Download or read book Structure and Extinction of Spherical Diffusion Flames in Microgravity written by Karl J. Santa and published by . This book was released on 2006 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Structure of Spherical Diffusion Flames in Microgravity written by Kristine Renee Mills and published by . This book was released on 1998 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Assuming that the activation energy is large, we develop an asymptotic theory that treats the flame as a surface, on either side of which the chemical reaction rate is negligibly small. By examining the flame structure, we derive an explicit dependence of the combustion parameters on the flame temperature and reactants' leakage through the flame. A new element of this work is that the Lewis numbers associated with the fuel and oxidant are kept arbitrary, and that additional factors influencing the flame structure are included.

Download or read book Computational Simulation of Spherical Diffusion Flame Dynamics and Extinction in Microgravity written by Tianying Xia and published by . This book was released on 2015 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book On the Structure and Stability of Diffusion Flames written by Sally Ann Cheatham and published by . This book was released on 1997 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Diffusion flames are flames in which fuel and oxidant, initially separate, come together to react chemically in a relatively thin combustion zone. Asymptotic methods, supplemented by numerical computation, are used to analyze the structure and dynamical properties of such flames. Attention is first focused on diffusion flames in arbitrary fluid flows for general fuel and oxidant Lewis numbers, in which the combustion is complete or nearly complete. Thus the limit of large Damkohler number and large activation energy is considered. The resulting mathematical formulation consists of a free boundary problem, with the flame as the free boundary. Such a treatment greatly simplifies the governing system of equations, and provides a framework for the analysis of the flame structure as well as its dynamical properties. The stability of a planar flame is next considered, with attention focused on diffusional-thermal effects. A dispersion relation is obtained, which relates the growth parameter and wavenumber of disturbances to the fuel and oxidant Lewis numbers, supply temperatures, and supply concentrations. Analysis of the dispersion relations indicates that instability corresponding to cellularity of the flame may occur for lean flames under near extinction conditions when the Lewis numbers of fuel and oxidant are sufficiently low. The asymptotic model is also used to identify conditions under which flame extinction occurs. In particular, the burning characteristics of a dilute spray diffusion flame have been examined. The presence of fuel droplets in the fuel supply is shown to alter the extinction characteristics of the flame. The onset of oscillations in the spherical diffusion flame surrounding a fuel droplet is also considered. Motivated by recent microgravity candle flame experiments, the constraint of a weak oxidant environment is imposed. A linear stability analysis indicates that oscillations may indeed result when radiative heat losses and the Lewis numbers of fuel and oxidant are sufficiently large. Estimates for the critical conditions are given, along with a prediction of the resulting frequency of oscillation. A weakly non-linear analysis is then used to more fully investigate the transition to an oscillatory burning state.

Download or read book Chemiluminescent Flame Structure Aerodynamic Scaling and Oscillating Extinction of Weakly Buoyant Nearly Spherical Diffusion Flames written by Sean Won S. Yoo and published by . This book was released on 2002 with total page 258 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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:

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 Buoyant Low Stretch Stagnation Point Diffusion Flames Over a Solid Fuel written by Sandra Lee Olson and published by . This book was released on 1997 with total page 430 pages. Available in PDF, EPUB and Kindle. Book excerpt: Focuses on the flame structure and extinction characteristics of diffusion flames in microgravity. A normal gravity low-stretch diffusion flame is generated by means of a cylindrical PMMA (polymethylmethacrylate) sample of varying large radii. Solid-phase conductive heat loss is varied by modifying the back surface boundary conditions on the samples. Burning rates, flame thickness and standoff distance, temperature profiles in the solid and gas, and radiative loss from the system are measured.

Download or read book Microgravity Combustion Research 1999 Program and Results written by and published by . This book was released on 1999 with total page 72 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 Second International Microgravity Combustion Workshop written by and published by . This book was released on 1993 with total page 402 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Computational Study on Oscillatory Extinction of Spherical Diffusion Flames written by E. W. Christiansen 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 On the Structure and Dynamics of Stationary and Rotating Spherical Diffusion Flames written by Sean Won S. Yoo and published by . This book was released on 2006 with total page 556 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Instabilities of Spreading Diffusion Flames in Microgravity and the Design and Construction of a Hele shaw Apparatus that Produces Flames in the Near Extinction Limit Regime Under Simulated Low Gravity Conditions written by Lisa Marie Oravecz and published by . This book was released on 2001 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Observations of Methane and Ethylene Diffusion Flames Stabilized Around a Blowing Porous Sphere Under Microgravity Conditions written by Arvind Atreya and published by . This book was released on 1994 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Microgravity Burner generated Spherical Diffusion Flames written by S. D. Tse and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Microgravity Combustion Science 1995 Program Update written by and published by . This book was released on 1995 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt: