Engineering Commons^™

Single Axis Stability Autonomous Glider Control, Brian Study

Student Works

To investigate and increase knowledge on autonomous control systems, an autonomous glider was fitted with a control system with the purpose of creating a craft that would be capable of maintaining a wings level condition despite perturbations to the trim condition. The glider measures bank angle and roll rate information from an accelerometer and gyro, before it relays the data to an equipped microcontroller. Programmed on the microcontroller is a control law to take the input from the sensors and issue a command to a single servo that controls both ailerons, allowing for the vehicle to autonomously correct its bank …

Soot And Spectral Radiation Modeling For High-Pressure Turbulent Spray Flames, Sebastian Ferreyro Fernandez, C. Paul, A. Sircar, A. Imren, D. C. Haworth, Somesh Roy, Michael F. Modest

Mechanical Engineering Faculty Research and Publications

A transported probability density function (PDF) method and a photon Monte Carlo/line-by-line (PMC/LBL) spectral model are exercised to generate physical insight into soot processes and spectral radiation characteristics in transient high-pressure turbulent n-dodecane spray flames, under conditions that are relevant for compression-ignition piston engines. PDF model results are compared with experimental measurements and with results from a locally well-stirred reactor (WSR) model that neglects unresolved turbulent fluctuations in composition and temperature. Computed total soot mass and soot spatial distributions are highly sensitive to the modeling of unresolved turbulent fluctuations. To achieve reasonable agreement between model and experiment and to capture …

Integrated Free-Form Method For Aerostructural Optimization Of Wind Turbine Blades, Ryan Barrett, Andrew Ning

Faculty Publications

A typical approach to optimize wind turbine blades separates the airfoil shape design from the blade planform design. This approach is sequential, where the airfoils along the blade span are pre-selected or optimized and then held constant during the blade planform optimization. In contrast, integrated blade design optimizes the airfoils and the blade planform concurrently and thereby has the potential to reduce cost of energy (COE) more than sequential design. Nevertheless, sequential design is commonly performed because of the ease of precomputation, or the ability to compute the airfoil analyses prior to the blade optimization. This research compares two integrated …

The Professional Constructor, Full Issue, Volume 43, Number 01

The Professional Constructor

No abstract provided.

Sysml Output Interface And System-Level Requirement Analyzer For The Horizon Simulation Framework, Viren Kishor Patel

Master's Theses

Model-Based Systems Engineering in industry has been constantly increasing its presence within the aerospace industry. SysML is one such MBSE tool that shows complex system organization and relationships. The Horizon Simulation Framework is another MBSE tool, created by Cal Poly students, that gives users the ability to run “day-in-the-life” simulations of systems. Finding a way to link these two tools could allow systems engineers to reap the benefits of both.

This thesis investigates the background and design process involved with developing the code that can convert an output file generated in SysML, into a format specifically made for the Horizon …

Case Study On The Development Of Engineering Design Modification Projects For U.S. Nuclear Power Plants: A Knowledge Retention Tool In Support Of The Longevity And Resilience Of The Nuclear Power Industry, Pamela M. Torres-Jiménez

Engineering Management & Systems Engineering Theses & Dissertations

The nuclear power industry in the United States (U.S.) has gone through various changes throughout its history. Most recently, plans to grow the industry through the construction of new power plants have ceased. Because of this, the industry is at a period where the longevity and resilience of existing nuclear power plants are vital to its subsistence.

One of the ways existing nuclear power plants can assure longevity and resilience is by performing engineering design modifications efficiently and at a lower cost. Strategic plans, such as the Delivering the Nuclear Promise, can support nuclear utilities to achieve this. Another strategy …

Non-Invasive Picosecond Pulse System For Electrostimulation, Ross Aaron Petrella

Electrical & Computer Engineering Theses & Dissertations

Picosecond pulsed electric fields have been shown to have stimulatory effects, such as calcium influx, activation of action potential, and membrane depolarization, on biological cells. Because the pulse duration is so short, it has been hypothesized that the pulses permeate a cell and can directly affect intracellular cell structures by bypassing the shielding of the membrane. This provides an opportunity for studying new biophysics. Furthermore, radiating picosecond pulses can be efficiently done by a compact antenna because the antenna size is comparable to the pulse width. However, all of the previous bioelectric studies regarding picosecond pulses have been conducted in …

Predicting Effects Of Climate Change And Sea Level Rise On Hydrologic Processes In A Mid-Atlantic Coastal Watershed, Rui Li

Civil & Environmental Engineering Theses & Dissertations

This dissertation assessed impacts of Climate Change (CC) and Sea Level Rise (SLR) on coastal hydrologic processes using the Lynnhaven River watershed as a test bed. The watershed is part of Chesapeake Bay Watershed and hydraulically connected with mid-Atlantic Ocean. Six CC scenarios were considered in terms of eight Regional Climate Models’ predictions for three Intergovernmental Panel on Climate Change (IPCC) emission assumptions, namely, B1, A1B, and A2, for two future periods, namely 2046 to 2065 and 2081 to 2099. The ensemble means of downscaling results from four methods were used to represent the future climates. On the other hand, …

Idpal - Input Decoupled Partially Adiabatic Logic: Implementation And Examination, Kevin A. Johnson

Electrical & Computer Engineering Theses & Dissertations

This thesis presents the experimental results of a four-phase IDPAL eight-input exclusive-OR gate. The following problems with IDPAL are addressed: multistage circuits malfunctioning, simulation convergence anomalies, and inferring input information through the power clock current. EPAD MOSFETs, which provide a low threshold voltage, are shown to be unsuccessful in correcting the malfunctioning behavior of multilayer circuits. A solution to multilayer IDPAL circuits malfunctioning, called IDPAL with discharge, is shown. The differences between simulation waveforms produced by LTspice and the experimental circuits recorded by a Tektronix’s Oscilloscope are investigated. IDPAL is implemented and analyzed using ALD MOSFETs for the following adiabatic …

Improved Thermal Stability Of Cesium-Doped Perovskite Films With Pmma For Solar Cell Application, Christine M. Gausin

Electrical & Computer Engineering Theses & Dissertations

Perovskite solar cells (PSCs) have the potential to replace the traditional silicon solar cells for commercialization applications. Perovskites offer a lower cost to fabrication, superb efficiencies, high absorption coefficients, longer carrier lifetime and diffusion lengths. Despite their improved efficiency, perovskites suffer from several degradations relating to the material’s organic-inorganic composition upon exposure to different environmental conditions. In general, the main causes of degradation of perovskite films are due to exposure to moisture, oxygen, air, light, and temperature. Several efforts have been made to stabilize perovskites including encapsulation, doping of cations, and alterations to the perovskite structure. In this work, we …

Volterra Series Approximation For Multi-Degree Of Freedom, Multi-Input, Multi-Output, Aircraft Dynamics, Alexander J. Chen

Mechanical & Aerospace Engineering Theses & Dissertations

An analytical model of a second order system is extended from a single-axis framework, to a multi-axis, multi-degree of freedom framework for a multiple input, multiple output system. This mathematical model is built from the variational approach of the Volterra series representation of nonlinear systems. The new representation describes the second order, oscillatory natural modes of a system, and shows how to organize the Volterra terms in intuitive ways. The constructed mathematical model aims to establish an organization of the Volterra kernels to allow for analytical cause and effect type analysis on system behavior.

To demonstrate the accuracy of the …

Distributed Sensing And System Identification Of Cantilever Beams And Plates In The Presence Of Weak Nonlinearities, Patrick Sean Heaney

Mechanical & Aerospace Engineering Theses & Dissertations

While the mathematical foundation for modal analysis of continuous systems has long been established, flexible structures have become increasingly widespread and developing tools for understanding their mechanics has become increasingly important. Cantilever beams and plates, in particular, have been extensively studied due to their practical importance as approximations of more complex structures. The focus of this thesis is on understanding the dynamics of vibrating cantilever beams and plates through analytical and experimental investigation. Various models for the mechanics of these structures, of varying physical fidelity, are described and compared. A fiber optic sensing system is utilized to experimentally acquire distributed …

Investigation Of Microfluidic Kelvin Water Dropper And Its Applications In Contact And Contactless Electrowetting, Elias Yazdanshenas

Mechanical & Aerospace Engineering Theses & Dissertations

A typical Kelvin water dropper is a device that can convert gravitational potential energy to a high voltage electrostatic. This device consists of two inductors, two collectors, tubes, and electrical connections. A Kelvin water dropper is able to generate extremely high voltage by separating ions using two positive feedback loops. A Kelvin water dropper provides a low cost solution for the applications in which high voltage is needed. In the present research, low cost Microfluidic Kelvin Water Droppers (MKWDs) were developed and built in house for electrowetting applications. Two MKWDs with different tube inner diameters (254 and 508 μm) were …

Understanding The Mechanical Behavior Of Costal Cartilage At Their Curved Exterior Surface Via A Tactile Sensor With A Built-In Probe For Distributed-Deflection Detection, Jiayue Shen

Mechanical & Aerospace Engineering Theses & Dissertations

This dissertation is aimed to determine the mechanical properties at the exterior surface of costal cartilages (CC) and examine how they vary with the cartilage length and the anatomical sites of CC in the ribcage via conformal indentation testing which is built upon a tactile sensor for distributed-deflection detection. The sensor entails a rectangular Polydimethylsiloxane (PDMS) microstructure sensing-plate integrated with a 5 ×1 transducer array with 0.75mm spatial resolution underneath and a built-in probe of 0.5mm×5mm×3mm above. By pressing the sensor against the exterior surface of a CC tissue with a pre-defined indentation pattern, the sensor conforms to the curved …

Modeling Effects Of Rainwater Harvesting Systems On Water Yield Increase And Non-Beneficial Evaporation Reduction To Sustain Agriculture In A Water-Scarce Region Of China, Tennille Wade

Civil & Environmental Engineering Theses & Dissertations

The northwestern region of China, which has an arid/semiarid climate, relies heavily on agriculture to provide food for the growing population. Climate change is affecting water availability in the region, causing long periods of drought and water scarcity followed by shorter periods of heavy rainfall and excess water availability. The ridge and furrow rainwater harvesting systems (RFRWHS) are a means of solving the problem of water scarcity; the systems can replenish soil moisture, reduce non-beneficial evaporation from bare soils, and increase surface water yield. In such a region, the hydrologic cycle is dominated by soil evaporation, leading to minimal surface …

New Method Of Nickel Oxide As Hole Transport Layer And Characteristics Of Nickel Oxide Based Perovskite Solar Cell, Loi Nguyen

Electrical & Computer Engineering Theses & Dissertations

For perovskite solar cells, poly (2,3-dihydrothieno-1, 4-dioxin)-poly (styrenesulfonate) (PEDOT:PSS) is a common hole transport layer. However, PEDOT:PSS has a lot of drawbacks, such as irregular quality from distributors, poor electron blocker, and hygroscopic nature. On the other hand, NiOx has been reported that it can provide good stability and carrier mobility. From literature, NiOx was used to replace PEDOT:PSS as a hole transport layer with positive results since it is transparent as a thin film and also possesses compatible work function in perovskite solar cell bandgap alignment. In depositing NiOx as a thin film, many approaches have been developed. However, …

A Cost Effective Design For A Propeller Thrust/Torque Balance, Nicholas Barrett Sadowski

Mechanical & Aerospace Engineering Theses & Dissertations

Wind tunnel balances are used with aircraft models, propellers, and components to measure applied forces and moments. The design and manufacture of a balance is often for a specific test, test article and conditions. This paper discusses the theory, design, calibration, and testing of a new small propeller balance for use in a low-speed wind tunnel. The new balance is named the ODU15X15.

Theory discussed herein covers how the two measurement components, thrust and torque, affect the balance design. These loads generate strains which are in turn read by strain gages arranged in Wheatstone bridges. The design follows well known …

Accounting The Hydraulically Largest Cross-Section Earth Duct Design, K. Baymanov, U. Kdirbaev

Karakalpak Scientific Journal

In the article the methods of calculating rational form and sizes of cross sections of irrigation canals are viewed. This contributes to increasing the flow capacity of the stream for 10-20%, decreasing glistening of irrigation canals and caving the ground works during the construction of canals.

Pore-Scale Analysis Of Interfacial Instabilities And Impact Of Heterogeneity On Relative Permeability By Lattice Boltzmann Method, Zhipeng Zhu

LSU Master's Theses

Interfacial instabilities occur often during immiscible fluid flow through porous media and their understanding is essential for waterflooding operations or other oil recovery processes. Although many studies including experimental and numerical have been done to reproduce and analyze the interfacial instabilities in porous median, there is still significant knowledge gap in fundamental understanding of these flow instabilities at the pore-scale. In order to better understand the interfacial instabilities phenomenon, the pore-scale simulations are performed. In this study, Lattice Boltzmann Method is used to simulate two different types of interfacial instabilities: viscous fingering and capillary fingering in irregular sphere packs by …

Automated Man-In-The-Middle Attack Against Wi‑Fi Networks, Martin Vondráček, Jan Pluskal, Ondřej Ryšavý

Journal of Digital Forensics, Security and Law

Currently used wireless communication technologies suffer security weaknesses that can be exploited allowing to eavesdrop or to spoof network communication. In this paper, we present a practical tool that can automate the attack on wireless security. The developed package called wifimitm provides functionality for the automation of MitM attacks in the wireless environment. The package combines several existing tools and attack strategies to bypass the wireless security mechanisms, such as WEP, WPA, and WPS. The presented tool can be integrated into a solution for automated penetration testing. Also, a popularization of the fact that such attacks can be easily automated …

A Sketch-Based Rapid Modeling Method For Crime Scene Presentation, Pu Ren, Wuyang Shui, Jin Liu, Yachun Fan, Wenshuo Zhao, Mingquan Zhou

Journal of Digital Forensics, Security and Law

The reconstruction of crime scene plays an important role in digital forensic application. This article integrates computer graphics, sketch-based retrieval and virtual reality (VR) techniques to develop a low-cost and rapid 3D crime scene presentation approach, which can be used by investigators to analyze and simulate the criminal process. First, we constructed a collection of 3D models for indoor crime scenes using various popular techniques, including laser scanning, image-based modeling and geometric modeling. Second, to quickly obtain an object of interest from the 3D model database, a sketch-based retrieval method was proposed. Finally, a rapid modeling system that integrates our …

Experimental Investigation Of A New Spiral Wingtip, Naseeb Ahmed Siddiqui, Mohammed Aldheeb, Waqar Asrar, Erwin Sulaeman

International Journal of Aviation, Aeronautics, and Aerospace

Experiments on the relative merits and demerits of slotted wingtips mimicking a bird’s primary feathers have been performed. The real emargination length of feather tips, their flexibility and curved shapes during cruise are considered in the present study. The experiments were performed at a Reynolds number of 3.7 x 10⁵ on a symmetric flat plate half wing of aspect ratio 3. Lift, drag and pitching moments were measured using a six component aerodynamic balance. Four different shapes inspired by bird primary feathers have been analysed. The rigid curved tip performed the best increasing the L/D ratio by 20%. This …

Modeling And Validation Of Local Electrowinning Electrode Current Density Using Two Phase Flow And Nernst-Planck Equations, Joshua M. Werner, W. Zeng, M. L. Free, Z. Zhang, J. Cho

Mining Engineering Faculty Publications

In this work we demonstrate the validity of a multi-physics model using COMSOL to predict the local current density distribution at the cathode of a copper electrowinning test cell. Important developments utilizing Euler-Euler bubbly flow with coupled Nernst-Planck transport equations allow additional insights into deposit characteristics and topographies.

Highly Efficient Electrochemical Reforming Of Ch4/Co2 In A Solid Oxide Electrolyser, Jinhai Lu, Changli Zhu, Changchang Pan, Wenlie Lin, John P. Lemmon, Fanglin Chen, Chunsen Li, Kui Xie

Faculty Publications

Reforming CH₄ into syngas using CO₂ remains a fundamental challenge due to carbon deposition and nanocatalyst instability. We, for the first time, demonstrate highly efficient electrochemical reforming of CH₄/CO₂ to produce syngas in a solid oxide electrolyser with CO₂ electrolysis in the cathode and CH₄ oxidation in the anode. In situ exsolution of an anchored metal/oxide interface on perovskite electrode delivers remarkably enhanced coking resistance and catalyst stability. In situ Fourier transform infrared characterizations combined with first principle calculations disclose the interface activation of CO₂ at a transition state between a CO …

Simplified Approach For Structural Evaluation Of Flexible Pavements At The Network Level, Karthikeyan Loganathan

Civil Engineering Theses

Currently, there is no simple procedure available to identify structurally weak pavement sections using Falling Weight Deflectometer (FWD) data at the network level (e.g., city, state or province). A simple method is needed to determine the structural condition of pavement sections that can be directly implemented and automated in the current pavement databases. The method needs to be simple enough to be used with a network level FWD database for the purpose of numerically ranking pavement sections at the network level from good to poor. Backcalculation has been utilized to obtain layer moduli and determine overlay (new added surface pavement …

Power Spectrum Prediction Of Amplified Dual-Band Lte-Advanced Signals, Xianzhen Yang

Dissertations and Theses

In wireless communication, the nonlinearity of a radio frequency (RF) power amplifier is an important issue for power amplifier designers. Since the nonlinearity is generated by the properties of physical components, it is hard to avoid it in producing power amplifiers. Power amplifier designers should know about the nonlinearity in order to compensate for it.

A two-tone test is a relatively widely used method to measure the nonlinearity of a power amplifier, which means the third order intercept point (IP3) can be measured from the two-tone test. Through the two-tone test, researchers have proposed some formulae to present what the …

Nanosatellite Space Experiment, Robert J. Twiggs

Robert "Bob" Twiggs STEM Education Collection

A report written by Professor Bob Twiggs titled "Nanosatellite Space Experiment" from March 30, 2018.

In Situ Extrinsic Doping Of Cdte Thin Films For Photovoltaic Applications, Imran Suhrid Khan

USF Tampa Graduate Theses and Dissertations

The Cadmium Telluride thin film solar cell is one of the leading photovoltaic technologies. Efficiency improvements in the past decade made it a very attractive and practical source of renewable energy. Considering the theoretical limit, there is still room for improvement, especially the cell’s open circuit voltage (VOC). To improve VOC, the p-type carrier concentration and minority carrier lifetime of the CdTe absorber needs to be improved. Both these parameters are directly related to the point defect distribution of the semiconductor, which is a function of deposition stoichiometry, dopant incorporation and post-deposition treatments.

CdTe films were deposited by the Elemental …

Mash Test No. 3-10 Of A Non-Proprietary, High-Tension, Cable Median Barrier For Use In 6h:1v V-Ditch (Test No. Mwp-9), Mojdeh Asadollahi Pajouh, Karla A. Lechtenberg, Ronald K. Faller, James C. Holloway, Robert W. Bielenberg, Scott K. Rosenbaugh

Nebraska Department of Transportation: Research Reports

The Midwest Pooled Fund Program has been developing a prototype design for a non-proprietary, high-tension, cable median barrier for use in a 6H:1V median V-ditch. This system incorporates four evenly spaced cables, Midwest Weak Posts (MWPs) spaced at 8 to 16 ft (2.4 to 4.9 m) intervals, and a bolted, tabbed bracket to attach the cables to each post. Full-scale crash testing was needed to evaluate the barrier’s safety performance. According to the Manual for Assessing Safety Hardware 2016 (MASH) testing matrix for cable barriers installed within a 6H:1V median V-ditch, a series of eight full-scale crash tests are required …

Phase Ii Evaluation Of Floor Pan Tearing For Cable Barrier Systems, Dylan T. Meyer, Mojdeh Asadollahi Pajouh, Karla A. Lechtenberg, Ronald K. Faller, Robert W. Bielenberg, James C. Holloway

Nebraska Department of Transportation: Research Reports

The objective of this research effort was to mitigate the potential for floor pan tearing and penetration into the occupant compartment by modifying the posts utilized in a prototype cable barrier system. A series of dynamic component tests were conducted on the modified Midwest Weak Post (MWP). A bogie vehicle was equipped with a simulated floor pan designed to replicate the height, thickness, and strength of the floor pan of a Kia Rio. Two methods of post modification were investigated, including edge protection on the top of the MWP as well as weakening of the MWP at the ground line. …