Download or read book Modelling of the Multicomponent Droplet Vaporization written by Virginel Bodoc and published by . This book was released on 2011 with total page 54 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this thesis was to study the vaporization of a multicomponent spray with both experimental and numerical approaches. To achieve this objective, the effort was guided in two directions. Firstly, an experimental database has been created using different optical measurement techniques. A special attention was focused onto the application of Global Rainbow Refractometry (GRR), used for the measurement of droplets temperature. Secondly, numerical simulations were performed for mono and bi-component sprays in evaporation. In the first part of this study, experimental and numerical tests were carried out on a polydisperse nonconfined and cooling spray. This configuration was adopted because it allows the study of the vaporization with a reduced influence from the gaseous phase. For a bi-component liquid, the effect of the composition variation on the GRR measurements was analysed within a coupling between the experimental technique and the numerical simulation. In the second part, experimental investigations and numerical simulation were performed for a more complex configuration that consists in a spray evolving in a heated and confined medium. The gaseous phase was computed with a LES approach while the dispersed phase, always mono-component, was solved with a Lagrangian tracking approach . The unsteady nature of the flow was demonstrated and the interest of the GRR technique for the droplets temperature measurement was proved.
Download or read book A Model for Multicomponent Droplet Vaporization at High Ambient Pressures written by J. D. Jin and published by . This book was released on 1985 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Continuous Thermodynamics Model for Multicomponent Droplet Vaporization written by and published by . This book was released on 1997 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Model of Multicomponent Droplet Evaporation with Liquid Phase Reactions written by Yusuf Sezen and published by . This book was released on 1986 with total page 452 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Continuous Thermodynamics Model for Multicomponent Droplet Vaporization written by Jihane Tamim and published by . This book was released on 1997 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: For mixtures containing many components, as in the case of commercial fuels and polymer solutions for example, it is practically impossible to have a complete listing of all the components. A method known as continuous thermodynamics has recently been developed for use when dealing with such mixtures. Continuous thermodynamics describes the composition of the mixture by a probability density function with respect to one or more variable, such as molecular mass, boiling point or any other physical property. This method is used here to study the vaporization of multicomponent fuel droplets. Liquid droplet vaporization plays an important role in the formation of the fuel/air mixture necessary for combustion, and the fuel composition has an effect on the performance of combustion equipment such as Diesel engines. Transport equations are developed, which describe species diffusion in terms of the parameters of the distribution function. These equations are developed for "fuel" vapour as a whole and for the mean and second moment of the distribution. A continuous thermodynamics form of the energy equation is also developed. These general equations are then applied to the vaporizing droplet problem. A gamma distribution function, with molecular mass as the characterizing variable has been chosen. The transport equations in continuous form have been incorporated into a finite difference model of droplet vaporization. Physical property correlations have also been developed in terms of the characterizing variable chosen and integrated in the model. The numerical solution of these equations and the equations of conservation of mass and species at the droplet surface gives the droplet vaporization rate, the mixture composition field in the vapour phase surrounding the droplet and the change of the liquid composition with time.
Download or read book Chemical Kinetics in Combustion and Reactive Flows Modeling Tools and Applications written by V. I. Naoumov and published by Cambridge University Press. This book was released on 2019-08-22 with total page 449 pages. Available in PDF, EPUB and Kindle. Book excerpt: Introduces advanced mathematical tools for the modeling, simulation, and analysis of chemical non-equilibrium phenomena in combustion and flows, following a detailed explanation of the basics of thermodynamics and chemical kinetics of reactive mixtures. Researchers, practitioners, lecturers, and graduate students will find this work valuable.
Download or read book Handbook of Physical Properties of Liquids and Gases written by N.B. Vargaftik and published by Springer. This book was released on 2014-04-13 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides numerical data on physical and thermodynamic properties of a large number of elements and compounds. SI units are used throughout, and in addition, an adequate set of conversion tables is included. This volume will be a valuable source of reference for physical chemists and chemical engineers.
Download or read book Droplets and Sprays written by Sergei Sazhin and published by Springer. This book was released on 2014-05-19 with total page 345 pages. Available in PDF, EPUB and Kindle. Book excerpt: Providing a clear and systematic description of droplets and spray dynamic models, this book maximises reader insight into the underlying physics of the processes involved, outlines the development of new physical and mathematical models and broadens understanding of interactions between the complex physical processes which take place in sprays. Complementing approaches based on the direct application of computational fluid dynamics (CFD), Droplets and Sprays treats both theoretical and practical aspects of internal combustion engine process such as the direct injection of liquid fuel, subcritical heating and evaporation. Including case studies that illustrate the approaches relevance to automotive applications, it is also anticipated that the described models can find use in other areas such as in medicine and environmental science.
Download or read book Multicomponent Droplet Vaporization in a High Temperature Gas written by A. Y. Tong and published by . This book was released on 1984 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Attempts have been made to compare the results of various models with the existing experimental data - no final conclusion can be drawn based on the experimental data.
Download or read book Computer Simulation of the Burning of a Multicomponent Droplet written by Elizabeth Katherine Flatbush and published by . This book was released on 1987 with total page 118 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Heating and Evaporation of Multi Component Fuel Droplets written by Mansour Al Qubeissi and published by BoD – Books on Demand. This book was released on 2015-08-01 with total page 302 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book documents pioneering mathematical models introduced for the simulation of multi-component droplets heating and evaporation processes which are implementable into commercial CFD codes. These models, described as 'multi-dimensional quasi discrete' (MDQD) and 'discrete-component' models, were applied to automotive fuel droplets in experimentally measured internal combustion engine conditions for biodiesel, diesel, and gasoline fuels. For instance, it is shown that the suggested models lead to accurate predictions of temperatures and evaporation times in typical diesel and gasoline engine conditions. Such models have also reduced CPU time about 85% compared with cases when classical approaches are used.
Download or read book Improved Modeling of Drop Vaporization and Combustion in Sprays written by and published by . This book was released on 2001 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this work, multicomponent and single component droplet vaporization characteristics are investigated by employing computational models. It is shown that simplified droplet vaporization models that do not solve temperature gradients or flow within the droplet and do not solve gradients in temperature or species in the immediate surrounding of the droplet are able to reproduce droplet vaporization rates and droplet lifetime with about 15% accuracy compared to detailed models for typical Diesel operating conditions. Under high temperature (> 1200 K) conditions the differences begin to increase. However, it is also shown that under such conditions as well as at even lower temperatures (> 900 K) the vaporization process is mixing limited i.e., the droplet lifetime is not controlling but rather the characteristic time for mixing of ambient air with the vapor phase the liquid, vapor and air are in phase equilibrium. It is shown that droplets are not likely to react the critical state under typical engine conditions. With application to multidimensional spray models as focus, a new model for predicting the outcome of drop collisions has been developed. Such models are important because they predict the drop sizes in the spray following atomization.
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 Fluid Dynamics and Transport of Droplets and Sprays written by W. A. Sirignano and published by Cambridge University Press. This book was released on 2010-01-11 with total page 481 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book discusses the theoretical foundations of spray and droplet applications relevant to the technology for active control of sprays applied to new products and applications, improved product performance, cost reductions, and improved environmental outcomes. It also covers theory related to power and propulsion; materials processing and manufacturing technologies including droplet-based net form processing, coating, and painting; medication; pesticides and insecticides; and other consumer uses.
Download or read book Multi component Droplet Evaporation Model written by Omid Samimi Abianeh and published by . This book was released on 2011 with total page 204 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Droplets and Sprays Simple Models of Complex Processes written by Sergei S. Sazhin and published by Springer Nature. This book was released on 2022-06-28 with total page 603 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book acts as a guide to simple models that describe some of the complex fluid dynamics, heat/mass transfer and combustion processes in droplets and sprays. Attention is focused mainly on the use of classical hydrodynamics, and a combination of kinetic and hydrodynamic models, to analyse the heating and evaporation of mono- and multi-component droplets. The models were developed for cases when small and large numbers of components are present in droplets. Some of these models are used for the prediction of time to puffing/micro-explosion of composite water/fuel droplets — processes that are widely used in combustion devices to stimulate disintegration of relatively large droplets into smaller ones. The predictions of numerical codes based on these models are validated against experimental results where possible. In most of the models, droplets are assumed to be spherical; some preliminary results of the generalisation of these models to the case of non-spherical droplets, approximating them as spheroids, are presented.
Download or read book A Theoretical and Experimental Investigation of Multi phase Interactions in Pure and Multicomponent Droplet Evaporation written by Courtney Leigh Herring Bonuccelli and published by . This book was released on 2006 with total page 181 pages. Available in PDF, EPUB and Kindle. Book excerpt:
