Preface

Droplet dynamics can be used in many industrial and technical applications, such as coating machines, cooling systems, gas turbines, spray painting, nozzle baffle valves in hydraulic systems, and combustion engines in marine and aircraft vehicles. Different applications require different solutions and effects. In small combustion engines, such as direct injection spark-ignition (DISI) gasoline commercial vehicles, impingement of atomized droplets on the piston head and cylinder wall affects the mixture formation prior to combustion and thus influences engine performance and pollutant emissions. Especially during the warmup or cold start condition, the droplets impact the wall to form liquid adhesion before evaporation, resulting in unburned hydrocarbons. Even in marine and aircraft engines with less consideration of emissions, droplets impacting and adhering to the wall may decrease the efficiency and performance of the engine, leading to more fuel storage. As such, droplet behavior is a basic scientific and critical issue for investigation. Furthermore, mastering the principles of droplet dynamics helps to optimize simulation models and improve computational efficiency and accuracy.

This book on fundamental research and application of droplet dynamics includes six chapters that address such topics as droplet behaviors, experimental methods for investigations, multiple droplet characteristics, liquid transportation in atmospheric pressure plasmas, liquid spray and atomization in a nozzle, and droplets in bioinspired smart surfaces. In practice, these aspects must be considered together to maximize the understanding and application of droplet dynamics. The chapters are organized into four sections on concepts, investigation methods, fundamental research, and applications.

A comprehensive analysis of the technology and application of droplet dynamics is beyond the scope of this book. However, the content of this volume is useful for audiences to broaden their knowledge of liquid droplet behaviors. This book may serve both as a graduate-level textbook for mechanical engineering students and as a reference for professional engineers in the industry.

The research necessary to write and edit this book was carried out during my employment as an assistant professor at Hiroshima University, Japan. I am grateful for my experiences there as well as the support of my colleagues. I would also like to thank IntechOpen for inviting me to be the editor of this volume, especially Ms. Ana Javor and the publishing process staff for their help in coordinating the reviews, editing, and printing of this book.

> **Dr. Hongliang Luo** College of Power and Energy Engineering, Harbin Engineering University, Harbin, China

**1**

Section 1

Introduction
