ABSTRACT
This chapter reviews the basic fluid dynamics concepts needed in two-phase flow modeling. A sound understanding of the physics of single-phase flow and a mastery of solution techniques for single-phase flow problems are important prerequisites for studying two-phase or multiphase flow systems. Two-phase flow is best described as the flow of two different kinds of matter, e.g., solid particles in a gas or liquid, gas bubbles in a liquid, or droplets in a gas stream. Within the continuum mechanics framework, two basic flow field descriptions are of interest, i.e., the Lagrangian viewpoint and the Eulerian approach. In the Eulerian framework an "open system" is considered where mass, momentum, and energy may readily cross, i.e., being convected across the control volume surface and local fluid flow changes may occur within the control volume over time. The chapter also presents an overview of the key concepts discussed in this book.
