Conventional and Innovative Spray Generation for Combustion Applications

The atomization and dispersion of fuel is a fundamental stage in any combustion process involving liquid fuels. Atomization quality and efficient coupling with the airflows plays a key role in determining the performance and pollutant emissions from such systems. This chapter introduces the basic concepts of liquid atomization, and provides an overview of the dependence of the relevant processes on the combustion system parameters and the liquid properties. The main implications of theory on the practical aspects of atomization are reviewed and discussed. A conceptual classification of atomizers used in combustion systems is also presented. Practical atomization techniques and devices are presented in relation to the most important applications for energy production and propulsion. Brief details are also provided of selected innovative atomization techniques, with particular emphasis on high-pressure combustion systems used in propulsion applications. Among the cited literature, books and reviews have been generally preferred as these already include selected bibliographies on specific topics, and represent a good starting point for more detailed studies. Keywords: Atomization; liquid fuels; sprays; atomizers; nozzles; jets in crossflow; high-energy ultrasonic injection; diesel sprays; spray technology