Biofuel Gasification For Residential Heating, Bryan Duke, Courtney Mcintosh, Jeron Hogan

Mechanical Engineering

No abstract provided.

Effects Of Ultrasonic Transducers On Heat Transfer In Packed Particle Beds, David Patrick Moseley

Masters Theses

The objective of this study was to determine the effects of ultrasonic transducers on heat transfer in a packed particle bed heat exchanger. Although substantial research has been devoted to ultrasound, and the associated improvements in heat transfer, data regarding the effects on packed particle beds is non-existent. This is of particular interest given the potential to improve heat transfer in a wide variety of packed particle bed systems. A 42.9% increase in the heat transfer rate was demonstrated as the result of improved fluid convection throughout the packed particle bed. Secondary effects, including acoustic cavitation, acoustic streaming and local …

Photovoltaic Cooking In The Developing World, Tyler Watkins, Christopher O'Day, Omar Arriaga

Mechanical Engineering

The challenge of clean cooking is faced by hundreds of millions of people worldwide. We present a cooking technology consisting of a solar panel directly connected to an electric heater in a well-insulated chamber. Assuming continued decrease in solar panel prices, we anticipate that in a few decades Solar Electric Cooking technologies will be the most common cooking technology for the poor. Appropriate use of insulation reduces the power demand making low-power Insulated Solar Electric Cooking systems already cost competitive.

Final Design Report: Allergen Mixing Assistant (Ama) Micro-Refrigeration Redesigning, Mitchell Parks, Minwoo (Michael) Suh

Mechanical Engineering

Abstract

Allergen Mixing Assistant (AMA) by Xtract Solutions is a device designed to more “effectively refrigerate, organize, and mix allergenic extracts”. Although Xtract Solutions intended the product to be fully automated, the company has decided against its automation and declared its current design as a minimum viable product whose components are too expensive, difficult to source and complex. Therefore, Cal Poly AMA design team - Mitchell Parks and Minwoo Suh - has decided to replace these expensive components with much more economical alternatives as shown below:

Stirling cooler

→

Thermoelectric (Peltier) cooler

Custom Arduino

Controller Card

→

TEC Thermostat *** …

Flow Field Dynamics In A High-G Ultra-Compact Combustor, Andrew E. Cottle

Theses and Dissertations

The Ultra Compact Combustor (UCC) presents a novel solution to the advancement of aircraft gas turbine engine performance. A high-g UCC design operates by diverting a portion of the axial compressor flow into a circumferential combustion cavity positioned about the engine outer diameter. The circumferential cavity (CC) provides the necessary residence length and time for combustion within reduced axial lengths; furthermore, high rates of centrifugal acceleration termed high-g loading are imposed upon the swirling cavity flow. These high-g conditions are hypothesized to increase flame speed, reduce flame length, and improve lean blow-out performance. Work at AFIT was sponsored by the …

Experimental Study And Numerical Simulation Of Methane Oxygen Combustion Inside A Low Pressure Rocket Motor, Mine Kaya

University of New Orleans Theses and Dissertations

In this thesis, combustion processes in a laboratory-scale methane based low pressure rocket motor (LPRM) is studied experimentally and numerically. Experiments are conducted to measure flame temperatures and chamber temperature and pressure. Single reaction-four species reacting flow of gaseous methane and gaseous oxygen in the combustion chamber is also simulated numerically using a commercial CFD solver based on 2-D, steady-state, viscous, turbulent and compressible flow assumptions. LPRM geometry is simplified to several configurations, i.e. Channel and Combustion Chamber with Nozzle and FWD. Flow in a Bunsen burner is simulated inside Channel geometry in order to validate the reaction model. Grid …

Laser Diagnostics Of C2h4 And Ch4 From N-Butane Pyrolysis, Liu Su

Masters Theses

Combustion of fossil fuels remains the dominant source of energy which enables us sustain thrive in this planet. Meanwhile, the negative effects of burning fossil fuels, however, are devastating our climate and environment. Eliminating those negative effects while attaining energy supply from fossil fuels becomes urgent and prominent. It is, nevertheless, impossible without a thorough understanding of the combustion process.

Experimental approach remains one of the dominating approaches to study combustion despite the growing interest in numerical approach. The development of workstations and massive supercomputers is providing the computation ability that one has never imaged. Nevertheless, it still appears difficult …

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 …

Me 350 Air Conditioning Experiment, Joshua Baida, Ellie Hallner, Tyler Eschenbach

Mechanical Engineering

In keeping with Cal Poly's focus on physically applying the concepts learned in the classroom, our team of engineering students has compiled a laboratory experiment displaying the basic thermodynamic cycle found in air conditioning systems. This vapor compression cycle is displayed on a visualization board that features all four major components of the system: the compressor, the evaporator, the condenser, and the throttling valve. Students will take measurements of temperature and pressure at each stage in the cycle and also gauge the power draw from the compressor to gain an understanding of how performance and electricity cost come into play …

Investigation Of Thermal Scaling Effects For A Turbine Blade Leading Edge And Pressure Side Model, Ryan A. Lynch

Theses and Dissertations

Recent experiments have attempted to quantify the overall cooling effectiveness at elevated temperature conditions. The Film Cooling Rig (FCR) at the Air Force Institute of Technology has been modified to better match the configuration of a similar large scale, low temperature rig at the Air Force Research Laboratory. This has enabled comparison and trend identification of how various properties scale from the low to high temperature condition. Various internal cooling and hole geometry configurations were investigated over a range of temperatures while utilizing the thermal scaling capability of Inconel 718. Film cooling trends and measures of overall effectiveness were matched, …

Gasoline Confined In Nano-Porous Media, Matthew Giso

Honors Theses

The heat of combustion was determined for gasoline confined in nano-porous media of differing pore size by bomb calorimetry. The heat of combustion of the confined fuels was comparable to that of bulk within the experimental uncertainty. This suggests that all of the confined fuel burns without any flame quenching and no chemical interactions at the interface between pore walls and fuel mitigate combustion.

Continuum Modeling Of The Densification Of W-Ni-Fe During Selective Laser Sintering, Connor M. West

Master's Theses

The purpose of this thesis is to effectively model the time history of the temperature distribution during the selective laser sintering process and use this information to investigate the resulting relative density. The temperature is a critical parameter of the process because it directly effects the overall quality of the part. First, an efficient, affordable, and reliable simulation was developed within the finite element software, Abaqus. Next, the results from the simulations were compared to the experimental results performed by Wang et al. (2016). The FEA model consisted of a 3 layer simulation. Multiple simulations at various laser recipes were …

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 …

Fluid Analysis In Solar Heat Pipes, Ben Krumholz, Michael Agavo, William Dundon

Mechanical Engineering

Evacuated tube solar collectors are efficient systems that use heat pipes to facilitate heat transfer. They use incoming solar radiation to heat water. Professor Mason Medizade tasked the team with choosing a component of the system to research and test its influence on system performance. The team investigated the working fluid that runs through the heat pipes. Distilled water, acetone, and ethanol at a range of fill volumes form 1 mL to 11 mL were tested. The team's goal was to find a volume for each fluid to maximize performance of the system. Performance was defined as average temperature rise …

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 …

Heat Of Fusion Of Primary Alcohol Confined In Nanopores, Harrisonn Griffin

Honors Theses

Melting behavior of physically confined 1-decanol in nano porous silica was probed using a Differential Scanning Calorimeter (DSC). In agreement with the Gibbs-Thomson prediction, we observe that the melting temperature of the confined 1-decanol scales inversely with the physical size of the pores. Contrary to the assumption used in developing the Gibbs-Thomson equation, however, the apparent heat of fusion decreases as the pore size decreases. Previously, several models have been proposed where interfacial layers of molecules do not participate in the phase transition and thereby would not contribute to the heat of fusion. While these could reconcile the seeming contradiction, …

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 …

Effect Of Non-Uniform Air-Side Velocity Distribution On Heat Transfer Model Predictions For Microchannel Condenser., Zachary Chapin

Electronic Theses and Dissertations

This is a study of the effects on heat transfer capacity predictions of microchannel condensers when airflow is maldistributed due to the shape of the condenser. The three shapes investigated in this study are flat, U-shape and roll. Each coil was tested in a water calorimeter and those results were compared to the model prediction. The model prediction was calculated using CoilDesigner™ modeling software with standard correlations. Using the uniform airflow assumption, the model over predicted the heat capacity measured in the calorimeter by 5-11% depending on the coil and inlet conditions. The local airflow velocity was measured using a …

Improved Modeling Of Atmospheric Entry For Meteors With Nose Radii Between 5cm And 10m, Jakob Dale Brisby

Masters Theses

Atmospheric entry studies typically look closely at the peak heating rate that a body encounters during its trajectory. This is an extremely important phenomenon to study because it allows engineers to determine if a trajectory is possible with given materials and craft design specifications. It also allows designers to choose what type of method will be used for mitigating the enormous heat fluxes during entry. In general, it is accepted that during the super-sonic flight regime the body will continue to be heated and an ablative heat shield often is used to deal with these heating processes. The theory outlined …

Study To Reduce Peak Electrical Demand Charges For The John C. Hodges Library, Jared Thomas Carpenter, Isaac Michael Robinette, Matthew Joeseph Conrad, Daniel Matthew Whaley, William A. Miller

Chancellor’s Honors Program Projects

No abstract provided.

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 …

A Model For Complex Heat And Mass Transport Involving Porous Media With Related Applications, Furqan A. Khan

Electronic Thesis and Dissertation Repository

Heat and mass transfer involving porous media is prevalent in, for example, air-conditioning, drying, food storage, and chemical processing. Such applications require non-equilibrium heat and mass (or moisture) transfer modeling inside porous media in conjugate fluid/porous/solid framework. Moreover, modeling of turbulence and turbulent heat and mass transfer becomes essential for many applications. A comprehensive literature review shows a scarcity of models having such capabilities. In this respect, the objectives of the present thesis are to: i) develop a formulation that simulates non-equilibrium heat and mass transfer in conjugate fluid/porous/solid framework, ii) demonstrate the capabilities of the developed formulation by simulating …

Application Of A Multi-Zone Model For The Prediction Of Species Concentrations In Rapid Compression Machine Experiments, David Wilson

Master's Theses (2009 -)

Accurate chemical kinetic models, which predict species evolution and heat release rates in chemically reactive systems, are essential for further advancements in fuel and combustion technology. An experimental facility that is widely used for evaluating the accuracy of kinetic models is a rapid compression machine (RCM), which creates a well-defined reaction environment by compressing a reactive mixture inside a chamber. Generally, RCM experiments are conducted in order to obtain ignition delay data. However, chemical speciation data provides greater insight into reaction pathways, and is therefore a more rigorous benchmark for validating kinetic models. In order for a chemical kinetic model …

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 …

Economical Retrofit System To Reduce Cooking Emissions In Third World Dwellings, Jonathan Vanzummeren, Tyler Sturgeon, Ben Dalessandro

Williams Honors College, Honors Research Projects

Abstract:

The purpose of this document is to propose and demonstrate the feasibility and effectiveness of substituting an open flame biomass cooking process with a closed system with the capabilities of sustaining an adequate fire. Clay ovens or “chulhas” are the traditional piece of cooking equipment used in poorer areas of the world. They are often built inside cramped one-room housing units with little or no ventilation. The emissions released from burning fuel sources such as wood, coal, or animal waste bring with them detrimental and often fatal health problems and results in approximately 1.3 million deaths per year.

The …

Solar Thermal Collector, Hazel Tickner, Tyson Nakamura

All Undergraduate Projects

During the course of this project, a solar thermal collector and supporting stand were designed and manufactured to be used during Mechanical Engineering Technology labs. Students will be able to use the collector to heat water, with the sun being the only heat source. The collector was designed by calculating surface area limitations, estimated solar input, and desired efficiency, to find the required water flow rate. From there, the necessary pipe lengths and diameters were determined, and the solar thermal collector was constructed. Two pipe paths were manufactured: a curved path, and a manifold path. Students will be able to …

Oscillating Heat Pipe Performance With Evaporator Section Modifications, Mitchell Hoesing

Electronic Theses and Dissertations

The continuous development of electronic components to become faster and smaller has led to an increasing problem with thermal management. Thermal management ensures that the component operating temperatures are within a safe range, which maintains performance and improves reliability and lifespan. Traditional thermal management devices, such as the extruded-fin heat sink, are incapable of maintaining the safe operating temperature range for current and future high heat flux cooling applications. A device that has the capability to meet this growing need is the oscillating heat pipe. Oscillating heat pipes (OHPs) are passive, two-phase cooling devices that have been shown to transfer …

An Experimental Investigation Of Heat Transfer For Arrays Of Impingement Jets Onto The Featured Surfaces With Cylindrical And Elliptical Raised Surfaces, Marc A. Medina

Honors Undergraduate Theses

This study focuses on multi-jet impingement for gas turbine geometries in which the objective is to understand the influence of the roughness elements on a target surface to the heat transfer. Current work has proven that implementing roughness elements for multi-jet impingement target surfaces has increased heat transfer ranging anywhere from 10-30%. This study has chosen to investigate three different roughness elements, elliptical in cross-section, to compare to smooth surface geometries for multi-jet impingement. An experimental was taken for this study to extend the current knowledge of multi-jet impingement geometries and to further understand the heat transfer performance. A temperature …

An Assessment Of The Validity Of The Kinetic Model For Liquid-Vapor Phase Change By Examining Cryogenic Propellants, Kishan Bellur

Dissertations, Master's Theses and Master's Reports

Evaporation is ubiquitous in nature and occurs even in a microgravity space envi- ronment. Long term space missions require storage of cryogenic propellents and an accurate prediction of phase change rates. Kinetic theory has been used to model and predict evaporation rates for over a century but the reported values of accommodation coefficients are highly inconsistent and no accurate data is available for cryogens. The proposed study involves a combined experimental and computational approach to ex- tract the accommodation coefficients. Neutron imaging is used as the visualization technique due to the difference in attenuation between the cryogen and the metallic …