Heat Transfer, Combustion Commons^™

Simulations Of Impinging Jet With A Range Of Configuration, Devansh Singh

Electronic Theses and Dissertations

Impinging jet technique is widely increasing across the globe due to its ability to produce high heat and mass transfer as compared to other traditional methods. Three cases of impinging jets related to cooling technologies for a gas turbine were investigated. The first case involves a single jet impinging on a flat plate. The second case has an array of jets impinging on a curved surface. The third case deals with simulating impinging jet in crossflow. The first case was used for validation and shows the effect of mesh and inlet boundary conditions. After careful observation, it was seen that …

Heat Transfer Analysis In A Paddle Reactor For Biomass Fast Pyrolyis, Ankith Ullal

Dissertations, Master's Theses and Master's Reports

Heat transfer analysis was performed on a novel auger reactor for biomass fast pyrolysis. As part of this analysis, correlations for specific heat capacity and heat transfer coefficients for biomass (sawdust) and sand (used as heat transfer medium) were developed. For sand, the heat transfer coefficient followed a power law distribution with reactor fill level and temperature. For raw biomass, the heat transfer coefficient also showed similar dependence on fill level, but was independent of temperature up to 300°C. These correlations were used in a one dimensional heat transfer model developed to calculate the heating time and heating rate of …

Extending The Upper Temperature Range Of Microchip Gas Chromatography Using A Heater/Clamp Assembly, Abhijit Ghosh, Jacob E. Johnson, Johnathan G. Nuss, Brittany A. Stark, Aaron R. Hawkins, Luke T. Tolley, Brian D. Iverson, H. Dennis Tolley, Milton L. Lee

Faculty Publications

Miniaturization of gas chromatography (GC) instrumentation is of interest because it addresses current and future issues relating to compactness, portability and field application. While incremental advancements continue to be reported in microchip GC, the current performance is far from acceptable. This lower performance compared to conventional GC is due to factors such as pooling of the stationary phase in corners of non-cylindrical channels, adsorption of sensitive compounds on incompletely deactivated surfaces, shorter column lengths and less than optimum interfacing to injector and detector. In this work, a microchip GC system was developed that solves the latter challenge, i.e. microchip interfacing …

The Emission And Particulate Matter Oxidation Performance Of A Scr Catalyst On A Diesel Particulate Filter With A Downstream Scr, Sagar Sharma

Dissertations, Master's Theses and Master's Reports

Selective catalytic reduction (SCR) systems along with a NH₃ slip control catalyst (ASC) offers NOₓ conversion efficiency >90 % with NH₃ slip < 20 ppm. However, future heavy duty diesel (HDD) engines are designed for higher engine-out NOₓ to improve fuel consumption. Consequently, there is a strong desire to further improve the NOₓ reduction performance of SCR systems, to meet the 2015 California Optional Low NOₓ Standard. SCR catalysts on a diesel particulate filter provide an effective solution to reduce NOₓ and PM using a single aftertreatment device. It also provides an opportunity to increase the SCR volume to achieve NOₓ conversion efficiency >95 %. A downstream SCR catalyst substrate can be used to get additional NO_x conversion by using the SCRF^® outlet NH₃ to increase the cumulative NOₓ conversion of the system.

In this study, NOₓ reduction, NH₃ slip and PM oxidation performance of a Cu-zeolite SCRF^® with a downstream Cu-zeolite SCR were investigated based on engine experimental data at steady state conditions. The experimental data were collected at varying SCRF^® inlet temperatures, space velocities, inlet …

Impact Of Natural Gas Direct Injection On Thermal Efficinecy In A Spark Ignition Engine, James Sevik

Dissertations, Master's Theses and Master's Reports

Interest in natural gas as an internal combustion engine fuel has been renewed due to its increasing domestic availability and stable price relative to other petroleum fuel sources. Natural gas, comprised mainly of methane, allows for up to a 25% reduction in engine out CO2 emissions due to a more favorable hydrogen-to-carbon ratio, relative to traditional petroleum sources. Traditional methods of injecting natural gas can lead to poor part-load performance, as well as a power density loss at full load due to air displacement in the intake manifold. Natural gas direct injection, which allows the fuel to be injected directly …

Experimental Investigations Of Temperature Controlled Innovative Annular Flow-Boiling Of Fc-72 In Millimeter Scale Ducts – Steady And Enhanced Pulsatile Realizations, Patcharapol Gorgitrattanagul

Dissertations, Master's Theses and Master's Reports

Steady and steady-in-the-mean shear driven annular flow-boiling is experimentally investigated in this thesis. By annular flow-regime one means separated liquid and vapor flows with the flowing liquid film staying on the boiling-surface.

The goals for the steady annular flow-boiling operations are to better understand relative importance of heat-transfer mechanisms (nucleation versus convective phase-change, with convective meaning absence of nucleation) and to develop better quantitative characterizations/correlations for heat-transfer rates. The goals for the steady-in-the-mean annular investigations was to explore improved means of significantly increasing heat transfer rates - while retaining the flow-regime's annularity.

The experimental investigations (with FC-72 as a working …

Effect Of Spark Advance And Fuel On Knocking Tendency Of Spark Ignited Engine, Abhay S. Joshi

Dissertations, Master's Theses and Master's Reports

Knock, in spark ignition engine is the combustion caused by the autoignition of the fuel-air mixture. It is the phenomenon that limits engine performance and thermal efficiency. Knock also has an adverse effect on emissions and fuel economy. Engine designers target engines with maximum power and torque output without compromising on fuel economy. Engine downsizing is the method generally adopted. The main goal of engine downsizing is to achieve better fuel economy while increasing the power and torque output of the engine. Better fuel economy is achieved by reducing the displaced volume which in turn means a much higher brake …

Simulation Of Diesel Particulate Filter Regeneration Using Lattice Boltzmann Method, Kshitiz Kumar Jain

Dissertations, Master's Theses and Master's Reports

Lattice Boltzmann Method is a novel approach, which has shown promise in solving a wide variety of fluid flow problems including single and multi-phase flows in complex geometries. Volume elements of the fluid domain are considered to be composed of particles and these particles fall under a velocity distribution function at each grid point. Particles collide with each other under the influence of external forces and the rules of collision are defined so as to be compatible with the Navier-Stokes Equation. In the current work, LBM has been applied to Diesel Particulate filters which is a device used for reducing …

Turbulent Transition Simulation And Particulate Capture Modeling With An Incompressible Lattice Boltzmann Method, John R. Murdock

Dissertations, Master's Theses and Master's Reports

Derivation of an unambiguous incompressible form of the lattice Boltzmann equation is pursued in this dissertation. Further, parallelized implementation in developing application areas is researched. In order to achieve a unique incompressible form which clarifies the algorithm implementation, appropriate ansatzes are utilized. Through the Chapman-Enskog expansion, the exact incompressible Navier-Stokes equations are recovered. In initial studies, fundamental 2D and 3D canonical simulations are used to evaluate the validity and application, and test the required boundary condition modifications. Several unique advantages over the standard equation and alternative forms found in literature are found, including faster convergence, greater stability, and higher fidelity …

Incorporation Of Higher Carbon Number Alcohols In Gasoline Blends For Application In Spark-Ignition Engines, Kristina Lawyer

Dissertations, Master's Theses and Master's Reports

The 2007 U.S. Renewable Fuel Standard (RFS2) requires an increase in the use of advanced biofuels up to 36 billion gallons by 2022. Higher carbon number alcohols, in addition to cellulosic ethanol and synthetic biofuels, could be used to meet this demand while adhering to the RFS2 corn-based ethanol limitation. Alcohols of carbon numbers 2 through 8 are chosen based on their chemical and engine-related properties.

Blend comparison metrics are developed from automotive industry trends, consumer expectations, U.S. fuel legislation, and engine requirements. The metrics are then used to create scenarios by which to compare higher alcohol fuel blends to …

Model-Based Control Of Hybrid Electric Powertrains Integrated With Low Temperature Combustion Engines, Ali Soloukmofrad

Dissertations, Master's Theses and Master's Reports

Powertrain electrification including hybridizing advanced combustion engines is a viable cost-effective solution to improve fuel economy of vehicles. This will provide opportunity for narrow-range high-efficiency combustion regimes to be able to operate and consequently improve vehicle’s fuel conversion efficiency, compared to conventional hybrid electric vehicles (HEV)s. Low temperature combustion (LTC) engines offer the highest peak brake thermal efficiency reported in literature, but these engines have narrow operating range. In addition, LTC engines have ultra-low soot and nitrogen oxides (NOx) emissions, compared to conventional compression ignition and spark ignition (SI) engines. This dissertation concentrates on integrating the LTC engines (i) in …

Simulation Study On Effect Of Gas Charging And Egr In A Dual-Fuel Engine, Satyavenkata Naga Sai Sharath Gorthy

Dissertations, Master's Theses and Master's Reports

Natural gas combined with diesel as micro pilot has the capabilities of achieving lower NOx and soot emissions. Optimization of the combustion process in engines with natural gas and diesel micro-pilot is essential to achieve higher efficiencies and loads. Gas charging (intake air boosting) and EGR are two technologies which when implemented in the natural gas-diesel engines, provide the opportunity to achieve higher efficiencies and loads and low emissions. Simulation study is one of the approaches to investigate the extent and effects of gas charging and EGR on the performance of the engine. With the rapid improvements over the past …

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.

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 …

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 *** …

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

Mechanical Engineering

No abstract provided.

Models For Decanting Gaseous Fuel Tanks: Simulations With Gfssp Thermal Model, Kailash Kumar Jain Munoth

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Transport of fuel from distillation/storage plant to different parts of the world has always been challenging task for Engineers. Different methods have been proposed over the time for transporting fuel efficiently and at low cost which include Marine vessels, Pipelines, Rail Cars and Trucks. In order to transport useful amount of fuel in a reasonably sized tank, we have to liquefy it. While few fuels are easy to liquefy there are great number of fuels which liquefy only under extreme pressure/temperature conditions. Methane has a boiling point of -161.7°C at atmospheric pressure which means it has to be cooled to …

Determination Of Aqueous Surfactant Solution Surface Tensions With A Surface Tensiometer, Remelisa Esteves, Birce Dikici Ph.D, Matthew Lehman, Qayyum Mazumder, Nonso Onukwuba

Beyond: Undergraduate Research Journal

Surfactant solutions are applicable to engineering systems for cooling equipment for electronics. Surfactants can be added to water to improve heat transfer. An application of using aqueous surfactant solutions can be through microchannel heat sink. Although it is ideal to redesign these systems to reduce heat, it is a costly method. Surfactant solutions at optimal solution concentration can be able to transfer heat quickly and effectively with minimum expense. The surface tension of surfactant solutions is an important parameter for boiling heat transfer and must be taken into consideration. The purpose of this research is to measure surface tension of …

Determination Of Surfactant Solution Viscosities With A Rotational Viscometer, Remelisa Esteves, Nonso Onukwuba, Birce Dikici Ph.D

Beyond: Undergraduate Research Journal

Aqueous surfactant solutions are used in engineering systems for improving boiling heat transfer. The purpose of this research is to determine the viscosities of surfactant solutions and to investigate the effect of composition on viscosity. The results obtained can possibly be used as reference for further study in the effects of surfactant solution viscosities on nucleate boiling. A rotational viscometer was used to determine the viscosities of three surfactant solutions – SLS, EH-14, and SA-9 – of various compositions at room temperature. It was discovered that the viscosities of SLS, EH-14, and SA-9 had a nearly consistent pattern as their …

Numerical Simulation On The Combustion Characteristic Of Iron Ore Sintering With Flue Gas Recirculation, Gan Wang, Zhi Wen, Guofeng Lou, Ruifeng Dou, Xunliang Liu, Fuyong Su, Sizong Zhang

The 8th International Conference on Physical and Numerical Simulation of Materials Processing

No abstract provided.