Download or read book Experiments and Modeling of Multi component Fuel Behavior in Combustion written by Peter R. Solomon and published by . This book was released on 1986 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Experiments and Modeling of Multi Component Fuel Behavior in Combustion written by Peter R. Solomon and published by . This book was released on 1984 with total page 63 pages. Available in PDF, EPUB and Kindle. Book excerpt: An important Air Force objective is to develop technology to allow the utilization of aviation fuels with a broader range of properties including lower hydrogen content and higher aromaticity. The objectives of this program are to develop a data base and modeling capabilities to relate vaporization, pyrolysis, and soot formation to the properties of the fuel, the atomizer and combustion conditions. The benefits of reduced soot in jet engines are significant: increased life, improved reliability of combustor liners and reduced pollution. In addition, reduction of the IR emission from military jet engines is important for lowering an aircraft's visibility for tracking and targeting.
Download or read book Modeling Combustion of Multicomponent Fuel Droplets written by Kannan Vittilapuram Subramanian and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The quasi-steady, spherically symmetric combustion of multicomponent isolated fuel droplets has been modeled using modified Shvab-Zeldovich variable mechanism. Newly developed modified Shvab-Zeldovich equations have been used to describe the gas phase reactions. Vapor-liquid equilibrium model has been applied to describe the phase change at the droplet surface. Constant gas phase specific heats are assumed. The liquid phase is assumed to be of uniform composition and temperature. Radiative heat transfer between the droplet and surroundings is neglected. The results of evaporation of gasoline with discrete composition of hydrocarbons have been presented. The evaporation rates seem to follow the pattern of volatility differentials. The evaporation rate constant was obtained as 0.344mm2/sec which compared well with the unsteady results of Reitz et al. The total evaporation time of the droplet at an ambience of 1000K was estimated to be around 0.63 seconds. Next, the results of evaporation of representative diesel fuels have been compared with previously reported experimental data. The previous experiments showed sufficient liquid phase diffusional resistance in the droplet. Numerical results are consistent with the qualitative behavior of the experiments. The quantitative deviation during the vaporization process can be attributed to the diffusion time inside the droplet which is unaccounted for in the model. Transient evaporation results have also been presented for the representative diesel droplets. The droplet temperature profile indicates that the droplet temperature does not reach an instantaneous steady state as in the case of single-component evaporation. To perform similar combustion calculations for multicomponent fuel droplets, no simple model existed prior to this work. Accordingly, a new simplified approximate mechanism for multicomponent combustion of fuel droplets has been developed and validated against several independent data sets. The new mechanism is simple enough to be used for computational studies of multicomponent droplets. The new modified Shvab-Zeldovich mechanism for multicomponent droplet combustion has been used to model the combustion characteristics of a binary alcohol-alkane droplet and validated against experimental data. Burn rate for the binary droplet of octanol-undecane was estimated to be 1.17mm2/sec in good concurrence with the experimental value of 0.952mm2/sec obtained by Law and Law. The model has then been used to evaluate the combustion characteristics of diesel fuels assuming only gas phase reactions. Flame sheet approximation has been invoked in the formulation of the model.
Download or read book Enclosure Fire Dynamics written by Bjorn Karlsson and published by CRC Press. This book was released on 1999-09-28 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt: The increasing complexity of technological solutions to both fire safety design issues and fire safety regulations demand higher levels of training and continuing education for fire protection engineers. Historical precedents on how to deal with fire hazards in new or unusual buildings are seldom available, and new performance-based building codes
Download or read book Modeling of Multicomponent Fuel Vaporization in Internal Combustion Engines written by Yangbing Zeng and published by . This book was released on 2000 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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:
Download or read book A COMBUSTION MODEL FOR MULTI COMPONENT FUELS BASED ON RELATIVE REACTIVITY AND MOLECULAR STRUCTURE written by and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract : A reliable multi-component surrogate fuel model needs to be able to represent both physical properties and chemical kinetics of a real fuel. However, enhancing the fidelity of a model with detailed description of physical and chemical behavior of all fuel components found in real fuels is limited by the prohibitive computational load to calculate the combustion chemistry of the fuel. Hence, it is desirable to achieve computational efficiency by reducing the number of chemical surrogates at the minimum expense of prediction accuracy. The objective of this work is to develop a model that can simulate the oxidation of multi-component fuels by representing the ignition characteristics of physical surrogate components with fewer chemical surrogates and achieve both computational efficiency and prediction accuracy. The main advantage of the model, called the Reactivity-Adjustment (ReAd) combustion model, is to accurately predict the reactivity of the physical surrogate components that the reaction mechanisms of which are not included in the reaction kinetics model employed in the simulation. The reactivity variation of local mixtures with different compositions is modeled by adjusting the reaction rate constants of selected control-reactions in the reaction mechanism of the representative chemical surrogates. An initial version of the model has been developed employing a single chemical surrogate to represent the combustion of diesel fuel which is modeled as multiple surrogate components to capture the physical properties of the real fuel. The model was extended to consider two more chemical surrogate components to represent the ignition characteristics of other chemical families than n-alkanes. This enabled to avoid the excessive adjustment of reaction rate constants that were necessary when a single chemical surrogate is used to represent the oxidation kinetics of entire multi-component fuels. The model was extensively tested for simulating oxidation processes of many fuels with a variety of fuel reactivity and in various combustion regimes. The results demonstrated that excellent accuracy of the ignition/combustion prediction was achieved while ensuring computational efficiency.
Download or read book Energy Research Abstracts written by and published by . This book was released on 1991-10 with total page 582 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Generating Reduced Mechanisms for Realistic Multi component Fuel Combustion written by Lara Backer and published by . This book was released on 2019 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt: The race to reduce pollutant emissions from hydrocarbon combustion while simultaneously increasing fuel efficiency and optimizing engine performance calls for the use of numerical simulations in parallel with, or in lieu of, expensive and time-consuming experiments. To explore the efficacy of emerging alternative fuels and additives in numerical simulations and to predict the effects of the fuel description on emissions, the fuel should be treated as one of the optimization parameters. This necessitates an accurate and detailed description of the fuel and its breakdown, as combustion kinetics are exceedingly dependent on fuel constituents. However, the combustion of even a single fuel component can involve hundreds of species and thousands of reactions, requiring prohibitively high CPU times for realistic simulations of complex fuels with detailed chemistry. An advantageous strategy to combat this difficulty is to employ reduced-order modeling by replacing the realistic fuel blend with a simplified description called a surrogate, in tandem with reducing the chemical kinetic mechanism. In recent years, a component library framework has been proposed to facilitate the creation of reduced-order models for practical applications. The idea is that chemical models for single-component fuels can be reduced separately and combined at-will to represent any surrogate blend of interest. However, this approach fails when individual fuel molecules have significant non-linear interactions with one another during combustion, or when the prediction of pollutant formation is of interest, since the kinetics involved strongly depend on the details of the multi-component fuel mixture. In this work, two new strategies are presented to automatically facilitate the generation of compact, reduced-order models for multi-component fuels. The first addresses the drawbacks of the component library framework by efficiently allowing for the automatic creation of reduced fuel component oxidation mechanisms and the addition of secondary pathways of interest onto existing component library modules, directly at the reduced level. The second generates a compact description of multi-component fuel decomposition chemistry, significantly reducing the computational cost of simulating fuels with numerous constituents. Reduced-order models created with these techniques are shown to reproduce the behavior of detailed kinetic models reasonably well. Subsequent studies leverage the strategies presented here to produce reduced kinetic mechanisms for multi-component fuel chemistry. A preliminary analysis highlights relevant combustion regimes and useful canonical problems to consider when reducing models for turbulent combustion applications. Results from this analysis are used to guide the creation of a compact reduced-order model for jet fuel.
Download or read book Combustion written by J. Warnatz and published by Springer Science & Business Media. This book was released on 2006-08-18 with total page 389 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a rigorous treatment of the coupling of chemical reactions and fluid flow. Combustion-specific topics of chemistry and fluid mechanics are considered and tools described for the simulation of combustion processes. This edition is completely restructured. Mathematical Formulae and derivations as well as the space-consuming reaction mechanisms have been replaced from the text to appendix. A new chapter discusses the impact of combustion processes on the atmosphere, the chapter on auto-ignition is extended to combustion in Otto- and Diesel-engines, and the chapters on heterogeneous combustion and on soot formation are heavily revised.
Download or read book Automotive Fuels Reference Book written by Paul Richards and published by SAE International. This book was released on 2014-03-05 with total page 870 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first two editions of this title, published by SAE International in 1990 and 1995, have been best-selling definitive references for those needing technical information about automotive fuels. This long-awaited new edition has been thoroughly revised and updated, yet retains the original fundamental fuels information that readers find so useful. This book is written for those with an interest in or a need to understand automotive fuels. Because automotive fuels can no longer be developed in isolation from the engines that will convert the fuel into the power necessary to drive our automobiles, knowledge of automotive fuels will also be essential to those working with automotive engines. Small quantities of fuel additives increasingly play an important role in bridging the gap that often exists between fuel that can easily be produced and fuel that is needed by the ever-more sophisticated automotive engine. This book pulls together in a single, extensively referenced volume, the three different but related topics of automotive fuels, fuel additives, and engines, and shows how all three areas work together. It includes a brief history of automotive fuels development, followed by chapters on automotive fuels manufacture from crude oil and other fossil sources. One chapter is dedicated to the manufacture of automotive fuels and fuel blending components from renewable sources. The safe handling, transport, and storage of fuels, from all sources, are covered. New combustion systems to achieve reduced emissions and increased efficiency are discussed, and the way in which the fuels’ physical and chemical characteristics affect these combustion processes and the emissions produced are included. There is also discussion on engine fuel system development and how these different systems affect the corresponding fuel requirements. Because the book is for a global market, fuel system technologies that only exist in the legacy fleet in some markets are included. The way in which fuel requirements are developed and specified is discussed. This covers test methods from simple laboratory bench tests, through engine testing, and long-term test procedures.
Download or read book Study of Multi component Fuel Premixed Combustion Using Direct Numerical Simulation written by Zacharias M. Nikolaou and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
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.
Download or read book Experiments and Numerical Simulations of Turbulent Combustion of Diluted Sprays written by Bart Merci and published by Springer Science & Business Media. This book was released on 2014-03-27 with total page 167 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book reflects the results of the 2nd and 3rd International Workshops on Turbulent Spray Combustion. The focus is on progress in experiments and numerical simulations for two-phase flows, with emphasis on spray combustion. Knowledge of the dominant phenomena and their interactions allows development of predictive models and their use in combustor and gas turbine design. Experts and young researchers present the state-of-the-art results, report on the latest developments and exchange ideas in the areas of experiments, modelling and simulation of reactive multiphase flows. The first chapter reflects on flame structure, auto-ignition and atomization with reference to well-characterized burners, to be implemented by modellers with relative ease. The second chapter presents an overview of first simulation results on target test cases, developed at the occasion of the 1st International Workshop on Turbulent Spray Combustion. In the third chapter, evaporation rate modelling aspects are covered, while the fourth chapter deals with evaporation effects in the context of flamelet models. In chapter five, LES simulation results are discussed for variable fuel and mass loading. The final chapter discusses PDF modelling of turbulent spray combustion. In short, the contributions in this book are highly valuable for the research community in this field, providing in-depth insight into some of the many aspects of dilute turbulent spray combustion.
Download or read book Microgravity Fluid Mechanics written by Hans J. Rath and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 595 pages. Available in PDF, EPUB and Kindle. Book excerpt: Substantial progress has been made in the field of fluid mechanics under compensated gravity effects (microgravity). The main task of this disciplinehas evolved tremendously. Starting out with the aim of providing assistance in describing flow problems in other microgravity sciences, microgravityfluid mechanics has itself now become acknowledge as a powerful means of research. The IUTAM Symposium on Microgravity Fluid Mechanics has pro- vided the long-awaited forum for scientists from 15 coun- tries to discuss and concretize the "state-of-the-art" in this discipline. The main themes treated are: Interface Phe- nomena, Convective Processes; Marangoni effects, Solidifica- tion, Combustion, Physico-Chemical Processes, Multiphase Phenomena, Residual Acceleration effects, Fluid Handling and Non-Newtonian Flows.
Download or read book Investigation of the Combustion Characteristics of Fuel Droplet Arrays Final Technical Report written by and published by . This book was released on 1980 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The program was directed at establishing the nature and extent of droplet/droplet interaction and the multicomponent nature of real fuels on the ignition and combustion characteristics of spray flames. A unique free-droplet combustion experiment provided the present investigation with a well-controlled simulation of spray combustion. Various theoretical models were used. Experimental observations indicate that ignition delay times increase sharply by about three-fold when droplet spacings are reduced to less than five droplet diameters. Results of theoretical predictions indicate that as droplet spacing is made smaller, the effect of droplet/droplet interaction on ignition delay becomes increasingly more pronounced for small droplets, low gas phase temperatures, and fuels of low volatility. Although this result suggests that ignition of heavy grades of alternative liquid fuels will be inhibited in dense sprays, other theoretical and experimental results indicate that the addition of a small quantity of a volatile component to a heavy fuel shortens ignition times substantially. Observed burning times show a gradual, but substantial, increase as a result of droplet/droplet interaction; as droplet spacing is decreased from 40 to 5 diameters, burning times increase by about 60%. A compilation of data for an extensive range of experimental parameters show universally that the amount by which droplet/droplet interaction increases burning times depends only on droplet spacing and not on the fuel type or the ambient conditions. Burning times of multicomponent fuel droplets are found to be weighted heavily toward the burning time for the least volatile component. Theoretical predictions demonstrate that this independence of burning times on the initial fuel mixture proportions can be ascribed to liquid phase mass diffusion limitations.
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
