Aerospace Engineering Commons^™

Attraction, Transport And Release Of Water Fleas’ Ephippia For Migration, Xiang Wang

Mechanical and Aerospace Engineering Dissertations - Archive

Planktonic crustaceans of the genus Daphnia live in aquatic environments. Although they are lack of walking and flying capabilities, they have developed adaptations that facilitate the dispersal of their dormant forms, ephippia to cross terrestrial barriers and reach neighborhood waterbodies. It increases the survival rate of their species. A possible way for this spread to occur is the transport of their ephippia through waterfowls’ legs. Yet, little is known about the key role of the legs in the dispersal and the main mechanisms. The ephippia first get attached to the waterfowls’ legs. The waterfowls may then carry these ephippia to …

Investigation Of The Impact Of Material Models On Reliability Assessment Of Electronic Packages, Abel Misrak

Mechanical and Aerospace Engineering Dissertations - Archive

Drop testing, thermal cycling, power cycling, etc. are some of the tests used to assess the reliability of new electronic products. However, performing experimental study of every new design is costly and time consuming. Computational tools are often employed to perform the required reliability analysis in a shorter time period and save valuable resources. Extensive set of material characterization work needs to be done before an accurate material model can be developed and used in computational analysis. Structural components such as printed circuit boards (PCBs) are critical in the thermomechanical reliability assessment of electronic packages. The bulk material properties of …

Sub-Modelling Approach For Computationally Efficient Thermal Simulations Of Large Li-Ion Battery Packs, Vishnu V. Ganesan

Mechanical and Aerospace Engineering Theses - Archive

Accurate and rapid prediction of temperature distribution in a large Li-ion battery pack comprising thousands of cells is critical for ensuring safety and performance of battery packs for electric vehicles (EVs). Due to the multiscale geometry and the large number of individual cells in an EV battery pack, full-scale thermal simulations typically take a long time to complete. Approaches for rapidly computing the temperature field in a large battery pack without significant loss of accuracy is, therefore, a key technological need. This paper presents thermal simulations of a large, air-cooled Li-ion battery pack containing thousands of individual cells using the …

Correlation And Effect Of Process Parameters On The Properties Of Inconel 718 Parts Fabricated By Selective Laser Melting Using Response Surface Method, Bharath Bhushan Ravichander

Mechanical and Aerospace Engineering Theses - Archive

Inconel 718 (i.e., IN718) is a nickel-based superalloy that exhibits outstanding tensile and impact-resistant properties, along with good high-temperature corrosion resistance. However, the machinability is poor due to the high stiffness of IN718. Therefore, additive manufacturing provides an effective solution to overcome the work hardening. Selective laser melting (SLM) is the most common powder-bed additive manufacturing technique designed to use a high power-density laser to melt and fuse the metallic powder to fabricate functional parts with high accuracy. However, the accuracy and the functional properties of the fabricated parts are greatly dependent on the process parameters. Thus, depending on the …

On The Effect Of Interfacial Patterns On Energy Dissipation In Plastically Deforming Adhesive Bonded Ductile Sheets, Arturo Pascuzzo, Arief Yudhanto, Marco Alfano, Gilles Lubineau

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Toughening of brittle adhesive joints is a topic of great interest for the fabrication of layered structures. Recent experimental work by the authors indicated that spatially varying interface properties (i.e., patterned interfaces obtained using laser irradiation) could tune energy dissipation in plastically deforming adhesive joints. In this study, we use a cohesive zone approach to ascertain the interplay between fracture process zone size and pattern geometry on the overall work of separation. The analysis is carried out in the context of the elasto-plastic peeling response of adhesive bonded ductile thin sheets. The mating surfaces of the adherents feature alternating strips …

Aeroacoustics Of Supersonic Jet Interacting With Solid Surfaces And Its Suppression, Seyyed Saman Salehian

Doctoral Dissertations and Master's Theses

The noise generated by supersonic jet is of primary interest in the high-speed flight. In several flight conditions jet exhaust of the propulsion system interacts with solid surfaces. For example, jet impingement on ground for a rocket lift-off, or interactions influenced by the integration of the engine with the airframe. Such complex applications require consideration of the role of acoustic-surface interactions on the noise generation of the jet and its radiation. Numerical analysis of supersonic jet noise involved in these scenarios is investigated by employing Hybrid Large Eddy Simulation – Unsteady Reynolds Averaged Simulation approach to model turbulence.

First, the …

Uas Model Identification And Simulation To Support In-Flight Testing Of Discrete Adaptive Fault-Tolerant Control Laws, Mansi Subhash Bakori

Doctoral Dissertations and Master's Theses

In mission-critical applications of unmanned and autonomous aerial systems(UAS), it is of significant importance to develop robust strategies for fault-tolerant systems that can countermeasure system degradation and consequently support the integration into the National Airspace (NAS). This thesis research illustrates the results of systems identification that is performed using DATCOM followed by the flight test data. This data is acquired from conducting an intensive flight testings program of a fixed-wing UAS to determine the state-space model of the aircraft. A discrete state-space system is reconstructed from these models to derive Auto-Regressive Moving-Average (ARMA) models used to design a Discrete Direct …

Residual-Based Multi-Filter Methodology For All-Source Fault Detection, Exclusion, And Performance Monitoring, Juan Jurado, John F. Raquet, Christine M. Schubert Kabban Air Force Institute Of Technology, Jonathon S. Gipson

Faculty Publications

All-source navigation has become increasingly relevant over the past decade with the development of viable alternative sensor technologies. However, as the number and type of sensors informing a system increases, so does the probability of corrupting the system with sensor modeling errors, signal interference, and undetected faults. Though the latter of these has been extensively researched, the majority of existing approaches have constrained faults to biases and designed algorithms centered around the assumption of simultaneously redundant, synchronous sensors with valid measurement models, none of which are guaranteed for all-source systems. As part of an overall all-source assured or resilient navigation …

Deep Learning For Remote Sensing Image Processing, Yan Lu

Computational Modeling & Simulation Engineering Theses & Dissertations

Remote sensing images have many applications such as ground object detection, environmental change monitoring, urban growth monitoring and natural disaster damage assessment. As of 2019, there were roughly 700 satellites listing “earth observation” as their primary application. Both spatial and temporal resolutions of satellite images have improved consistently in recent years and provided opportunities in resolving fine details on the Earth's surface. In the past decade, deep learning techniques have revolutionized many applications in the field of computer vision but have not fully been explored in remote sensing image processing. In this dissertation, several state-of-the-art deep learning models have been …

Mechanism Of Compaction With Wrinkle Formation During Automatic Stitching Of Dry Fabrics And The Size Effect Of Compression Molded Discontinuous Fiber-Reinforced Composites, Anibal Benjamin Beltran Laredo

Mechanical & Aerospace Engineering Theses & Dissertations

With an ever-increasing demand for composites, more ways of manufacturing them are becoming popular and widely used. Stitching of dry fabrics is an efficient method for improving delamination resistance. Discontinuous fiber reinforced composites can be used as a lightweight alternative material for metals through a process of compression molding, which allows for complex shape manufacturing while offering structural grade mechanical properties.

This study demonstrates how the stitching of dry fabrics can be adapted to more complex surfaces. The consequences of stitching of curvilinear surfaces can result in defect formation. Therefore, to understand the physical formation of possible defects, experimental characterization …

Analysis Of Body And Tail Of A Flapping Drone, Yuan Chai

Student Works (2020-2029)

The Micro Aerial Vehicle (MAV) is a kind of unmanned aerial vehicle with a small size, which has a unique performance that larger aircrafts do not have. MAV can fly in confined spaces and perform hover, forward flight, etc. The flapping wing micro aerial vehicle is one type of flight imitates the insects (birds), which can fly based on the flapping wing. Compared with fixed-wing aircraft, the flapping wing micro aerial vehicle (FWMAV) has a smaller volume, lighter weight, and higher flight efficiency. FWMAV can be largely used in military and civil applications. In this project, the flapping drone is …

Fluid Flow Analysis Of Low-Altitute Agricultural Uav Pesticide Spraying Device, Dan Han

Student Works (2020-2029)

The nozzle is an important part of the drone pesticide spraying device. The quality of the nozzle directly affects the atomization performance. Fan nozzles are widely used in the field of plant protection in agriculture, forestry, pest control, and weed removal. When using drones to spray pesticides, the spraying velocity, the spraying range of the pesticides, and the atomized particle size are all key factors that directly affect the efficiency of pesticide use. This paper uses SOLIDWORKS and ANSYS software to design and simulate. The boundary conditions are kept the same, and the influence of the nozzle's grooving angle (α), …

Beacon Aided Robotics For Martian Cave Mapping, Ryan Joseph Capozzi

Theses and Dissertations

At present, lava tubes on the Moon and Mars have been left wholly unexplored. There are many aspects of subterranean exploration that pose additional challenges over surface exploration, and one of these issues is in localization. This project seeks to expand upon the traditional communication beacon that is dropped behind a robotic operator in subterranean environments and make low cost and low power modifications to increase their functionality by making robot localization from these beacons possible. This has been tested with the use of LED beacons that could be easily added to current solutions and used for localization of the …

General Electric J85 Engine Flame Holder Tooling, Jacob Portugal

Theses and Dissertations

Larsen Motorsports competes in drag racing events all over the country using their jet power drag cars. These competitions are focused on getting the most performance out of the engine as possible by shaving weight off the vehicle and increasing the amount of power produced. One of the many factors in the amount of power produced by the car is the afterburner. Afterburners can increase thrust from ~3,000lb to ~5,000lb in a standard J85 engine. Due to this there is a good deal of attention paid to the efficiency and performance of the afterburner. The specific portion this thesis focused …

Application Of Neural Networks For Solving One Dimensional Inverse Heat Conduction Problems With Surface Ablation, Jian Zhang

Theses and Dissertations

Thermal protection systems (TPS) are critical for space vehicles to keep them safe against extensive aerothermal heating, particularly during the atmospheric entry. Ablative materials burn away gradually when subjected to extreme heat flux and therefore are considered as a practical option for TPS application. Measurement of TPS surface condition, particularly heat flux, is essential to reduce design margins and also improve active control strategies for damage avoidance. However, it is not possible to directly measure TPS surface heat flux, and alternative approaches must be utilized for this purpose. One method is to use temperature sensors at internal layers and solve …

Analysis Of One Way Valve Mechanism For Wings Of A Flapping Drone, Xinchen Deng

Student Works (2020-2029)

The flapping drone is one type of MAVs which is defined as a miniature unmanned aerial vehicle that is inspired by flying birds and insects. Flapping wings can make a perfect combination of thrust and lift by flapping up and down with full usage of unsteady air. The flapping drone has the advantages of high maneuverability and a special lift generation mechanism. Compared with rotary-wing or fixed-wing MAV, it is smaller, lighter, and has higher flight performance. It can quickly change the flight direction and flight speed by control the flapping frequency and it is the only flight mode that …

Investigations Of Air-Water Multiphase Flow In Tubes: Computational Fluid Dynamics, Wei Hong Goo

Student Works (2020-2029)

Mixing is a very crucial process in many industries, such as food processing industry, minerals processing industry, petrochemicals and refining industry, pulp and paper industry, polymer industry, pharmaceuticals industry and many more. There are different types of mixing, such as liquid-gas mixing, liquid-liquid mixing, solid-liquid mixing and many more. The definition of multiphase flow is the simultaneous flow of materials with multiple thermodynamic phases. A lot of process industries require multiphase flows during operation. Bubbly flow is defined as the flow of liquids that contains dispersed gas bubbles. One of the main applications of multiphases flows and bubbly flows is …

Low-Cost Reaction Wheel Design For Cubesat Applications, Nicholas J. Bonafede Jr.

Master's Theses

As science instruments on CubeSats become more sensitive to the attitude of the spacecraft, better methods must be employed to provide the accuracy needed to complete the planned mission. While systems that provide the accuracy required are available commercially, these solutions are not cost-effective, do not allow the design to be tailored to a specific mission, and most importantly, do not give students hand-on experience with attitude control actuators. This thesis documents the design, modeling, and simulation of a low-cost, student-fabricated, reaction wheel system for use in 3U CubeSat satellites. The entire design process for the development of this reaction …

Pathfinding Interplanetary Bus Capability For The Cal Poly Cubesat Laboratory Through The Development Of A Phobos-Deimos Mission Concept, Alyssa M. Ralph

Master's Theses

With the rise of CubeSats and the demonstration of their many space applications, there is interest in interplanetary CubeSats to act for example as scientific investigations or communications relays. In line with the increasing demand for this class of small satellites, the Cal Poly CubeSat Lab (CPCL) seeks to develop a bus that could support an interplanetary science payload. To facilitate this, a mission concept to conduct science of the moons of Mars, Phobos and Deimos, is investigated by determining the mission needs for a CubeSat in a Phobos-Deimos cycler orbit through the development of a baseline design to meet …

A General Approach To Lifting-Line Theory, Applied To Wings With Sweep, Jackson T. Reid

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Lifting-line theory is one simple method of predicting the lift produced by a wing. The traditional implementation of lifting-line theory, developed in 1918, is limited to predicting the lift of traditional straight wings. In this work, lifting-line theory is extended to predict the lift produced by modern swept (or "v-shaped") wings by strategically handling the singularities inherent to the theory. The resulting formulation is shown to be both accurate and computationally inexpensive, when compared to experimental and higher-fidelity computational results, demonstrating the method's usefulness as an aerodynamic design tool. Because of the low computational cost and accuracy of the method …