strike damage. The predicted lightning damage was validated using experimental images and X-ray Computed Tomography. Delamination and ply degradation information were mapped to a compression model, with a maximum stress criterion, using python scripts. Experimental data, in which artificial lightning strike and compression testing were performed, was used to assess the predictive capabilities …

On Quantifying Uncertainty In Lightning Strike Damage Of Composite Laminates: A Hybrid Stochastic Framework Of Coupled Transient Thermal-Electrical Simulations, R. S. Chahar, J. Lee, T. Mukhopadhyay

Mechanical and Aerospace Engineering Faculty Publications

Lightning strike damage can severely affect the thermo-mechanical performance of composite laminates. It is essential to quantify the effect of lightning strikes considering the inevitable influence of material and geometric uncertainties for ensuring the operational safety of aircraft. This paper presents an efficient support vector machine (SVM)-based surrogate approach coupled with computationally intensive transient thermal-electrical finite element simulations to quantify the uncertainty in lightning strike damage. The uncertainty in epoxy matrix thermal damage and electrical responses of unprotected carbon/epoxy composite laminates is probabilistically quantified considering the stochasticity in temperature-dependent multi-physical material properties and ply orientations. Further, the SVM models are …

Cislunar Navigation Techniques And Navigation Performance Optimization, Quinn P. Moon

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Nova-C is a lunar lander developed by the private company Intuitive Machines to deliver commercial payloads to the Moon. The IM-1 mission set for 2023 will launch and land the Nova-C near the Moon's south pole. In this research, various navigation techniques are explored to determine the lander's position and velocity during key segments. This process is studied for key mission events including trajectory correction maneuvers (TCMs), lunar orbit insertion (LOI), and descent orbit insertion (DOI). Each mission segment, referred to as an Orbit Determination Segment (OD), is analyzed with three different navigation techniques: Monte Carlo Analysis, Linear Covariance Analysis, …

Time-Orbiting-Potential Chip Trap For Cold Atoms, C. A. Sackett, J. C. Stickney

Space Dynamics Laboratory Publications

We present a design for an atom chip trap that uses the time-orbiting-potential technique. The design offers several advantages compared with other chip-trap methods. It uses a simple crossed-wire pattern on the chip, along with a rotating bias field. The trap is naturally close to spherically symmetric, and it can be modified to be exactly symmetric in quadratic order of the coordinates. Loading from a magneto-optical trap is facilitated because the trap can be positioned an arbitrary distance from the chip. The fields can be modified to provide a gradient for support against gravity, and the three-dimensional trap can be …

Model-Assisted Online Optimization Of Gain-Scheduled Pid Control Using Nsga-Ii Iterative Genetic Algorithm, Shen Qu, Tianyi He, Guoming Zhu

Mechanical and Aerospace Engineering Faculty Publications

In the practical control of nonlinear valve systems, PID control, as a model-free method, continues to play a crucial role thanks to its simple structure and performance-oriented tuning process. To improve the control performance, advanced gain-scheduling methods are used to schedule the PID control gains based on the operating conditions and/or tracking error. However, determining the scheduled gain is a major challenge, as PID control gains need to be determined at each operating condition. In this paper, a model-assisted online optimization method is proposed based on the modified Non-Dominated Sorting Genetic Algorithms-II (NSGA-II) to obtain the optimal gain-scheduled PID controller. …

A Geometrical, Reachable Set Approach For Constrained Pursuit–Evasion Games With Multiple Pursuers And Evaders, Olli Jansson, Matthew W. Harris

Mechanical and Aerospace Engineering Faculty Publications

This paper presents a solution strategy for deterministic time-optimal pursuit–evasion games with linear state constraints, convex control constraints, and linear dynamics that is consistent with linearized relative orbital motion models such as the Clohessy–Wiltshire equations and relative orbital elements. The strategy first generates polytopic inner approximations of the players’ reachable sets by solving a sequence of convex programs. A bisection method then computes the optimal termination time, which is the least time at which a set containment condition is satisfied. The pursuit–evasion games considered are games with (1) a single pursuer and single evader, (2) multiple pursuers and a single …

Multiscale Damage Modelling Of Notched And Un-Notched 3d Woven Composites With Randomly Distributed Manufacturing Defects, S.Z.H. Shah, Juhyeong Lee, P.S.M. Megat-Yusoff, Syed Zahid Hussain, T. Sharif, R.S. Choudhry

Mechanical and Aerospace Engineering Faculty Publications

This work proposes a stochastic multiscale computational framework for damage modelling in 3D woven composite laminates, by considering the random distribution of manufacturing-induced imperfections. The proposed method is demonstrated to be accurate, while being simple to implement and requiring modest computational resources. In this approach, a limited number of cross-sectional views obtained from micro-computed tomography (µCT) are used to obtain the stochastic distribution of two key manufacturing-induced defects, namely waviness and voids. This distribution is fed into a multiscale progressive damage model to predict the damage response of three-dimensional (3D) orthogonal woven composites. The accuracy of the proposed model was …

Low-Erosion Nozzle Materials For Long-Duration Hybrid Rocket Burns, Russell S. Babb

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Hybrid rocket systems, which employ a solid fuel grain and a liquid oxidizer, are a low-cost and environmentally friendly alternative to traditional rocket systems. However, hybrid rockets suffer from an increased nozzle throat erosion rate, which impacts motor performance and reliability. To address this issue several materials and low-erosion nozzle configurations were tested. The results of the testing campaign produced a nozzle that reduce the throat erosion rate five-fold.

Augmented State Linear Covariance Applications For Nonlinear Missile Engagements, Jeffrey Scott Clawson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Sustained actuator saturation is a common occurrence for missile engagements. The saturation nonlinearity creates some difficulty for high-fidelity linear analysis methods. This dissertation investigates three methods of modeling actuator saturation in an advanced linear analysis. The linear covariance tools from this dissertation run extremely fast and provide several advantages over other linear missile engagement analysis methods. First, a simulation is developed and validated for a target engagement scenario without actuator saturation. Next, saturations are introduced to the problem, along with the first analysis method: statistical linear covariance analysis. This method combines the augmented state linear covariance framework with the statistical …

Aerodynamic Implications Of A Bio‐Inspired Rotating Empennage Design For Control Of A Fighter Aircraft, Christian R. Bolander

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This dissertation presents an analysis of the aerodynamics for an aircraft using a novel, bio-inspired control system. The control system is a rotating tail, that is inspired by the way in which birds use their tail to control their flight. An aerodynamic model for a baseline aircraft and a bio-inspired variant are created by referencing well-known relationships for the aerodynamics of flight, which are then used to analyze the available flight envelope at which each aircraft can reach two different equilibrium states. An analysis of the total aerodynamic control authority of each aircraft is also included along with a preliminary …

High Efficiency Angles-Only Space-Based Approaches For Geosynchronous Orbit Catalog Maintenance With Sparse Information, Louis M. Tonc

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The thesis of this dissertation proposes a novel filter algorithm to improve tracking and catalog maintenance of uncooperative satellites and other Resident Space Objects (RSOs) in Geosynchronous Equatorial Orbit (GEO). Tracking can be supported by space-based tracking from observer satellites (OBSs). Practical limitations can lead to long time gaps between measurement updates when tracking RSOs from an OBS, which may induce a loss of fidelity or divergence of the estimation algorithm. The Extended Kalman filter (EKF) is commonly used for tracking RSOs but it diverges as a consequence of nonlinearity in the dynamics and nonlinearity in the optical measurements from …

Understanding And Minimizing The Effects Of Propellant Mean Bulk Temperature Changes In Solid Rocket Motors, Thomas Sorensen

Student Research Symposium

Solid rocket propellant typically contains the geometry of an extruded annulus. This propellant, when ignited, burns radially at a rate called the “burn rate”. This rate dramatically affects important motor performance characteristics such as pressure, thrust, and specific impulse. Each different mixture of solid rocket propellant has a sensitivity to initial propellant temperature. The relationship between burn rate and initial temperature sensitivity function are each determined experimentally. This literature review will analyze existing experimental data. The objective of the research is to see if there is a reliable way to predict the burning rate’s temperature sensitivity prior to obtaining new …

Relating Throttled Hybrid Motor Performance To Oxidizer-To-Fuel Ratio, Trevor Coombs

Student Research Symposium

A hybrid rocket motor's ability to throttle and restart, along with other desirable traits, drives its potential to be an emerging technology in spaceflight applications. However, the current lack of an ability to maintain an optimal mixture ratio of oxidizer to fuel propellants, O/F ratio, during combustion limits the hybrid motor's overall efficiency. This study quantifies how variations in O/F ratio and combustion chamber pressure, which a throttle valve can indirectly manipulate upstream of the chamber, affect the characteristic velocity (c * ) and specific impulse (Isp) of the motor. The researcher uses an analytical hybrid rocket combustion model and …

New Rocket Fuel Blend For Hybrid Rocket Ignition Enhancement, Ryan Thibaudeau

Student Research Symposium

This work describes and compares different methods of ignition for hybrid rockets using acrylonitrile butadiene styrene (ABS) as the fuel and high-test hydrogen peroxide (HTP) as the oxidizer. Additionally, the work provides an overview of the current state of the art regarding ignition of HTP hybrid rockets. The approach to ignition methods using gaseous oxygen (GOX) pre-lead and catalytic ignition configurations are presented. The manufacturing process and testing results of a unique catalyst-infused fuel grain is presented as the optimal solution to overcome ignition latencies present in HTP-ABS hybrid rockets.

Controlling Oxidizer-Fuel Ratio With Vortex Injection In Hybrid Rockets, Max Francom

Student Research Symposium

Hybrid motors have existed as a hypothetical propulsion system for decades in a wide range of upper stage rocket motors due to their simple, robust, non-toxic, and versatile nature. However, inherent to hybrids is oxidizer:Fuel ratio (O:F Ratio) shift over time, the elimination of which would remove many potential barriers to hybrid rocket motor usage in most spaceflight applications. The most important and difficult part of analytical models of hybrid rockets is the regression/combustion rate of hybrid fuel. O:F Ratio control is fully dependent on the ability to manipulate this regression independently of Oxidizer mass input. One potential method of …

In-Situ Optical Measurements Of Combustion Plumes, Cara Frischkorn

Student Research Symposium

The exhaust plumes of rocket and jet propulsion systems feature highly-oxidizing, potentially corrosive, extremely high temperature flows. The hostility of these environments makes obtaining in-situ thermal flow measurements extremely difficult. The conventional method for these measurements uses Gardon heat-flux gauges requiring complex and highly invasive installations which cannot be used for flight applications. More recent work has used fiberoptic cable installations to sense internal flow conditions of hybrid and solid fuel rockets. In this configuration, fiber optic cables inserted through the fuel and into the flow are consumed by the flame as the fuel surfaces pyrolyze, but the cable tips …