Aerospace Engineering Commons^™

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 …

Sensor Module Network For Monitoring Trace Gases In The International Space Station, Aaron Beck, Drake Provost, Christopher English, Kamrin Gustave

Honors Capstones

The Jet Propulsion Laboratory (JPL) of the National Aeronautics and Space Administration (NASA) aims to develop a sensor network for the International Space Station (ISS) to ensure a comprehensive understanding of air quality within the station. The accumulation of carbon dioxide (CO­­­­­₂) can lead to cognitive impairment, headaches, and potentially dangerous situations at high concentrations. Monitoring air content at the ISS is critical to maintaining a healthy environment for crew onboard. Exposure to harmful gases causes negative side effects that make crew sick, which may interfere with their responsibilities. CO₂ is a gas that should be monitored …

Enhancing Microstructure, Composition Homogeneity, And Mechanical Properties In Laser Powder Bed Fused Metallic Alloys: Design, Fabrication, And Evaluation, Bahzad Farhang

Mechanical and Aerospace Engineering Dissertations - Archive

ABSTRACT: Over the past five decades, Nickel-based and Titanium-based alloys have become increasingly popular materials. As the manufacturing industry for these alloys has advanced, the demand for fabricating complex parts with enhanced mechanical properties at elevated temperatures has grown. Laser Powder Bed Fusion (LPBF), one of the most prevalent additive manufacturing techniques, has been employed successfully to produce these alloys. Nonetheless, there is still considerable effort being made to improve the microstructural, compositional, and mechanical properties of LPBF-processed components. In this study, we focused on adjusting the multi-scale microstructure and composition of LPBF-fabricated Nickel-based and Titanium-based alloys. The first objective …

Theoretical And Numerical Analysis Of Thermal Runaway Propagation In Li-Ion Battery Packs, Dhananjay Mishra

Mechanical and Aerospace Engineering Dissertations - Archive

Strategies to prevent or minimize propagation of thermal runaway in a pack of Li-ion cells are critically needed to ensure safe operation, storage and transportation. While significant literature already exists on thermal runaway simulations, several key questions of practical relevance have remained unaddressed. This work presents multi-mode heat transfer simulations to predict the onset and propagation of thermal runaway in a pack of cylindrical Li-ion cells. The impact of inter-cell gap and thermal properties of the interstitial material on onset and propagation of thermal runaway is studied. It is shown that high interstitial thermal conductivity promotes thermal runaway propagation. However, …

Steady State And Transient Analysis Of Heat Transfer In A Porous Fin With Radially Outwards Pressure-Driven Flow, Muhammad Mehdi Abbas

Mechanical and Aerospace Engineering Theses - Archive

Thermal management and energy storage problems often utilize extended surfaces, also known as fins for enhanced heat transfer. Today fins are used in a wide range of devices including but not limited to microelectronic components and large heat exchanger. Traditional fins as well as porous fins with flow orthogonal to fin direction have been subject of past research. There is very few academic literature available on porous fins with pressure driven flow along fin direction. While thermal conduction is usually the dominant mode of heat transfer in a solid fin, the use of porous fins that include advective thermal transport …

Development Of Vortex Box (Vbox) And Vortex Tip (Vtip) Filament Free-Wake Rotor Models, Casey Will Matsler

Mechanical and Aerospace Engineering Theses - Archive

Rotor models span from simple static and first order expressions to high fidelity, numerical computations and across the spectrum each model is good for different purposes. The use of models has improved with time and technological capability but choosing the right model for the task is important. A survey of rotor models is performed to identify a rotor model flexible enough for providing high to moderately high-fidelity results without significantly sacrificing computational time. The model chosen is intended to be for general purposes and applicable across a wide range of operating conditions. From the survey, a blade element rotor model …

Evaluation Of Solder Alloys For Bga Package: A Comparative Reliability Study Using Ansys Computational Analysis, Yashvanth Muthegowda

Mechanical and Aerospace Engineering Theses - Archive

Temperature cycling failure of solder joints in Ball Grid Array (BGA) packages has become a critical issue in electronic manufacturing. This thesis specifically characterizes three different lead-free solder alloys (Pure Indium, SAC-387, and SAC-Q) in BGA solder joints using two different printed circuit board (PCB) thicknesses (1mm and 0.7 mm). The analysis considers the non-uniform temperature distribution caused by the main heat source, the die, and the resulting deformation of the package due to the mismatch in the coefficient of thermal expansion (CTE) between components used in BGA. Finite element (FE) models are created in ANSYS mechanical package environment to …

Advancement Of An Inhouse Aerospace Vehicle Design Synthesis System Through The Introduction Of A Novel Database-Knowledgebase System And By Improving The Geometry And Aerothermodynamic Disciplinary Processes, Samuel Atchison

Mechanical and Aerospace Engineering Theses - Archive

Throughout the years of aerospace vehicle design, the process in which a vehicle is designed has drastically improved from being primarily developed through trial and error, to using sophisticated synthesis systems. While the trial-and-error process had its uses with providing the fundamental knowledge of how aircraft behave and can be designed, the increase in knowledge and technology allowed the possibility of more vehicle configurations to be explored without the need to build each one. This increase should have led to a revolution of vehicle designs, and while there have been some novel ones, it seems that the general design of …

Numerical Modeling Of Damper Configuration And Arrangements For Analysing Thermal Stratification In Modular Air Handling Units, Rohit Antony Raymonds

Mechanical and Aerospace Engineering Theses - Archive

Although air handling units are well established and maturated there are opportunities to optimize and improve the overall thermal and flow performance to reduce the carbon footprint of an air-cooled data center. Airside economization (ASE) arrangement to use cold outdoor air to minimize mechanical cooling energy was substantial progress in minimizing the power usage effectiveness (PUE) for data centers. ASE is an arrangement of ducts and dampers with the necessary controls to meet the cooling requirements. Dampers play a significant role in regulating the mass flow rate of the air and in mixing the two air streams: cold outdoor air, …

Effects Of Metal Organic Frameworks In Polyether Block Amide Elastomer, Joe Alex

Mechanical and Aerospace Engineering Theses - Archive

Metal-organic frameworks (MOFs) are highly porous materials that find extensive applications in gas absorption and separation in recent years. These hybrid materials can be designed with specific pore sizes and voids to selectively filter gases. PEBAX (MV 1074) is a commercially available polyether block amide copolymer generally used in gas separation applications. In this study, we characterize two different MOFs by means of a dispersion study and create a medium for them to be evenly dispersed into the aforementioned copolymer matrix. Polymer composite fibers are extruded using a twin-screw extruder and a winding unit at pre-determined parameters for winding speed …

Impact Of Immersion Cooling On Thermo-Mechanical Properties Of Non-Halogenated Core, Mohan Sai Ramalingam

Mechanical and Aerospace Engineering Theses - Archive

The rise in demand for modern high-power systems, which require fast processing and frequent data storage, has resulted in an exceptional and unprecedented increase in power density and heat generation within data centers. This eventually led to the need for advanced cooling techniques that can address the challenges of managing the heat produced by the data centers. As per Moore's law and Dennard's scaling, the power densities of chips and the heat flux generated by servers are continuously increasing. [1] As a result, the dissipation of heat at the chip level has also increased, posing a significant challenge for thermal …

Compliant Robot Manipulator For Transurethral Diagnosis, Samson A. Adejokun

Mechanical and Aerospace Engineering Dissertations - Archive

ABSTRACT: Minimally invasive procedures employ continuum manipulators, however, the internal human anatomy presents challenges relating to size, dexterity, and workspace for these manipulators. This research presents modeling, kinematic analysis, limited prototyping, and characterization of a micro-robotic manipulator to assess viscoelastic tissue properties of the bladder through transurethral palpation towards the diagnosis of bladder dysfunction, urinary incontinence, and early-stage bladder cancer. The proposed micro-robot consists of two subsystems; a unique 4mm outer diameter tendon-driven continuum segment from assembled “vertebrae” components with male and female snap-in features for joint assembly, an elastic tube encompassing each joint for controlled compliance and structural integrity …

Development Of Femtosecond Laser Electronic Excitation Tagging (Fleet) And Femtosecond Two-Photon Absorption Laser Induced Fluorescence (Fs-Talif) Diagnostics For Species Number Density And Velocity Measurements In Arc-Jet Flows, Daniel William Palmquist

Mechanical and Aerospace Engineering Dissertations - Archive

ABSTRACT: Arc-jet flows are the only ground-test facilities that can recreate hypersonic high-enthalpy flight conditions for long durations. Characterizing these complex flow regimes, generally under thermo-chemical non-equilibrium, is crucial to establishing a relationship between the ground-test environment and flight conditions. This work presents the development of two innovative and world’s first successful application of advanced non-intrusive laser-based diagnostic techniques for characterizing the 1.6 MW ONR-UTA Arc-Heated Wind Tunnel, Leste’s plasma flow. The arc-jet flow represents a unique challenge for the application of laser-based diagnostics due to the highly emitting background across a wide spectral range. Femtosecond Laser Electronic Excitation Tagging …

Fatigue Performance Modeling In Advanced Out-Of-Autoclave Composites For Aerospace Applications, Grayson Reid Curry

Mechanical and Aerospace Engineering Theses - Archive

Increased application of composite materials in the military and civil applications renewed the interest to development of high-fidelity methodologies for predicting their performance characteristics. Besides the traditional autoclave processed structural composites such as IM7/8552 and IM7/977-3 widely used on various platforms, novel materials such IM7/5320-1 suitable for Out-of-Autoclave (OoA) cure became of interest. Static and fatigue performance prediction of Open-Hole quasi-isotropic laminates made from IM7/5320-1 was performed in this work by using the Finite Element Analysis software BSAM. Progressive failure simulation including delaminations, matrix cracks and fiber failure was performed. Regularized eXtended Finite Element Methods (RXFEM) was used for mesh …

Design And Implementation Of High-Efficiency, Lightweight, System-Friendly Solid-State Circuit Breaker, Dehao Qin

All Dissertations

Direct current (DC) distribution system has shown potential over the alternative current (AC) distribution system in some application scenarios, e.g., electrified transportation, renewable energy, data center, etc. Because of the fast response speed, DC solid-state circuit breaker (SSCB) becomes a promising technology for the future power electronics intensive DC energy system with fault-tolerant capability. First, a thorough literature survey is performed to review the DC-SSCB technology. The key components for DC-SSCB, including power semiconductors, topologies, energy absorption units, and fault detection circuits, are studied. It is observed that the prior studies mainly focus on the basic interruption capability of the …

Innovation For The Air: A Brief History Of Worldwide Aviation, Lauren Plumley

Honors Program: Senior Projects (Public)

The purpose of this report is to present a brief but comprehensive overview of the variety of innovations related to aviation, and to discuss their impact on scientific progress over the course of human history. Relevant discoveries from the fields of physics and aerodynamics, and the numerous technologies built based upon these discoveries, are discussed over a period ranging from ancient times to the twenty-first century. The scope of this report is an overview of the development of powered and unpowered aircraft, including lighter-than-air, heavier-than-air, and aerospace technologies. Aviation developments were generally not limited to one specific country or person, …

Mechanical And Thermal Performance Of Additively Manufactured Digital Materials, Layth Muayyad Ahmad

Mechanical and Aerospace Engineering Theses - Archive

Over the past decades, additive manufacturing has become a critical material processing tool. All ranges of materials including polymers, composites, metals, and ceramics can be used to fabricate structures with complex geometries that are nearly impossible to build using conventional fabrication process. Recently, additive manufacturing methods to build polymeric structures have been advanced significantly. In particular, the emergence of multi-material printers has made it possible to seamlessly print hybrid and digital materials where materials components and compositions are digitally varied to construct fully tailored material system. In this work, using a commercially available polyjet printer (Stratasys J850 Prime 3D printer), …

Parametric Multi-Objective Optimization Of Cold Plate For Single-Phase Immersion Cooling, Geevarghese Joseph Nattasseriedathil

Mechanical and Aerospace Engineering Theses - Archive

The increasing demand for high performance computing in applications such as Internet of Things, Deep Learning, Big data for crypto-mining, virtual reality, healthcare research on genomic sequencing, cancer treatment etc. has led to the growth of hyper scale datacenters. To meet the cooling energy demands of HPC datacenters efficient cooling technologies must be adopted. Traditional air cooling, direct to chip liquid cooling and immersion are some of those methods. Among all, Liquid cooling is superior compared to various air-cooling methods in terms of energy consumption. Direct on-chip cooling using cold plate technology is one such method used in removing heat …

Investigation Of Dynamic Hybrid Rans-Les Turbulence Modeling For Cfd Simulation Of A Normal Jet In Crossflow, Cole Simmonds

Mechanical Engineering Undergraduate Honors Theses

The jet in crossflow is a canonical flow feature in many natural and engineered systems, ranging from pollutant dispersal in exhaust discharge to film cooling of high-temperature components in modern propulsion systems. The ability to computationally predict the flow features of jets in crossflow accurately and efficiently is therefore important for analysis and design for a wide variety of applications. In this study the capabilities of the dynamic hybrid RANS-LES (DHRL) turbulence modeling technique are investigated and compared to an industry standard Reynolds-averaged Navier-Stokes model (k-omega SST) in order to quantify the accuracy and computational cost of the two approaches. …

Simulating Dielectric Barrier Plasma Actuators With Varying Geometries, Cass Wiederkehr

Mechanical Engineering Undergraduate Honors Theses

The idea of Ionic Wind Propulsion has long been a topic of research for whether or not it can be used as a practical power source for flight. MIT researchers proved in 2018 that a plane with zero moving parts powered by Ionic Wind Propulsion was possible, and sustained flight could work with an internal power supply. However, due to the thin wire electrodes required to generate the ion cloud that made such propulsion possible, large amounts of drag rendered the plane extremely inefficient and impractical. Dielectric Barrier Discharge Devices (DBDs) are being investigated as to whether they can serve …

A Systematic Study Into The Design And Utilization Of Burn Wire As A Means Of Tensioning And Releasing Spacecraft Mechanisms Through Applied Joule Heating, Chandler Dye

Mechanical Engineering Undergraduate Honors Theses

The joule heating characteristics of Nichrome burn wires, often used as a thermal cutting device in mechanisms designed to fasten and release CubeSat deployables, are examined in the following thesis. Wires ranging from 0.125 inches to 2 inches long, and diameters of 30 Ga and 40 Ga, are investigated through analytical calculations and thermal simulations based on heat transfer due to joule heating, and through physical circuitry-based experiments. The temperature data is used to generate heating curves to predict the time it takes for Nichrome wires to fail under varying testing parameters. This research aims to catalog a series of …

Sealion Cubesat Mission Architecture Using Model Based Systems Engineering With A Docs As Code Approach, Kevin Yi-Tzu Chiu

Mechanical & Aerospace Engineering Theses & Dissertations

CubeSats are a growing population within the space industry. Every year, universities launch numerous amounts of CubeSats due to their inexpensive cost of development, launch, and deployment. However, this comes with numerous challenges. As the number of university-CubeSats grow, so too do the numbers that fail. With development teams consisting mainly of students with little to no training, proper and yet easy to use tools or methods should be implemented to help ensure mission success. Especially in the critical stages of planning before and during development, a technical approach to quickly track life cycle development of a CubeSat is needed. …

2023 Spring Graduate Recognition Program, Propulsion Research Center, Robert Frederick

PRC Graduate Recognition

This program includes the graduate recognition program for spring 2023. Includes photographs, upcoming events, recent publications, and student profiles.

Accident Investigation On In-Flight Loss Of Control Due To Configuration Change On Piper Arrow, Basilio Caruso

Theses and Dissertations

Between 2012 and 2021, NTSB has identified over 2200 accidents due to loss of control. The majority of which happened while flying in the pattern. The most challenging phase of a flight is the take-off and landing. During these phases, the pilot initiates a change of configuration of the airplane by lowering or retracting the flaps. Lowering the flaps slows down the plane and increases the lift of the wing but also changes the longitudinal free response of the aircraft. The pitch changes of the plane require the pilot to promptly compensate to keep straight and level flight and avoid …

Flight Test Evaluation Of The B-1b Lancer For The Heavy Bomber Mission, Robert William Gates

Theses and Dissertations

Copyright held by author

Smartphone Video Guidance Sensor In High-Altitude Uav Precision Landing, Joao Leonardo Silva Cotta

Theses and Dissertations

The Smartphone Video Guidance Sensor (SVGS) is an emerging technology developed by NASA Marshall Space Flight Center that uses a vision-based approach to accurately estimate the six-state position and orientation vectors of an illuminated target of known dimensions with respect to a coordinate frame fixed to the camera. SVGS is a software-based sensor that can be deployed using a host platform’s resources (CPU and camera) for proximity operations and formation flight of drones or spacecraft. The SVGS output is calculated based on photogrammetric analysis of the light blobs in each image; its accuracy in linear and angular motion at different …

Classification Of Electrical Current Used In Electroplastic Forming, Tyler Grimm

All Dissertations

Electrically assisted manufacturing (EAM) is the direct application of an electric current to a workpiece during manufacturing. This advanced manufacturing process has been shown to produce anomalous effects which extend beyond the current state of modeling of thermal influences. These purported non-thermal effects have collectively been termed electroplastic effects (EPEs).

While there is a distinct difference in results between steady-state (ideal DC) testing and pulsed current testing, the very definition of these two EAM methods has not been well established. A "long" pulse may be considered DC current; a "short" pulse may produce electroplastic effects; and even "steady-state" current shapes …

Multifunctional Additive Manufacturing And Multiphysics Numerical Investigations Of Carbon Fiber Structural Battery Composite Using A Drop-On-Demand Method With In-Situ Consolidation, Xiangyang Dong, Yuekun Chen

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Lightweight Carbon Fiber Structural Battery Composite Has Great Potential in Increasing Structural Energy Storage Efficiency for Multifunctional Applications. However, It is Still Challenging to Design Carbon Fiber Multifunctional Composite Due to Lack of Proper Manufacturing Methods. in This Study, an Integrated Multifunctional Design and Fabrication Approach is Developed by Combining a Drop-On-Demand Additive Manufacturing Method with a Multiphysics Numerical Model to Guide the Development of the New Multifunctional Composite. through Deposition with In-Situ Consolidation, the Function and Thickness of Each Carbon Fiber Layer as Well as its Fiber Volume Fraction Are Accurately Controlled. Decreasing Layer Thickness Improves Flexural Properties. the …

Heat Transfer In Microchannel Compact Heat Exchanger, Mohammed Al-Khateri

Theses

This study aims to investigate heat transfer in a miniaturized channel heat exchanger and effectiveness for given real-life design. The main objective of the study is to develop and build a high-performance heat exchanger for thermal management in automotive application using typical radiator manufacturing techniques. This research uses experimental and model-based investigation. It conceptualizes the Miniaturized Channel Heat Exchangers (MCHX) model-based study for demonstrating the design of miniaturized channel heat exchangers, manufacture, and study the heat exchanger effectiveness by validating the developed mathematical model experimentally. The proposed design of the MCHX is to use extruded tubes containing miniaturized channels as …

Mathematical Modeling: Finite Element Analysis And Computations Arising In Fluid Dynamics And Biological Applications, Jorge Reyes

UNLV Theses, Dissertations, Professional Papers, and Capstones

It is often the case when attempting to capture real word phenomena that the resulting mathematical model is too difficult and even not feasible to be solved analytically. As a result, a computational approach is required and there exists many different methods to numerically solve models described by systems of partial differential equations. The Finite Element Method is one of them and it was pursued herein.This dissertation focuses on the finite element analysis and corresponding numerical computations of several different models. The first part consists of a study on two different fluid flow models: the main governing model of fluid …