Droplet processes

Droplet properties have an important impact on the transport phenomena in associated droplet processes. A thorough understanding of fundamental phenomena, principles and mechanisms in droplet processes is therefore needed in order to enhance efficiency of droplet generation, and to control droplet properties. In this chapter, the mechanisms governing droplet generation and deformation in various droplet processes are reviewed in detail. 

Atomization, or generally speaking droplet generation, is an extremely complex process that cannot yet be precisely predicted theoretically. The lack of general theoretical treatment of droplet processes has led to the development of numerous empirical correlations for droplet properties as a function of process parameters and material properties. In this chapter, empirical and analytical correlations for the prediction of droplet properties, such as droplet size distribution and droplet deformation characteristics will be summarized from experimental observations and theoretical analyses in available literature. 

Theoretical Calculations and Numerical Modeling of Droplet Processes... 

As for normal liquids, modeling of droplet processes of melts provides tremendous opportunities to improve the understanding of the fundamental phenomena and underlying physics in the processes. It also provides basic guidelines for optimization and on-line control of the processes. This section is devoted to a comprehensive review of process models, computational methods, and numerical modeling results of the droplet processes of melts. The emphasis of this section will be placed on the droplet processes in spray atomization for metal powder production, and spray forming for near-net shape materials synthesis and manufacturing. Details of these processes have been described in Ref. 3. 

In this chapter, the primary measurement techniques for droplet properties are outlined, and their capabilities and limitations are discussed. The approaches to intelligent process control as related to droplet processes are presented along with descriptions of recent developments. 

There have been books on droplet-related processes. However, the present book is probably the first one that encompasses the fundamental phenomena, principles and processes of discrete droplets of both normal liquids and melts. The author has attempted to correlate many diverse mechanisms and effects in a single and common framework in an effort to provide the reader with a new perspective of the identical basic physics and the inherent relationship between normal liquid and melt droplet processes. Another distinct and unique feature of this book is the comprehensive review of the empirical correlations, analytical and numerical models and computer simulations of droplet processes. These not only provide practical and handy approaches for engineering calculations, analyses and designs, but also form a useful basis for future in-depth research. Therefore, the present book covers the fundamental aspects of engineering applications and scientific research in the area. 

An imderstanding and analysis of single-droplet processes is necessary to understand oil combustion better. 

The population balance approach is employed for the description of droplet dynamics in various flow fields. A significant advantage of the method is that a vehicle is provided to include the details of the breakage and coalescence processes in terms of the physical parameters and conditions of operation. A predictive multidimensional particle distribution theory is at hand which, in the case of well-defined droplet processes, can be employed for a priori prediction of the form and the magnitude of the particle size distribution. The physical parameters which affect the form... 

---