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Book An Experimental Study of High pressure Droplet Combustion

Download or read book An Experimental Study of High pressure Droplet Combustion written by Chris M. Norton and published by . This book was released on 1990 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Experimental Investigation of Droplet Combustion at High Pressures

Download or read book Experimental Investigation of Droplet Combustion at High Pressures written by R. Natarajan and published by . This book was released on 1969 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Droplets and Sprays

Download or read book Droplets and Sprays written by Saptarshi Basu and published by Springer. This book was released on 2017-12-11 with total page 433 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book focuses on droplets and sprays relevant to combustion and propulsion applications. The book includes fundamental studies on the heating, evaporation and combustion of individual droplets and basic mechanisms of spray formation. The contents also extend to the latest analytical, numerical and experimental techniques for investigating the behavior of sprays in devices like combustion engines and gas turbines. In addition, the book explores several emerging areas like interactions between sprays and flames and the dynamic characteristics of spray combustion systems on the fundamental side, as well as the development of novel fuel injectors for specific devices on the application side. Given its breadth of coverage, the book will benefit researchers and professionals alike.

Book Dust Explosion Dynamics

Download or read book Dust Explosion Dynamics written by Russell A. Ogle and published by Butterworth-Heinemann. This book was released on 2016-09-10 with total page 687 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dust Explosion Dynamics focuses on the combustion science that governs the behavior of the three primary hazards of combustible dust: dust explosions, flash fires, and smoldering. It explores the use of fundamental principles to evaluate the magnitude of combustible dust hazards in a variety of settings. Models are developed to describe dust combustion phenomena using the principles of thermodynamics, transport phenomena, and chemical kinetics. Simple, tractable models are described first and compared with experimental data, followed by more sophisticated models to help with future challenges. Dr. Ogle introduces the reader to just enough combustion science so that they may read, interpret, and use the scientific literature published on combustible dusts. This introductory text is intended to be a practical guide to the application of combustible dust models, suitable for both students and experienced engineers. It will help you to describe the dynamics of explosions and fires involving dust and evaluate their consequences which in turn will help you prevent damage to property, injury and loss of life from combustible dust accidents. Demonstrates how the fundamental principles of combustion science can be applied to understand the ignition, propagation, and extinction of dust explosions Explores fundamental concepts through model-building and comparisons with empirical data Provides detailed examples to give a thorough insight into the hazards of combustible dust as well as an introduction to relevant scientific literature

Book An Experimental Investigation of the Effect of Fuel Droplet Size on the Vaporization Process in a Turbulent Environment at Elevated Temperature and Pressure

Download or read book An Experimental Investigation of the Effect of Fuel Droplet Size on the Vaporization Process in a Turbulent Environment at Elevated Temperature and Pressure written by Cameron Mark Verwey and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The performance of liquid-fuelled spray combustion systems has a massive impact on the efficiency of energy production in many sectors across the globe. Realistic combustors generate sub 100-μm droplets and operate under high pressure and temperature in strong turbulence. Investigations into droplet evaporation and combustion provide fundamental knowledge and validation data regarding the behaviour of sprays, and although single droplet approaches have been a staple of energy research for many decades, there is little information regarding the effect of turbulence and initial diameter, especially micro-sized, on droplet evaporation rates. The present experimental study develops, interprets, and correlates the results of almost 500 tests performed on isolated heptane and decane droplets. Droplets in the range of 110 - 770 μm (initial diameter) were generated and suspended on small intersecting micro-fibers in a spherical fan-driven chamber and exposed to quasi-zero mean turbulence of intensity up to 1.5 m/s, temperatures ranging from 25 - 100°C, and pressures between 1 and 10 bar. The results indicate that droplet size has a major influence on evaporation rate, as measured by the temporal reduction in droplet surface area, when the environment is turbulent. Evaporation rates increased with both initial diameter and turbulence intensity at all test conditions. The effectiveness of turbulence, defined as the ability of turbulence to improve the evaporation rate over the rate of a stagnant droplet at identical ambient conditions, increased with pressure but decreased with temperature. Both the ratio of Kolmogorov length scale to droplet diameter and the theoretical molar concentration gradient of fuel at the droplet surface are found to be excellent predictors of turbulence effectiveness. Correlation approaches utilizing a turbulent Reynolds number or a vaporization Damköhler number are suggested to predict the evaporation rate of a single droplet exposed to a purely turbulent flow field.

Book Studies on Droplet Evaporation and Combustion in High Pressures

Download or read book Studies on Droplet Evaporation and Combustion in High Pressures written by J. Sato and published by . This book was released on 1993 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Study of the Sub and Supercritical Behavior of Fuel Droplets

Download or read book Study of the Sub and Supercritical Behavior of Fuel Droplets written by and published by . This book was released on 2001 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: A study of the droplet gasification and combustion characteristics of hydrocarbon fuel droplets was conducted at sub- and supercritical. The experimental setup provided quiescent and convective environments under supercritical pressure and temperature conditions. The droplet combustion experiment hardware consisted of: a liquid pressurizing and transfer system; a high pressure and temperature combustion chamber; a droplet formation, deployment and ignition system; and a high speed CCD imaging system. The gasification and combustion characteristics of droplets of several hydrocarbons under quiescent environments were studied. Specifically, the mass emission rates and combustion characteristics of 1.5-mm-diameter suspended droplets of a series of hydrocarbons ranging from hexane (C6) to tetradecane (Cl4) were measured at sub- and supercritical pressures and temperatures using the high-speed image system. The images of droplet gasification and combustion revealed interesting phenomena and provided better understanding of the droplet behavior in sub- and supercritical pressure and temperature environments.

Book Scientific and Technical Aerospace Reports

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 702 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Combustion Dynamics of Liquid Droplets and Turbulent Jets Relevant to Rocket Engines

Download or read book Combustion Dynamics of Liquid Droplets and Turbulent Jets Relevant to Rocket Engines written by Miguel Angel Plascencia Quiroz and published by . This book was released on 2021 with total page 225 pages. Available in PDF, EPUB and Kindle. Book excerpt: These experiments examined the reactive processes involving nanoparicle laden liquid droplets, and turbulent jet flames as two separate sets of studies. The first part of this dissertation (Chapters 2 and 3) deals with the combustion of ethanol liquid droplets loaded with nano particulate additives using different droplet formation methods. For this study, an apparatus at the Energy and Propulsion Research Laboratory at UCLA was used to keep the droplet in a quiescent environment. Three different types of droplet combustion experiments were performed, involving: (I) the classic single droplet suspended from a quartz fiber, (II) a single droplet suspended from a quartz capillary, (III) a burning droplet that has continual fuel deliver to sustain the droplet for longer periods of time during the combustion process. Two alternative nanoparticles were explored to demonstrate the effect of energetic additives: reactive nano aluminum (nAl) and inert nano silicon dioxide (nSiO2), each having nominal average diameters of 80 nm. Simultaneous high speed visible and OH* chemiluminescence images were taken to determine the shape of the droplet over time and hence the burning rate constant (K), flame standoff distance, and mean OH* chemiluminescence intensity with varying particulate concentrations. Visible imaging showed particle/vapor ejections and jetting in continuously fed droplet experiments, while rod-suspended burning droplets showed limited particle ejection, usually towards the end of the droplet lifetime. The nSiO2-laden, rod-suspended droplets formed a porous, shell-like structure resembling the shape of a droplet at higher nSiO2 concentrations, in contrast to smaller residue structures left for nAl-laden droplets. A systematic increase in the burning rate constant was observed as the loading concentration of nAl was increased from 1wt%-6wt%. The droplet with continual fuel delivery had the greatest improvement in K of 13% over the pure fuel value. For nSiO2, the continuously fed droplet showed the greatest increase of 5% at 1 wt% loading concentrations, and no consistent trend was observed for nSiO2, likely due to the large shell-like residue structures in the latter stages of combustion. Transmission electron microscopy (TEM) images of particle residue revealed additional insights.The second part of this dissertation (Chapters 4 and 5) studied reacting gaseous turbulent jets in a newly constructed experiment at the Air Force Research Laboratory (AFRL/RQR) located at Edwards Air Force base. This experimental study aimed to characterize the coupling of an acoustic field with a turbulent gaseous methane nonpremixed flame under atmospheric pressure conditions. Two separate injection configurations were examined: one that involved a classic single methane jet surrounded by a minimal velocity oxidizer co-flow and a second coaxial jet configuration with annular oxidizer flow and the same low-velocity co-flow. The different jets were placed within an acoustic waveguide in which standing waves could be created using several speakers. The reacting jets could thus be situated at either a pressure node or a pressure anti-node location. High-speed Schlieren and OH* chemiluminescence images recorded the near field behavior of the flame under both unforced and acoustically forced conditions. High-speed imaging showed two different phenomena associated with these standing waves. When the flame was forced while situated at a pressure node, a sinuous oscillatory response of the flame was observed, in addition to transverse oscillations of the center fuel jet, which shortened the intact fuel core length. The flame "flattened" into an ellipsoidal shape in the direction of the acoustic waves. Conversely, at a pressure anti-node, the coupling of the acoustics and flame gave rise to an axisymmetric response (puff-like oscillations), which prompted the flame to become unstable at the anchoring region. This could lead to periodic liftoff or permanent flame liftoff. A receptivity study for a methane jet at Reynolds number of 5,300 and an ambient oxygen concentration of 40\% showed that the reacting jet was able to respond at the frequency of the unsteady acoustic field for a range of frequencies, but with a diminishing response of the flame for both the pressure node and the pressure anti-node under high frequency excitation. Proper Orthogonal Decomposition (POD) analysis was able to extract mode shapes and frequencies based on pixel intensity fluctuations. For the cases of pressure node forcing, this analysis method illustrated the different modes of flame oscillation, in many cases which were similar to corresponding low Reynolds number fuel jet experiments with pressure node excitation conducted at UCLA. A forcing susceptibility diagram was created to map the three different anchoring stability regimes the flame experienced under pressure anti-node forcing, demonstrating the need for higher amplitude excitation required for the flame to lift off when forced at higher frequency pressure anti-node conditions. As an extension to the single jet, the shear coaxial jet configuration kept the center fuel and surrounding oxidizer co-flow constant. Only the outer annular oxidizer flowrate was varied, with annulus-to-inner jet velocity ratios ranging from R = 0.05 to 0.3, to investigate its impact on the flame's ability to respond to the acoustics. In the absence of acoustic excitation, the coaxial jet did demonstrate natural shear layer/wake like instabilities at higher annular-to-jet velocity ratios, for R = 0.17 and 0.3. The dynamical response of the coaxial jet to pressure node excitation exhibited similar characteristics to that of the single jet for a range of forcing frequencies. But when forced at a pressure anti-node, a notable difference between the two configurations was found. The shear coaxial jet was more responsive to the acoustic forcing at higher forcing frequencies, for example, than the single fuel jet. The susceptibility diagrams for the full range of annular-to-inner jet velocity ratios demonstrated opposite trends when compared to the single jet, that is, that the coaxial jet was more responsive to excitation at a given excitation amplitude when the forcing frequency was higher, and thus closer to the natural coaxial jet instability frequency. Hence evidence suggests that the natural instabilities of the coaxial jet shear layer may be causing the difference in susceptibility diagrams. Both sets of experimental studies here, the nanofuel droplet combustion studies and the acoustically-coupled turbulent fuel jet combustion experiments, provide useful advances to our understanding of reactive flows relevant to liquid rocket engine systems. Enhancement in burning rates with nanoparticulate additives show potential benefits for rocket fuels, and attendant benefits are documented in the presence of acoustic disturbances, studied separately [1]. AFRL-based acoustically coupled turbulent fuel jet studies reveal different dynamical characteristics, depending on the injection system and the acoustic frequency and amplitude range. Different characteristic signatures extracted via POD analysis are both relevant in understanding combustion instabilities and in developing reduced order models underlying control of such instabilities. The present studies contribute to these goals in important ways.

Book Combustion of Liquid Fuel Sprays

Download or read book Combustion of Liquid Fuel Sprays written by Alan Williams and published by Butterworth-Heinemann. This book was released on 2013-10-22 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt: Combustion of Liquid Fuel Sprays outlines the fundamentals of the combustion of sprays in a unified way which may be applied to any technological application. The book begins with a discussion of the general nature of spray combustion, the sources of liquid fuels used in spray combustion, biomass sources of liquid fuels, and the nature and properties of fuel oils. Subsequent chapters focus on the properties of sprays, the atomization of liquid fuels, and the theoretical modeling of the behavior of a spray flame in a combustion chamber. The nature and control of pollutants from spray combustion, the formation of deposits in oil-fired systems, and the combustion of sprays in furnaces and engines are elucidated as well. The text is intended for students undertaking courses or research in fuel, combustion, and energy studies.

Book Fourth International Microgravity Combustion Workshop

Download or read book Fourth International Microgravity Combustion Workshop written by and published by . This book was released on 1997 with total page 546 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book An Experimental Test Facility for Studying the Effects of Turbulence on the Evaporation of Fuel Droplets at Elevated Pressure and Temperature Conditions

Download or read book An Experimental Test Facility for Studying the Effects of Turbulence on the Evaporation of Fuel Droplets at Elevated Pressure and Temperature Conditions written by Sean Fabbro and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: