Engineering Commons^™

Fiber-Optic Imaging In An Internal Combustion Engine Test Rig, Conor Martin, Michael Smyser, Aswin Ramesh, Greg Shaver, Terrence Meyer

The Summer Undergraduate Research Fellowship (SURF) Symposium

The formation of particulate matter (PM/soot), nitrogen oxides (NOx), and other byproducts of the combustion process in diesel engines is controlled by spatiotemporally varying quantities within the engine cylinders which traditional sensors cannot resolve. This study explores the use of an advanced sensing technique using an optical probe which can be used to produce highly spatiotemporally resolved in cylinder images of the flame formation during the combustion stroke. Using a fiber optic cable and custom lensing system adapted to fit a pre-existing pressure transducer port, light from within the cylinder can be transmitted through the imaging probe to a high …

High Strain Rate Experiments Of Energetic Material Binder, Roberto Rangel Mendoza, Michael Harr, Weinong Chen

The Summer Undergraduate Research Fellowship (SURF) Symposium

Energetic materials, in particular HMX, is widely used in many applications as polymer bonded explosives (PBX) and rocket propellant. However, when damaged, HMX is known to be an unstable substance which renders it a hazardous material and in some cases unreliable. Finding critical mechanical conditions at high rates that render various forms of energetic materials as unreliable would be vital to understand the effects that vibrations and compression forces have on energetic materials. A better understanding would enable the ability to develop improvements in the manufacturing of PBX and rocker propellant. The method utilized to evaluate the mechanical properties of …

Development Of A Diode-Laser Absorption-Spectroscopy Sensor For Real-Time Control Of Combustion Systems, Rahul P. Balla, Christopher S. Goldenstein

The Summer Undergraduate Research Fellowship (SURF) Symposium

Tunable diode-laser absorption spectroscopy (TDLAS) sensors are widely used for measuring gas properties. These sensors offer several advantages including: small footprint, affordability, applicability to harsh environments, rapid time response, and calibration-free operation. As a result, diode-laser sensors can be integrated into control-systems and have previously been used to control gas-turbine combustors. In this study, high-frequency sine waves were generated continuously by a LabVIEW program to simultaneously scan and modulate the wavelength and intensity of a diode laser. The modulated laser light was transmitted 20 cm through the air and measured on a photodetector. Custom-built lock-in software was used to acquire …

Robust Bi-Directional Continuous Electrowetting Based On Metal-Semiconductor (M-S) Diodes, Qi Ni, Daniel E. Capecci, Millicent Schlafly, Nathan B. Crane

Faculty Publications

We demonstrate bi-directional continuous electrowetting by embedding metal-semiconductor diodes in the electrowetting substrate. Unlike conventional electrowetting on dielectric (EWOD), bi-directional continuous electrowetting uses a single electrode pair to actuate a droplet through long distances. As long as the voltage potential is maintained between two end electrodes, the droplet moves toward the electrode with the higher potential. However, previously reported material systems had limited success in repeated actuation. In this work, diodes based on Schottky barriers were fabricated by forming metal-semiconductor junctions between titanium and high resistivity n-type silicon. The performance enhancements were evaluated using current-voltage measurements of interface pairs. When …

Computational Fluid Dynamic Analysis Of Microbubble Drag Reduction Systems At High Reynolds Number, John D. Goolcharan

FIU Electronic Theses and Dissertations

Microbubble drag reduction (MBDR) is an effective method to improve the efficiency of fluid systems. MBDR is a field that has been extensively studied in the past, and experimental values of up to 80% to 90% drag reduction have been obtained. The effectiveness and simplicity of MBDR makes it a viable method for real world applications, particularly in naval applications where it can reduce the drag between the surface of ships and the surrounding water. A two dimensional single phase model was created in ANSYS Fluent to effectively model the behavior of bubble laden flow over a flat plate. This …

Contribution Of Fiber Undulation To Mechanics Of Three-Dimensional Collagen-I Gel, Shengmao Lin, Linxia Gu

Department of Mechanical and Materials Engineering: Faculty Publications

The collagen-I gel is extensively used as a scaffold material in tissue engineering due to its ability to mimic the extracellular matrix (ECM). In this study, the mechanics of collagen-I gel is investigated using a numerical model of three-dimensional collagen network. The resulted mechanical behavior was validated against the published experimental data. Results illustrated that fiber alignment was dominated in the low strain region, and its transition to stretching dominated phenomena at higher strain led to the strain stiffening of collagen gel. The collagen undulation at the microscopic level was found to delay the initiation of strain stiffening

Effects Of Electrode Off Centre On Trapped Thickness-Shear Modes In Contoured At-Cut Quartz Resonators, Junjie Shi, Cuiying Fan, Minghao Zhao, Jiashi S. Yang

Department of Mechanical and Materials Engineering: Faculty Publications

We investigated thickness-shear vibrations of a contoured, AT-cut quartz resonator with a pair of electrodes displaced from the resonator centre. The scalar differential equations by Stevens and Tiersten for thickness-shear vibrations of electroded and unelectroded quartz plates were employed. Based on the variational formulation of the scalar differential equations established in a previous paper and the variation-based Ritz method with trigonometric functions as basis functions, free vibration resonance frequencies and trapped thickness-shear modes were obtained. The effects of the electrode off centre on resonance frequencies and mode shapes were examined. When the electrode off centre is about one hundredth of …

The Effect Of Mesh-Type Bubble Breakers On Two-Phase Vertical Co-Flow, Alan Kalbfleisch

Electronic Thesis and Dissertation Repository

It is proposed that mesh-type bubble breakers can be used in two-phase gas-liquid vertical cocurrent pipe flow to enhance the heat and mass transfer rates. Two experimental studies were performed to investigate the effect of mesh-type bubble breakers with varying geometries on two-phase flow behaviour. The first used highspeed imaging to measure bubble size and observe the resulting flow regime for two-phase vertical co-flow consisting of air and water. A Froude number correlation that can be used to predict the bubble size generated by mesh-type bubble breakers is proposed. Flow regime maps for two-phase flow in the presence of bubble …

Micro Debris Generator, Gordan Bradaric, Ross Byers, Stephen Quanci

Mechanical Engineering

This senior project team at Cal Poly consisting of Stephen Quanci, Gordan Bradaric, and Ross Byers has been commissioned by Erik Brown of Lawrence Livermore National Labs to create a way to reliably and consistently entrain microscopic particles into the hot HTTU flow. These particles will be used to compare the loading rates of new HEPA filters by measuring the pressure drop across the filter. The generated particles would simulate typical conditions in which these HEPA filters are expected to operate, namely fine ash. The particles used for loading the filter are intended to simulate the particulate reaching the LLNL …

Efficiency Testing Of An Electronic Speed Controller, Grace Cowell, Matthew Hudson, Marcus Pereira

Mechanical Engineering

This project required the development of a rig that could experimentally determine the efficiency of an Electronic Speed Controller (ESC). The selected design focuses on measuring the losses due to heat from the device and comparing this to its input power. The selected design is a flow rig that utilizes the heat equation q=ṁcpΔT. The rig provides a steady state measurement of the ESC heat output by passing a known mass flow rate of air across the ESC and measuring the temperature difference. It uses a flowmeter to determine ṁ, thermocouples to determine ΔT, and a table lookup to determine …

Inclusive Lectern, Trent Canales, Sean Day, Dylan Sigley, Stephen Sippel

Mechanical Engineering

A lectern is an essential piece of equipment for almost all speeches and presentations. They come in many forms and range in degree of professionalism depending on the occasion. Lecterns not only hold a presenter’s notes, a microphone, or other presentation aids, they provide a structure for a presenter that can bolster their confidence during a presentation. As such, it is important that all presenters have a lectern available to them. Unfortunately this is not always the case due to lectern accessibility limitations. This problem inspired the Cal Poly Disability Resource Center to request a lectern that satisfies the Least …

Walker Tray, Marlene Troncoso, Judy Lantaca, Miriam Krage, Claire Francis

Mechanical Engineering

Sean is an individual with Cerebral Palsy, a disability that affects one's balance, muscle tone, muscular coordination, posture and control. Sean utilizes a walker to aid in maintaining his balance and muscular coordination when ambulating. This enables him to walk independently and leads to improved muscle strength and coordination. When walking, Sean places both hands on the walker to maintain balance and thus the ability to walk and carry items at the same time is compromised. Sean would like to be able to transport items while in use of his walker. The goals of this senior project design are to …

Transit Seating, Luke Mielke, Chris San Nicolas, Jon Rich, Sam Thompson

Mechanical Engineering

No abstract provided.

Compliant Air Skates, An Experiment, Samuel Feldtkeller, Cody Anderson, Kevin Daily, Eliana Stefani

Mechanical Engineering

There is currently a gap in the market of train levitation systems: wheeled trains and MagLev trains exist, but none utilize the low friction and high efficiency aspect of trains levitated by air skates. An air skate, is an air bearing that uses a pressure difference along its annular body to create a thin flow of air which is strong enough to "levitate" the weight of the skate. We have designed a compliant air skate that can glide over 0.04[in] defects in surfaces without touching down. After having made compliant skirts out of fiberglass and silicone, our setup of three …

Magnetic Bearing For Bently Nevada Rk4 Rotor Kits, Sean Fowler, Garrett Olson

Mechanical Engineering

Active Magnetic Bearings (AMB) are contact free bearings that support loads by magnetic levitation. This is accomplished by generating magnetic forces with electric current through a series of electromagnets surrounding a suspended rotor mass. Along with a set of electromagnets, an AMB assembly also consists of power amplifiers for each electromagnet, a controller, and proximity sensors. The proximity sensors provide rotor position feedback to the control system, which modulates power to the amplifiers [4]. Magnetic bearings are used in several industrial applications today, including but not limited to compressors, turbines, pumps, motors, and generators. Advantages of their utility include very …

Putter Measurement System, Bryan A.L. Hofferd, Yuzo Makitani, Jacob Phillips, Eric Stubben

Mechanical Engineering

This project is provided and funded by Callaway Golf Company for the Mechanical Engineering Department as a capstone project, also known as the Senior Project series: ME 428, 429, and 430. The title of the project proposal is "Putter Measurement System" in which our team must design, build, and test a system that meets the proposed objectives as stated by Callaway Golf. The need arises from the current systems’ inability to provide detailed and consistent measurements without tedious setup and calibration.

A Study Of Constant Voltage Anemometry Frequency Response, Alex D. Powers

Master's Theses

The development of the constant voltage anemometer (CVA) for the boundary layer data system (BLDS) has been motivated by a need for the explicit autonomous measurement of velocity fluctuations in the boundary layer. The frequency response of a sensor operated by CVA has been studied analytically and experimentally. The thermal lag of the sensor is quantified by a time constant, M_CVA. When the time constant is decreased, the half-amplitude cut-off frequency, f_CVA, is increased, thereby decreasing the amount of attenuation during measurements. In this thesis, three main approaches have been outlined in theory and tested experimentally …

Portable Sensory Room For The West Orange County Consortium For Special Education, Lindsey Chase, Emma Eskildsen, Alex Fox, Claire Francis, Nate Hoffman, Kaylee Keck, Sarah Sullivan

Biomedical Engineering

This report discusses the development of a Portable Sensory Room to be used at Newland Elementary School in Huntington Beach. Newland Elementary has an exceptional Special Needs program that teaches the children with the most severe cases of autism in its school district. People with autism typically also have sensory processing disorders, which can be extremely disruptive for a child’s development and can make it difficult for a child to be able to concentrate long enough to gain necessary life skills. The idea behind a Sensory Rooms is to create a place to calm the students and to expose them …

Experimental Building Demonstration Model With Viscous Fluid Dampers, Blake Thomas Reeve, Brianna Jean Kufa, Aden Malek Stepanians, Sophie Carmion Ratkovich

Architectural Engineering

The Architectural Engineering major places a heavy emphasis on structural dynamics and the role of wind and seismic loading in building analysis and design. Buildings of high importance that are critical to community function, such as hospitals, often utilize supplemental damping devices like supplemental viscous fluid dampers or base isolators to reduce the overall demands on the structural system. The design and analysis of these dampers are typically not taught at the undergraduate level, and is frequently performed by mechanical engineers, in lieu of structural engineers.

To better understand and research building behavior with supplemental damping devices, our multi-disciplinary team …

Focal Adhesion Kinase Regulation In Stem Cell Alignment And Spreading On Nanofibers, Mohammad Nahid Andalib, Jeong Soon Lee, Ligyeom Ha, Yuris A. Dzenis, Jung Yul Lim

Department of Mechanical and Materials Engineering: Faculty Publications

While electrospun nanofibers have demonstrated the potential for novel tissue engineering scaffolds, very little is known about the molecular mechanism of how cells sense and adapt to nanofibers. Here, we revealed the role of focal adhesion kinase (FAK), one of the key molecular sensors in the focal adhesion complex, in regulating mesenchymal stem cell (MSC) shaping on nanofibers. We produced uniaxially aligned and randomly distributed nanofibers from poly(L-lactic acid) to have the same diameters (about 130 nm) and evaluated MSC behavior on these nanofibers comparing with that on flat PLLA control. C3H10T1/2 murine MSCs exhibited upregulations in FAK expression and …

A Numerical Study Of Compressible Lid Driven Cavity Flow With A Moving Boundary, Amer Hussain

University of New Orleans Theses and Dissertations

A two-dimensional (2-D), mathematical model is adopted to investigate the development of circulation patterns for compressible, laminar, and shear driven flow inside a rectangular cavity. The bottom of the cavity is free to move at a specified speed and the aspect ratio of the cavity is changed from 1.0 to 1.5. The vertical sides and the bottom of the cavity are assumed insulated. The cavity is filled with a compressible fluid with Prandtl number, Pr =1. The governing equations are solved numerically using the commercial Computational Fluid Dynamics (CFD) package ANSYS FLUENT 2015 and compared with the results for the …

Characterization Of A Wind Tunnel For Use In Offshore Wind Turbine Development With Mitigation Measures For The Wall Effect Of Proximal Structures, James Newton

Electronic Theses and Dissertations

This thesis supports the development of the Harold Alfond W² Ocean Engineering Laboratory constructed at the University of Maine through several investigations conducted with a one-third scale wind generation system. The scale wind generator is first tested in what is considered an open-circuit wind tunnel configuration to determine the influence proximal building walls of a facility housing such a device may have on the consistency and capacity of a wind generator. Turbine performance testing with the wind generator to identify any susceptibility to proximal wall influence is also conducted. This is of interest as the full-scale system will operate …

Thermal Modeling For Light Armored Vehicle, Marc-André H. Brooks

Electronic Thesis and Dissertation Repository

Light Armored vehicles are required to operate in a variety of extremely hot and arid climates. As such, these vehicles are often subject to large heat gains due to environmental factors. The current systems employed for vehicle cooling do not always perform to the levels that are required, mainly due to the lack of a good estimate of the cooling load. A thermal analog circuit was created which separated each of the heat sources into its own module. Using material properties provided by General Dynamics Land Systems as well as information from acquired from CFD studies and ASHRAE, the values …

Design And Implementation Of A Controller For A Beaglebone Quadcopter, Peter Olejnik

Graduate Theses - Mechanical Engineering

Unmanned aerial vehicles are quickly becoming a significant and permanent feature in today's world of aviation. Amongst the various types of UAVs, a popular type is the quadcopter. Also referred to as a quadrotor, this rotor craft's defining feature is that it has four propellers. While its use is common in the hobbyist community, this aircraft's use within industry is blooming.

Presented are the efforts to design and implement a controller for a BeagleBone based quadcopter. As part of this effort, characteristics of the quadcopter were experimentally determined. These characteristics consist of physical properties of the quadcopter, such as the …

Jet Flow Validation Of Positron Emission Particle Tracking Utilizing High Speed Video, Seth Thomas Langford

Masters Theses

Positron Emission Particle Tracking (PEPT) generates 4D Lagrangian particle trajectories and is used to evaluate flow in granular media and complex geometries where optical interrogation methods are not possible. A Multi-Particle PEPT (Multi-PEPT) approach was developed by the University of Tennessee Thermal Fluids Group capable of finding and tracking many particles simultaneously to extend the utility of the PEPT method. This thesis compares 4,014 trajectories generated using the Multi-PEPT method with 3,055 trajectories generated from High Speed Video (HSV) data. All trajectories are acquired in an acrylic test section with water flow using resin beads. The flow geometry includes a …

Ascanius Project: Mech 401/402 Senior Capstone Experience, Ray H. Colquhoun, Joshua Solberg, Martin Tangari, Emanuel Di Stasio

Honors Thesis

This report describes the analysis, design, and test, and launch of a high power reusable rocket. The design goals were to reach a target altitude of 3000’, deploy a payload module containing an egg that can be safely recovered, and record flight video. The rocket was 62.13 in long fully assembled, had a dry mass of 2.764 kg (3.077 kg wet), and was propelled using an I-class solid fuel rocket motor (Cesaroni I-216-CL). The nose cone and tail cone were fabricated by the team from carbon fiber reinforced polymer (CFRP) via wet layup and vacuum bagging. The fins were constructed …

Numerical Investigation Of Full Scale Thunderstorm Downbursts: A Parametric Study And Comparison To Meteorological Model, Christopher Oreskovic

Electronic Thesis and Dissertation Repository

A series of Large Eddy Simulations using an atmospheric meteorological cloud model have been used to investigate the important geometric and thermal parameters that influence a thunderstorm downburst outflow, as it pertains specifically to the idealized cooling source model. A separate set of Large Eddy Simulations make use of the same idealized cooling source model, in a realistic atmospheric base state using real field sounding data, in an attempt to make a quantifiable comparison to a downburst from a full cloud simulation. Randomness has been added to the cooling source forcing function to mimic the thermal variation in a real …

Application Of Natural Convection For Photovoltaic Cooling And Photocatalytic Disinfection, Usman J. Rajput

Electronic Thesis and Dissertation Repository

Two investigations for improving renewable technologies are engaged. First is the examination of the enhancement of heat transfer at the rear of a hot photovoltaic panel by natural convection using various configurations and the other is analyzing a new photocatalytic collector for water heating and cleaning. A 20 Watt polycrystalline panel is exposed to indoor simulated solar light, under constant ambient temperature and stagnant wind conditions. Three configurations are considered: a partial heat sink, a water cavity and a water channel. The experimentally obtained convective heat transfer coefficients are 4.4 W•m^-2•K^-1 at the rear of the bare …

4-H Nfpa Fluid Power Challenge, Erika D. Bonnett

Engagement & Service-Learning Summit

The 4-H NFPA Fluid Power Challenge partnered Purdue Polytechnic Institute and Indiana 4-H with the National Fluid Power Association and Center for Compact and Efficient Fluid Power to provide teams of Indiana youth in 6-8th grades with opportunity to learn about hydraulics, engineering design, and other STEM skills. This created an opportunity to give youth a learning experience with STEM through hands-on, experiential learning activities. Youth experienced a one day workshop in which they worked as teams to learn concepts of fluid power through hands-on learning. Teams then went back to their communities and created and designed a fluid power …

Design And Analysis Of A Lift Assist Walker, Deep P. Shah

Master's Theses

Walkers provided stability to the elderly but cannot assist a person from sitting to standing. The objective of this project is to present the design and analysis of a lift assist walker. This report discusses the design and analysis of a collapsible lift assist walker capable of lifting a patient up to 250 lbs. from seated to standing in under 10 seconds. The designed walker utilized a two stage scissor mechanism with a gas spring assisted embedded linear actuator.