Download or read book Flame Spreading Over Thin Fuel Samples in Partial Gravity Environments written by Kurt R. Sacksteder and published by . This book was released on 1998 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Numerical Study of Flame Spread Over Thin Cellulosic Fuels in Microgravity written by Yang Long and published by . This book was released on 2007 with total page 348 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Concurrent Flow Flame Spread Over Ultra Thin Discrete Fuels in Microgravity written by Ama R. Carney and published by . This book was released on 2020 with total page 125 pages. Available in PDF, EPUB and Kindle. Book excerpt: Microgravity experiments are performed to study wind-assisted flame spread over discrete fuel elements. Ultra-thin cellulose-based fuel segments are distributed uniformly in a low-speed flow and flame spread is initiated by igniting the most upstream fuel segment. Similar to continuous fuels, flame spread over discrete fuels is a continual process of ignition. Flame propagation across a gap only occurs when a burning fuel segment, before it burns out, ignites the subsequent segment. During this process, gaps between samples reduce the fuel load, increasing the apparent flame spread rate and decreasing the heat transfer between adjacent segments. The reduction in heat transfer decreases the solid burning rate. In this study, sample segment length, gap size, and imposed flow velocity are varied to study the impacts on burning characteristics, including propensity of flame spread, flame spread rate, and solid burning rate. Detailed profiles of the transient flame spread process are also presented.
Download or read book A Gallery of Combustion and Fire written by Charles E. Baukal, Jr. and published by Cambridge University Press. This book was released on 2020-09-03 with total page 193 pages. Available in PDF, EPUB and Kindle. Book excerpt: A Gallery of Combustion and Fire is the first book to provide a graphical perspective of the extremely visual phenomenon of combustion in full color. It is designed primarily to be used in parallel with, and supplement existing combustion textbooks that are usually in black and white, making it a challenge to visualize such a graphic phenomenon. Each image includes a description of how it was generated, which is detailed enough for the expert but simple enough for the novice. Processes range from small scale academic flames up to full scale industrial flames under a wide range of conditions such as low and normal gravity, atmospheric to high pressures, actual and simulated flames, and controlled and uncontrolled flames. Containing over 500 color images, with over 230 contributors from over 75 organizations, this volume is a valuable asset for experts and novices alike.
Download or read book Sixth International Microgravity Combustion Workshop written by and published by . This book was released on 2001 with total page 490 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Microgravity Combustion written by Howard D. Ross and published by Elsevier. This book was released on 2001-09-03 with total page 601 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides an introduction to understanding combustion, the burning of a substance that produces heat and often light, in microgravity environments-i.e., environments with very low gravity such as outer space. Readers are presented with a compilation of worldwide findings from fifteen years of research and experimental tests in various low-gravity environments, including drop towers, aircraft, and space.Microgravity Combustion is unique in that no other book reviews low- gravity combustion research in such a comprehensive manner. It provides an excellent introduction for those researching in the fields of combustion, aerospace, and fluid and thermal sciences. * An introduction to the progress made in understanding combustion in a microgravity environment* Experimental, theoretical and computational findings of current combustion research* Tutorial concepts, such as scaling analysis* Worldwide microgravity research findings
Download or read book Comparison of Flame Spreading Over Thin Flat Surfaces in Normal Gravity and Weightlessness in an Oxygen Environment written by Charles R. Adracchio and published by . This book was released on 1970 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effect of Oxygen Concentration on Flame Spread Over Thin Fuels in Different Regimes written by and published by . This book was released on 2018 with total page 70 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this research is to investigate how oxygen concentration, opposed flow velocity and thickness of a thin PMMA fuel affect the flame spread rate and flame extinction in microgravity. The flame spread rate increases with an increase in oxygen concentration. The critical oxygen level, which is the minimum concentration for a flame to spread, is inversely related to the fuel thickness. For fuel thickness above and below a critical thickness, the flame spread rate increases and decreases with a decrease in fuel thickness, respectively. Also, an unexpected extinction is discovered. The critical fuel thickness is inversely related to the opposed flow velocity. The flame spread rate decreases when the opposed flow velocity decreases. Unexpected extinction is discovered when oxygen level is low and opposed flow is absent or weak. The simulation results are consistent with the available experimental results obtained by NASA. For a quiescent environment in microgravity, the critical oxygen level increases with the fuel thickness while the critical oxygen level decreases with the fuel thickness for environments with an opposed flow. The research on how a flame extinguishes reveals that the flame temperature in the anomaly region is lower than the flame temperature in the normal region. A flame extinguishes when the percentage surface radiation loss, which is the ratio of the surface radiation loss to heat generated from combustion, is higher than 45% with an opposed flow and 48% in quiescent environment.
Download or read book Unsteady Flame Spread Over Thin Solid Fuels in a Quiescent Microgravity Environment written by Prashant Attibele Ramachandra and published by . This book was released on 1995 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Progress in Scale Modeling Volume II written by Kozo Saito and published by Springer. This book was released on 2014-11-17 with total page 315 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume thoroughly covers scale modeling and serves as the definitive source of information on scale modeling as a powerful simplifying and clarifying tool used by scientists and engineers across many disciplines. The bookelucidates techniques used when it would be too expensive, or too difficult, to test a system of interest in the field. Topics addressed in the current edition include scale modeling to study weather systems, diffusion of pollution in air or water, chemical process in 3-D turbulent flow, multiphase combustion, flame propagation, biological systems, behavior of materials at nano- and micro-scales, and many more. This is an ideal book for students, both graduate and undergraduate, as well as engineers and scientists interested in the latest developments in scale modeling. This book also: Enables readers to evaluate essential and salient aspects of profoundly complex systems, mechanisms, and phenomena at scale Offers engineers and designers a new point of view, liberating creative and innovative ideas and solutions Serves the widest range of readers across the engineering disciplines and in science and medicine
Download or read book Flame Spread in Confined Spaces written by Yanjun Li and published by . This book was released on 2021 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fire behaviors can be significantly different in confined spaces compared with in an open space. Evidence has shown that when subjected to flow confinement, flame can be stronger and spread faster over solid materials. This raises fire safety concern in confined spaces both on earth (e.g., tunnels, building structures) and in space (e.g., space vehicle). To address this concern and to advance understanding of the fire dynamics in confined environments, concurrent-flow flame spread over solid combustibles are investigated in microgravity aboard the International Space Station (ISS). Two types of solid fuel, thin cotton blend fabric (SIABL) and 1 mm thick PMMA slabs are burned in a small flow duct. To effectively reduce the space for flame growth, flow baffles are mounted parallel to the sample. Three different types of baffles are used to alter the radiative boundary conditions of the space that the flame resides: transparent, black, and reflective. By configurating sample/baffles in different ways, three burning scenarios are achieved and examined: double-sided, single-sided, and parallel burning samples. For each burning scenario, confinement levels (i.e., sample-baffle distance) are varied. In addition, the imposed flow speed is also varied to investigate its interplay with the confinement level. Through this, a rich dataset of flame spread is obtained. Different natures of flame spread (i.e., steady state, accelerating flame growth, and flame quenching) are observed when confined conditions vary. Flame characteristics (e.g., spread rate, flame length, flame shape) are also compared between different confined environments. To fully understand the experiment results, an inhouse three-dimensional transient Computational Fluid Dynamics (CFD) combustion model is utilized to conduct the numerical study. The model is first used to simulate the exact geometry of the ISS experiment. The effects of the confinement on solid burning behaviors observed in the experiments are successfully replicated by the numerical model. The model is then used to conduct parametric studies on the confinement levels and radiative reflection from surrounding walls. Through this, detailed profiles of the gas and solid phases are obtained. These include gas temperature, reaction rate contour, and heat fluxes on the sample surface. These profiles are compared between different cases and are used to help explain the burning behaviors observed in the ISS experiments.
Download or read book Upward Flame Spread Over Thin Solids in Partial Gravity written by Ioan I. Feier and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Experimental Upward Flame Spread Over Thin Solids in Partial Gravity written by Ioan I. Feier and published by . This book was released on 2001 with total page 266 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Gravity effects on flame spreading over solid surfaces written by Charles R. Andracchio and published by . This book was released on 1976 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fifth International Microgravity Combustion Workshop written by and published by . This book was released on 1999 with total page 552 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Flame Spread Experiments in a Simulated Microgravity Environment Using a Couette Flow Apparatus written by Karen Woun-Tein Hung and published by . This book was released on 2012 with total page 65 pages. Available in PDF, EPUB and Kindle. Book excerpt: A Couette Flow Apparatus (CFA) was developed to study the effect of a linear velocity gradient on a flame spreading in opposed flow. This apparatus also tests the flammability of materials in a simulated microgravity flow environment. It is a channel with a rectangular cross section that produces a linear air velocity profile above a fuel sample to mimic the boundary layer velocity profile encountered by a flame in an actual microgravity fire. Similar apparatuses have been used to test materials using a parabolic velocity profile, but the purpose of this research is to determine whether or not using a linear velocity profile above the fuel surface produces different results. Simulated microgravity conditions were achieved by minimizing the space above and below the flame to reduce buoyant flow. The apparatus consists of a fixed bottom plate, two side walls, and a moving belt at the top to drive the flow. The belt is made of a Teflon-coated material to withstand the high temperature of the flame since they are in close contact. The side walls and the base plate contain sections of quartz windows so that images and videos could be recorded to show the flame behavior. First, the non-reacting flow was studied. Air velocity measurements were made using hot wire anemometers to determine the velocity profile vertically in the channel. Linear velocity profiles in the channel were not attained until after a fan was added to the outlet to help pull air through; the belt alone was not found to be sufficient. The fan speed was determined by first setting the belt speed and then adjusting the fan speed so that the velocity in the vertical center of the channel was half of the belt speed. The theoretical 2-dimensional flow field was derived analytically by solving the Navier-Stokes equation. The theory predicts that a fan is only necessary to obtain a linear air velocity profile for a smaller width-to-height ratio than what was actually found in the laboratory. The reason for this disagreement is the subject of further research being conducted by another graduate student. It was found that channel is wide enough so that the flow profile is flat over the entire width of the fuel sample. For the combustion tests, the flame speed was tracked using the videos taken through the quartz windows and Spotlight software to obtain flame spread rate. The belt velocity and channel height were varied from 8 to 65 cm/s and 4 to 11 mm, respectively, to study their effect on flame spread. Combustion results indicate that the flame spread rates in the CFA are consistently lower than the spread rates in a traditional Narrow Channel Apparatus due to the flame experiencing more heat loss to the moving boundary of the CFA. The flame spread rates were plotted against average flow velocity for both channels, with peak spread rates occurring at an average flow velocity of around 13-15 cm/s for a 5 mm gap height. Results for the CFA were also plotted against velocity gradient.
Download or read book Transport Effects on Flame Spread Over Thick Solid Fuel Beds in Microgravity and Earth Gravity Environments written by Youngjin Son and published by . This book was released on 2004 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt:
