Author: Dongyao WangPublisher:
ISBN:
Category :
Languages : en
Pages : 308
Book Description
Modeling of Multi-component Fuel Vaporization for Spray Simulations Using Continuous Thermodynamics
Author: Dongyao WangModeling of Multicomponent Fuels with Application to Sprays and Simulation of Diesel Engine Cold Start
Author: Andreas M. LippertPublisher:
ISBN:
Category : Diesel fuels
Languages : en
Pages : 728
Book Description
May 1999
Modeling Engine Spray and Combustion Processes
Author: Gunnar StieschPublisher: Springer Science & Business Media
ISBN: 3662087901
Category : Computers
Languages : en
Pages : 293
Book Description
The utilization of mathematical models to numerically describe the performance of internal combustion engines is of great significance in the development of new and improved engines. Today, such simulation models can already be viewed as standard tools, and their importance is likely to increase further as available com puter power is expected to increase and the predictive quality of the models is constantly enhanced. This book describes and discusses the most widely used mathematical models for in-cylinder spray and combustion processes, which are the most important subprocesses affecting engine fuel consumption and pollutant emissions. The relevant thermodynamic, fluid dynamic and chemical principles are summarized, and then the application of these principles to the in-cylinder processes is ex plained. Different modeling approaches for the each subprocesses are compared and discussed with respect to the governing model assumptions and simplifica tions. Conclusions are drawn as to which model approach is appropriate for a specific type of problem in the development process of an engine. Hence, this book may serve both as a graduate level textbook for combustion engineering stu dents and as a reference for professionals employed in the field of combustion en gine modeling. The research necessary for this book was carried out during my employment as a postdoctoral scientist at the Institute of Technical Combustion (ITV) at the Uni versity of Hannover, Germany and at the Engine Research Center (ERC) at the University of Wisconsin-Madison, USA.
Heating and Evaporation of Multi-Component Fuel Droplets
Author: Mansour Al QubeissiPublisher: BoD – Books on Demand
ISBN: 3955380238
Category : Technology & Engineering
Languages : en
Pages : 302
Book Description
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.
Droplets and Sprays: Simple Models of Complex Processes
Author: Sergei S. SazhinPublisher: Springer Nature
ISBN: 3030997464
Category : Technology & Engineering
Languages : en
Pages : 603
Book Description
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.
Modeling Multicomponent Fuel Sprays in Engines with Application to Diesel Cold-starting
Author: Nabil S. AyoubA Continuous Thermodynamics Model for Multicomponent Droplet Vaporization
Author: Jihane TamimPublisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
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.
Modelling Two-phase Flow and Transport Effects of Multi-component Fuels
Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Three novel multicomponent fuel spray droplet evaporation models are developed by employing the theory of continuous thermodynamics(CT) with the aim of applying them in the design and analysis of various energy conversion devices such as, aircraft jet engines, liquid-fuel rocket engines, diesel engines, and industrial furnaces. The CT methodology seeks to represent complex mixtures - for example, aviation kerosene or JP8 that typically comprise blends of a large number of chemical compounds by using probability distribution functions (PDFs). The components of JP8, which is constituted by the homologous series of paraffin, naphthene, and aromatic hydrocarbons; are each represented by the Pearson-Shultz type three-parameter gamma PDF, where the three (shape, scale, and origin) parameters characterise changes in the mixture composition. The phase transition of the liquid droplet due to evaporation is modelled using both low-pressure (LP) and high-pressure (HP) vapour-liquid equilibrium (VLE) models employing various mixing and combining rules by applying a general cubic equation of state (CEOS). Interestingly enough, the phase transition of the liquid fuel into vapour mixture is characterised by a change in the PDF scale parameter alone. Once the description of the fuel mixture is complete, the traditional species and energy transport equations both for the liquid and vapour phases respectively, are re-written using the composition PDF moments under Lagrangian and Eulerian frameworks. In order to solve the governing equations for the three droplet evaporation models, which characteristically involve phase change and a moving interface, a novel fully Adaptive Method Of Lines using B-Spline Collocation (AMOLBSC) is developed. The models are tested at various pressures, temperatures and convective conditions, including at a lean, premixed, prevaporised (LPP) combustor operating condition. In general, the computational results at an ambient pressure close to atmospheric sho.
Drop Heating and Evaporation: Analytical Solutions in Curvilinear Coordinate Systems
Author: Gianpietro Elvio CossaliPublisher: Springer Nature
ISBN: 3030492745
Category : Technology & Engineering
Languages : en
Pages : 403
Book Description
This book describes analytical methods for modelling drop evaporation, providing the mathematical tools needed in order to generalise transport and constitutive equations and to find analytical solutions in curvilinear coordinate systems. Transport phenomena in gas mixtures are treated in considerable detail, and the basics of differential geometry are introduced in order to describe interface-related transport phenomena. One chapter is solely devoted to the description of sixteen different orthogonal curvilinear coordinate systems, reporting explicitly on the forms of their differential operators (gradient, divergent, curl, Laplacian) and transformation matrices. The book is intended to guide the reader from mathematics, to physical descriptions, and ultimately to engineering applications, in order to demonstrate the effectiveness of applied mathematics when properly adapted to the real world. Though the book primarily addresses the needs of engineering researchers, it will also benefit graduate students.
Modelling Diesel Combustion
Author: P. A. LakshminarayananPublisher: Springer Nature
ISBN: 981166742X
Category : Technology & Engineering
Languages : en
Pages : 419
Book Description
This book comprehensively discusses diesel combustion phenomena like ignition delay, fuel-air mixing, rate of heat release, and emissions of smoke, particulate and nitric oxide. It enables quantitative evaluation of these important phenomena and parameters. Most importantly, it attempts to model them with constants that are independent of engine types and hence they could be applied by the engineers and researchers for a general engine. This book emphasizes the importance of the spray at the wall in precisely describing the heat release and emissions for most of the engines on and off-road. It gives models for heat release and emissions. Every model is thoroughly validated by detailed experiments using a broad range of engines. The book describes an elegant quasi-one-dimensional model for heat release in diesel engines with single as well as multiple injections. The book describes how the two aspects, namely, fuel injection rate and the diameter of the combustion bowl in the piston, have enabled meeting advanced emission, noise, and performance standards. The book also discusses the topics of computational fluid dynamics encompassing RANS and LES models of turbulence. Given the contents, this book will be useful for students, researchers and professionals working in the area of vehicle engineering and engine technology. This book will also be a good professional book for practising engineers in the field of combustion engines and automotive engineering.