Fundamentals of fuel injection and emission in two-stroke engines

Authors:

• Władysław Mitianiec

Abstract

The book includes thirteen chapters devoted to the processes of fuel injection and combustion taking place in a stratified charge in the cylinder of two-stroke engines and references attached at the end of each chapter. In the first two chapters, the categorization of different injection systems in two-stroke engines is presented and each injection system is briefly described. Various theoretical and practical solutions of design of fuelling systems are also described. Chapter 3 gives the mathematical models and describes the spatial movement of the gas in the cylinder and the combustion chamber as well as the most well-known models of turbulence charge. Chapter 4 relates to the behavior of fuel injected into the gaseous medium, including evaporation processes, disintegration, and processes occurring when fuel droplets are in a contact with the wall. The next chapter describes the zero-dimensional model of fuel injection in two-stroke engines with examples of numerical calculations. The sixth chapter is devoted to multi-dimensional models of movement and evaporation of the fuel in a closed gaseous medium (Phoenics and KIVA). The general processes described also take place in other types of engines. Chapter 7 describes a two-zone model of the combustion process and the effect of the geometry of the combustion chamber on the process of flame propagation. A simplified verification model of combustion is also given. Chapter 8 compares the propagation phase of gas and liquid fuels during the side direct fuel injection (on the cylinder wall) and direct fuel injection from the cylinder head and the thermodynamic parameters of the charge in the compression process. The formation of the components during the combustion process in the direct fuel injection two-stroke engine was determined by numerical calculations and the results are given in Chapter 9. Chapter 10 describes the work parameters of the two-stroke engine with direct fuel injection carried out at CUT on the laboratory stands. This chapter also presents CFD simulations of the fuel propagation and combustion process, taking into account the formation of toxic components and exhaust gas emissions. The processes of two direct rich mixture injection systems: fully atomized stratified turbulence (FAST) developed by Piaggio and rich mixture injection system (RMIS) developed at CUT are presented in Chapter 11. Miscellaneous problems of direct fuel injection, such as characteristics of fuel injectors, problems of direct gaseous fuel injection, and application of fuelling systems in outboard engines and snowmobile vehicles, are presented in Chapter 12, which also contains a comparison of the working parameters in two- and four stroke engines. The last chapters contain the final conclusions and remarks concerning fuel injection and emission of exhaust gases in low-power two-stroke engines. This book is intended for students of internal combustion engines at technical colleges, engineers, and researchers and also partly for research institutes associated with the automotive industry.