Aerospace Engineering Commons^™

Experimental Study Of Progressive Crushing Behaviour In Pultruded E-Glass Tubes Using Crown Triggers And A New Perforated Trigger, Chirag Mohan Dodani

Theses and Dissertations

An experimental study is conducted on the progressive crushing behavior and the energy absorption during crushing of pultruded fiberglass tubes, initiated by two types of crush triggers, a previously tested crown trigger, and a new perforated trigger. These crush triggers are introduced at the loading end of a pultruded E-Glass/vinyl-ester, circular tube coupon. Coupons with various trigger diameters and number of holes are crushed under quasi-static compression, to evaluate the trigger effectiveness, crushing response, and energy absorption during sustained crushing. It is observed that all trigger types induced progressive crushing in the splaying mode, characterized by the formation of a …

Autonomous Feature Detection For Capture Path Planning For Rendezvous And Docking With Non-Cooperative Spacecraft, Trupti Mahendrakar

Theses and Dissertations

With the increasing risk of collisions with space debris and the growing interest in on-orbit servicing, the ability to autonomously capture non-cooperative, tumbling target objects remains an unresolved challenge. This thesis provides an autonomous and artificial intelligence solution to either inspect, avoid, or perform on-orbit spacecraft servicing of an uncooperative resident space object (RSO). The solution is built on the fundamentals of Convolutional Neural Networks (CNN), which is used to classify the four most targeted features of a spacecraft essential for docking and collision avoidance during rendezvous, such as solar panels, antennas, spacecraft bodies, and thrusters. The solution was then …

Helicopter Flight Energy Modeling And Scaling For Urban Air Mobility Applications, Nolan Gene Hopkins

Theses and Dissertations

The costs associated with conducting full-scale helicopter flight tests in terms of both time and money beg to question the validity of using small-scale model helicopters in order to predict full-scale performance. To do this, the energy change for a small time interval is determined throughout a full-scale helicopter’s flight of a given profile, and the overall energy use compared to model results. The profile is then scaled based on a variety of factors, and the accuracy of energy scaling compared for each. Scaling dimensions based off helicopter weight and energy reserve modeling show promising results, but comparison of relative …

Flight Test Evaluation Of Elevator Stick Force Gradients On General Aviation Aircraft, Isaac Lee Faust

Theses and Dissertations

The objective of this research is to establish a suitable method of changing elevator stick force gradients on a Piper Warrior II. After finding a range of stick force gradients, the gradients will later be evaluated to get handling qualities ratings. A stick force gradient is the change in stick force as the airspeed deviates from trim condition. An aircraft’s yoke force gives pilots haptic feedback which improves their situational awareness without the need to assess instrument readings. A high stick force gradient will give the pilots a lot of feedback but will require more physical exertion to fly the …

Post-Processing And Characterization Of Additive Manufactured Carbon Fiber Reinforced Semi-Crystalline Polymers, Patricia Revolinsky

Mechanical & Aerospace Engineering Theses & Dissertations

The aim of this work is to study the effect of post-processing on additive manufactured (AM) continuous carbon fiber reinforced plastics (CFRPs) performance. As-printed AM CFRPs do not perform as well as conventionally manufactured CFRPs with the same composition. Possible improvements to AM CFRP performance include annealing and applying uniaxial pressure with elevated temperature. Samples were subjected to pressure and temperature treatments and annealing at a constant temperature. Treated materials were subjected to three-point bending tests, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM) to characterize and assess sample performance. Results were assessed for flexural strength, …

Creep Behavior And Deformation Mechanisms Of Spark Plasma Sintered Oxide Ceramics For Aerospace Systems At 1300˚C - 1400˚C, David D. Swanson

Theses and Dissertations

The mechanical behavior of YAG and LuAG was investigated at elevated temperatures. The specific materials investigated in this work include high-purity, polycrystalline YAG, high-purity, polycrystalline LuAG, and two doped variants of YAG: 2at% Yb-doped, polycrystalline YAG and 2at% Er-doped, polycrystalline YAG. Several billets of each material were prepared and processed by means of spark plasma sintering (SPS). Many different sintering parameters were utilized in order to obtain materials with various physical properties and to identify the effects of sintering parameters on the average grain size of the resulting materials. The compressive creep behavior of these materials was investigated at 1300°C …

Space Domain Awareness Assessment Of Cislunar Periodic Orbits For Lagrange Point Surveillance, Adam P. Wilmer

Theses and Dissertations

Cislunar periodic orbits provide an elegant means to fill the observational capability gaps which are present in ground-based and/or near-Earth spaced-base sensors. This research involves theoretical analysis on the effectiveness of cislunar periodic orbits for Space Domain Awareness (SDA) mission architectures. Specifically, cislunar periodic orbits are analyzed, both individually and in constellations with one another, for their effectiveness at monitoring target satellites in Lyapunov and halo orbits about the Earth - Moon L1 and L2 Lagrange points. All orbits are created and modeled in the Circular Restricted Three-Body Problem (CR3BP), then subject to perturbations in both the Elliptical Restricted Three-Body …

The Effect Of Shot Dependency On Composite Materials Subject To Ballistic Testing, Clayton C. Hankins

Theses and Dissertations

Ballistic analysis was performed on four common composite armor materials: 3k standard modulus plain weave carbon fiber, 8HS satin weave S-glass fiber, plain weave Kevlar® KM2 600 Denier fiber, and Spectra Shield® 4232 ultra-high molecular weight polyethylene to determine shot dependency based upon shot-to-shot impact distance, degree of penetration from the initial impacts, and the delamination effects from the initial impact. The primary measure of ballistic performance was the projectile velocity which represents a 50% probability of penetration, V₅₀. This velocity was determined using a three-phase optimal design test method with an average of twelve shots per test. …

Investigation Of Mirror Satellite Concept To Augment Natural Lighting Conditions On Orbit, Daniel M. Dombrowski

Theses and Dissertations

A method of augmenting on-orbit lighting conditions for rendezvous and proximity operations through the novel use of solar reflectors is presented. Natural lighting conditions on-orbit pose extreme challenges to these already complex missions. This research summarizes and applies the historical basis of solar reflectors to the proximity operations issues encountered today. Building on this past research, a simulation has been created to test the efficacy of a solar reflector constellation in facilitating less complex servicing/inspection missions. Initial testing has shown promising results for low mass membrane mirrors in augmenting illumination conditions with particular benefit in the geosynchronous orbital regime. Through …

Injection Studies On A Small-Scale Rotating Detonation Engine With Improved Flow Control, Jonathan J. Wyatt

Theses and Dissertations

The Rotating Detonation Engine (RDE) has gained increasing attention in recent years for its potential advantages over typical deflagration combustion. A Micro-RDE design with an outer diameter of 28mm operating on Nitrous Oxide and Ethylene was recently developed, which stretched the limits of small-scale detonation engines. The testing on this rig has shown a stable one wave mode detonation with frequencies reaching 16.8 kHz. Key parameters that influence the detonation wave mode are cell size, fill height, and wave speed, which are heavily influence d by injection schemes. Previous testing utilized a partially premixed jets in crossflow (JIC) injection scheme, …

Optimal Sizing And Control Of Hybrid Rocket Vehicles, Srija Ryakam

Doctoral Dissertations and Master's Theses

In the present work, a genetic algorithm is used to optimize a hybrid rocket engine in order to minimize the propellant required for a specific mission. In a hybrid rocket engine, the mass flow rate of the oxidizer can be throttled to enhance the performance of the rocket. First, an analysis of the internal ballistics and the ascent trajectory has been carried out for different mass flow rates of the oxidizer as a function of time, for a fixed amount of oxidizer, in order to study the effect of throttling. Two equivalent problems are considered: in the first problem the …

Data-Driven Damage Initiation Criteria For Carbon Fiber Reinforced Polymer Composites, Alexander Richard Post

College of Computing and Digital Media Dissertations

Computational progressive failure analysis (PFA) is vital for the design, verification, and validation of carbon fiber reinforced polymer (CFRP) composites. However, the computational cost of PFA is usually high due to the complexity of the model. The damage initiation criterion is one of the essential components of a PFA code to determine the transition of a material’s state from pristine or microscopically damaged to macroscopically damaged. In this thesis, data-driven models are developed to determine the matrix damage initiation based on the Mohr-Coulomb model and Hashin model. For 2D plane stress states, the computational cost for determining damage initiation can …

Analysis Of Energy Utilization And Losses For Jet-Propelled Vehicles, Mohammad Abbas, David W. Riggins

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The global control volume-based energy utilization balance for an aerospace vehicle is extended to allow for the analysis of jet-propelled vehicles. The methodology is first developed for analyzing the energy utilization and entropy generation characteristics of jet engines without airframe considerations. This methodology, when combined with separate energy utilization analysis for an unpowered airframe, allows for the assessment of a powered vehicle. Wake entropy generation for a powered vehicle is shown to be the summation of the wake entropy generation associated with the propulsion system (no airframe) and the unpowered airframe. The fundamental relationship between overall entropy generation and the …

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 …

Graphene Flake Self-Assembly Enhancement Via Stretchable Platforms And External Mechanical Stimuli, Harrison A. Loh, Claudio Marchi, Luca Magagnin, Konstantinos A. Sierros

Faculty & Staff Scholarship

While the green production and application of 2D functional nanomaterials, such as graphene flakes, in films for stretchable and wearable technologies is a promising platform for advanced technologies, there are still challenges involved in the processing of the deposited material to improve properties such as electrical conductivity. In applications such as wearable biomedical and flexible energy devices, the widely used flexible and stretchable substrate materials are incompatible with high-temperature processing traditionally employed to improve the electrical properties, which necessitates alternative manufacturing approaches and new steps for enhancing the film functionality. We hypothesize that a mechanical stimulus, in the form of …

Investigations Of The Negative Temperature Coefficient Region Of Sustainable Aviation Fuels For Mitigation Of Global Warming, Richard C. Smith Iii

Honors College Theses

An investigation was led to determine the correlations between the durations of Ignition Delay (ID), Combustion Delay (CD), Derived Cetane Number (DCN), Negative Temperature Coefficient (NTC), Low-Temperature Heat Release (LTHR) regions, ringing intensity, and precent mass burn, and the effect of blending the Fischer-Tropsch (F-T) synthetic aerospace fuel (SAF), iso-paraffinic kerosene (IPK), with petroleum derived Jet-A aerospace fuel on these regions. Neat blends of Jet-A and IPK and three by mass blends of the fuels will be researched. These blends include mass percentages of 75%Jet-A and 25%IPK (75Jet-A25IPK), 50%Jet-A 50%IPK (50Jet-A50IPK), and 25%Jet-A 75%IPK (25Jet-A75IPK). The study will utilize a …

Fatigue Damage Quantification And Life Estimation With Provision For Microstructure, Arash Pourbagheri Jirandehi

LSU Doctoral Dissertations

This dissertation provides methodologies for the quantification of different forms of fatigue damage by considering the role of microstructure. The laws of thermodynamics in conjunction with Finite Element Method (FEM) are utilized to devise thermodynamically-base frameworks for the estimation of cyclic damage in polycrystalline metals. Accordingly, a microstructure-sensitive platform for fatigue life estimation is introduced. The proposed framework is assessed for 3D printed metallic alloys at room and elevated temperatures. Further, it is used to analyze the fatigue performance difference between additively manufactured Inconel 718 in three print orientations. This research is of fundamental vital interest because it ensures that …

Issue 18: Contributors, Don Flournoy

Online Journal of Space Communication

List of Issue 18 Contributors

Sunsat Design Competition 2015-2016 First Place Winner – Team Space Transport: Power Satellites Beamed Energy Bootstrapping, Keith Henson, Anna Nesterova

Online Journal of Space Communication

This International SunSat Design Competition first-place winner for 2016 describes a beamed energy transport system that will operate in Space above low earth orbit (LEO) as a way to move power satellite parts into high orbits.

This design, entitled “Beamed Energy Bootstrapping,” makes use of small propulsion power satellites to provide the energy for space-based vehicles using electric arcjets. The proposal lays out a scheme to get the first propulsion power satellite in place without damage as it passes through the orbiting space junk below 2000 km.

Click here to see the video: Space Transport for Power Satellites Beamed Energy …

Sunsat Design Competition 2015-2016 Second Place Winner – Team Pathway To Power : Wireless Power Transfer, Javier Tandazo, Ethan Wong, Curtis Waggoner, John Guggenheim, Alexander Carter

Online Journal of Space Communication

Solar Power Satellites (SPS) using Wireless Power Transfer (WPT) to beam renewable energy to consumers on earth face three grand challenges: moving parts, heat dissipation, and radio interference. Solutions to each of these “show stoppers” are presented here. Further, a progressively more-complex pathway is described which starts where we are now and leads step-wise to implementation of large-scale Space Solar Power (SSP).

The first two grand challenges are addressed by a novel SPS design based on a thin-walled cylinder configuration of solar panels. The remaining challenge is tackled through a newly-discovered antenna configuration which allows dramatic reduction in radio/telecom interference …

Sunsat Design Competition 2014-2015 Third Place Winner – Team Martian: Space Solar Power Test Bed, Jeremy Straub, Tristan Plante, Benjamin Kading, Alex Holland, Landon Klein, Jordan Forbord

Online Journal of Space Communication

We propose a four-stage plan to demonstrate the effectiveness and safety of Space Solar Power (SSP) for use on Earth. Our project goal is to achieve Technology Readiness Level (TRL) by means of: 1) a test mission in low Earth orbit using a small spacecraft; 2) that will support a manned mission to Mars; 3) that includes a bent pipe experiment (power supplied from Earth, to a spacecraft and back to Earth), and 4) to complete system deployment.

The primary impediment to SSP implementation is thought to be the acceptance of the system by those on Earth who may be …

Sunsat Design Competition 2014-2015 First Place Winner – Team Cast: Multi-Rotary Joints Sps, Xinbin Hou, Meng Li, Lili Niu, Lu Zhou, Ying Chen, Zhengai Cheng, Haipeng Ji

Online Journal of Space Communication

Space Power Satellite (SPS) is a huge spacecraft designed to collect solar energy in space for supplying electric power to the electric grid on the ground. The SPS concept was first proposed by Dr. Peter Glaser in 1968.

Various studies on SPS in various countries have been produced over the past forty years. Today, there are multiple variations on this early concept, both in innovation and in optimization. Because of the huge size, immense mass and high power of these SPS installations, there are many technological difficulties.

Here, a new Multi-Rotary Joints SPS (MR-SPS) concept is proposed. The large solar …

Sunsat Design Competition 2014-2015 Second Place Winner – Team Sunflower: Thermal Power Satellite, Keith Henson, Steve Nixon, Kris Holland, Anna Nesterova

Online Journal of Space Communication

Space-based Solar Power has failed to be competitive on cost in spite of decades of study. A new approach appears to resolve the cost issue, undercutting coal and opening huge markets for low cost solar power from space. There are two parts to the problem. First is the cost of lifting parts to Geosynchronous Earth Orbit (GEO; second is the mass of parts that make up a power satellite.

Our team is proposing a combination that makes use of Skylon to Low Earth Orbit (LEO), and a 15,000 ton payload ground powered electric propulsion from LEO to GEO. This strategy …

Sunsat Design Competition 2013-2014 Third Place Winner – Team University Of North Dakota: Nano Ssp Satellite, Corey Bergsrud, Robert Bernaciak, Ben Kading, John Mcclure, Jeremy Straub, Subin Shahukhal, Karl Williams

Online Journal of Space Communication

This work presents the conceptualization of a Space-to-Space Microwave Wireless Power Transmission (S2S-MWPT) experimental demonstration mission using small spacecraft. Literature reviews [1, 2] suggest a stepwise procedure for technology demonstrations in support of advancing space solar power satellite (SSPS) systems. These technologies should be verified first on Earth and then in-space using small satellites. This project built its S2S-MWPT demonstration concept within the University NanoSat program restrictions (dimensions of 50cm x 50cm x 60cm and mass of 50kg). The idea is to use these upper limit restrictions to develop the MWPT spacecraft (MicroSat). Contained inside the MicroSat …

Sunsat Design Competition 2013-2014 Second Place Winner – Team Solar Maximum Llc: Sun-Synchronous Orbits, Danny R. Jones, Anna Nesterova

Online Journal of Space Communication

The orbital location of PowerSats plays a critical role in determining the mass of the solar power satellite (PowerSat) transmitter and the size of the rectenna on the Earth’s surface. These in turn play an important role in the cost of deploying the PowerSat, especially the cost of launching the PowerSat into orbit as the transmitter makes up a large part of the PowerSats mass. We will consider a new approach to PowerSat orbital positioning by considering a circular sun-synchronous orbit at 5,185.3 kilometers with an inclination of 142.1 degrees. Locating the PowerSat at this location offers several benefits and …

Sunsat Design Competition 2013-2014 First Place Winner – Team Rajiv Gandhi University: Helioastra, Akhil Raj Kumar Kalapala, Krishna Bhavana Sivaraju

Online Journal of Space Communication

HelioAstra is a creative design and visualization of an advanced Space Solar Power system. Its concept is validated by a credible science and engineering approach and an innovative business plan.

The space and ground receiving segments are made up of high efficiency Fresnel lens concentrator quantum dot solar cells. The solar array in space is sized at 933 m2. It delivers 1 MW (1000 kW) of perennial, clean and eco-friendly solar electric power at the bus-bars on the ground.

A solid state laser system containing Neodymium doped Yttrium Aluminium garnet (Nd: Y3Al5O12) will accurately and efficiently transmit power. A ground …

Traffic Collision Avoidance System: False Injection Viability, John Hannah, Robert F. Mills, Richard Dill, Douglas D. Hodson

Faculty Publications

Safety is a simple concept but an abstract task, specifically with aircraft. One critical safety system, the Traffic Collision Avoidance System II (TCAS), protects against mid-air collisions by predicting the course of other aircraft, determining the possibility of collision, and issuing a resolution advisory for avoidance. Previous research to identify vulnerabilities associated with TCAS’s communication processes discovered that a false injection attack presents the most comprehensive risk to veritable trust in TCAS, allowing for a mid-air collision. This research explores the viability of successfully executing a false injection attack against a target aircraft, triggering a resolution advisory. Monetary constraints precluded …

Wave Energy A New Energy Mix To Produce Green Hydrogen : A Potential Future Maritime Shipping Fuel : A Study On The Port Of Ngqura, Southern Africa's "Green Status Port", Zimasa Ntombemveli Macingwane

World Maritime University Dissertations

No abstract provided.

Issue 17: Contributors, Don Flournoy

Online Journal of Space Communication

List of Issue 17 Contributors

A Us-India Power Exchange Towards A Space Power Grid, Brendan Dessanti, Nicholas Picon, Carlos Rios, Shaan Shah, Narayanan Komerath

Online Journal of Space Communication

The Space Power Grid (SPG) architecture
described in papers from our group since 2006, is an
evolutionary approach to realizing the global dream of
Space Solar Power (SSP). SPG first concentrates on helping
terrestrial power plants become viable, aligning with public
policy priorities. It enables a real -time power exchange
through Space to help locate new plants at ideal but remote
sites, smooth supply fluctuations, reach high-valued
markets, and achieve baseload status. With retail cost kept
to moderate levels, a constellation grows in 17 years to 100
power relay satellites at 2000 km sun-synchronous and
equatorial orbits and 250 terrestrial …