Flow and Combustion in Reciprocating Engines


Book Description

Optimization of combustion processes in automotive engines is a key factor in reducing fuel consumption. This book, written by eminent university and industry researchers, investigates and describes flow and combustion processes in diesel and gasoline engines.













The Influence of In-cylinder Flows on the Flame Kernel Growth in Natural Gas Fuelled Spark Ignition Engines


Book Description

The objective of this work was to determine the influence of in-cylinder flows on the natural gas combustion process in configurations representative of light duty vehicle spark ignition engines. Specifically, the influence of the flow field on the flame kernel development period was of interest. The interactions between the flow field and the combustion process were quantified by correlating characteristic in-cylinder fluid flow and mass burn rate parameters. The fluid motion, flame kernel development and the overall combustion duration were characterised using: (i) a two-component laser Doppler velocimeter for the in-cylinder fluid flow, (ii) a fibre-optic instrumented spark plug for the flame kernel growth rate, and (iii) a piezo-electric pressure transducer for the in-cylinder pressure from which the overall mass burn rate data is obtained. The measurements were made on an individual cycle basis. Results from a single cylinder V6 optical engine are reported. Physical interpretations of: (i) the flow field evolution and (ii) the interactions between the flow field and the natural gas combustion process are presented. The main contributions of this work are through: (i) the application of novel data processing techniques, and (ii) the exploration of the fibre-optic instrumented spark plug as a measurement technique in high swirl engines. For example, the discrete wavelet transform is used to show: (i) the energy cascade process in the non-stationary engine flow field over crank angle phase and frequency; and (ii) how the flow field evolution influences the early stages of the natural gas combustion process. The fibre-optic instrumented spark plug is shown to measure a mass-weighted velocity. Data from the fibre-optic instrumented spark plug data are shown to be biased by the large convection velocities in high swirl engines. This work provides the foundation upon which further investigations into the influence of different in-cylinder flows on the natural gas combustion process in spark ignition engines can be based.




Fuel Economy


Book Description

Concern about the reduced availability and the increased cost of petroleum fuels prompted great efforts in recent years to reduce the fuel consumption of auto mobiles. The ongoing efforts to reduce fuel consumption have addressed many relevant factors, including increased engine performance, reduced friction, use of lightweight materials, and reduced aerodynamic drag. The results of the investigations assessing the various factors affecting fuel economy have been published in journals, conference proceedings, and in company and government reports. This proliferation of technical information makes it difficult for workers to keep abreast of aU developments. The material presented in this book brings together in a single volume much of the relevant materials, summarizes many of the state-of-the-art theories and data, and provides extensive lists of references. Thus, it is hoped that this book will be a useful reference for specialists and practicing engineers interested in the fuel economy of automobiles. J. C. HILLIARD o. S. SPRINGER vii CONTENTS 1. AUTOMOTIVE FUEL ECONOMY David Cole I. Introduction and Background. . . . . . . . . . . . . . . . . . . . . . . . . . . 1 . . . . . . . . . . n. Fuel Economy Factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 A. Engine................................................... 11 B. Drive Train. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 . . . . . . . . . . . . . . C. Vehicle Factors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 . . . . . . . . . . . . . D. Operating Factors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 . . . . . . . . . . . . E. Test Cycles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 . . . . . . . . . . . . . . . . . 2. FUEL ECONOMY AND EMISSIONS J. T. Kummer I. Introduction .................................................. . 35 n. Emission Regulations .......................................... .




Internal Combustion Engines


Book Description

Since the publication of the Second Edition in 2001, there have been considerable advances and developments in the field of internal combustion engines. These include the increased importance of biofuels, new internal combustion processes, more stringent emissions requirements and characterization, and more detailed engine performance modeling, instrumentation, and control. There have also been changes in the instructional methodologies used in the applied thermal sciences that require inclusion in a new edition. These methodologies suggest that an increased focus on applications, examples, problem-based learning, and computation will have a positive effect on learning of the material, both at the novice student, and practicing engineer level. This Third Edition mirrors its predecessor with additional tables, illustrations, photographs, examples, and problems/solutions. All of the software is ‘open source’, so that readers can see how the computations are performed. In addition to additional java applets, there is companion Matlab code, which has become a default computational tool in most mechanical engineering programs.




End-zone Water Injection as a Means of Suppressing Knock in a Spark-ignition Engine


Book Description

Summary: An investigation has been made of the effectiveness of water injection into the combustion end zone of a spark-ignition engine cylinder for the suppression of knock. Pressure-time recoreds obtained show that injection of water at 60° B.T.C. on the compression stroke at a water-fuel ratio of 0.3 rendered M-3 fuel as good as S-3 fuel from an antiknock consideration. The optimum crank angle for injection of water into the end zone was found to be critical. As the injection angle was increased beyond the optimum, the quantity of water required to suppress knock increased to 3.6 water-fuel ratio at 132° B.T.C. The water quantity could not be increased beyond 3.6 water-fuel ration because of injection-pump limitations; however, a further increase in the injection angle up to the earliest angle obtainable, which was 20° A.T.C. on the intake stroke, continuously increased the knock intensity. The engine operating conditions of the tests did not simulate those encountered in flight, especially with regard to the operating speed of 570 rpm. For this reason the results should only be regarded as of theoretical importance until further investigation has been made.




Handbook of Fluid Dynamics


Book Description

Handbook of Fluid Dynamics offers balanced coverage of the three traditional areas of fluid dynamics—theoretical, computational, and experimental—complete with valuable appendices presenting the mathematics of fluid dynamics, tables of dimensionless numbers, and tables of the properties of gases and vapors. Each chapter introduces a different fluid dynamics topic, discusses the pertinent issues, outlines proven techniques for addressing those issues, and supplies useful references for further research. Covering all major aspects of classical and modern fluid dynamics, this fully updated Second Edition: Reflects the latest fluid dynamics research and engineering applications Includes new sections on emerging fields, most notably micro- and nanofluidics Surveys the range of numerical and computational methods used in fluid dynamics analysis and design Expands the scope of a number of contemporary topics by incorporating new experimental methods, more numerical approaches, and additional areas for the application of fluid dynamics Handbook of Fluid Dynamics, Second Edition provides an indispensable resource for professionals entering the field of fluid dynamics. The book also enables experts specialized in areas outside fluid dynamics to become familiar with the field.