Introduction

Abstract

The structure of thermo-fluid sciences rests on three pillars, namely fluid mechanics, thermodynamics, and heat transfer. While fluid mechanics principles are involved in open system thermodynamics processes, they play a primary role in every convective heat transfer problem. Fluid mechanics deals with the motion of fluid particles and describe their behavior under any dynamic condition where the particle velocity may range from low subsonic to hypersonic. It also includes the special case termed fluid statics, where the fluid velocity approaches zero. Fluids are encountered in various forms including homogeneous liquids, unsaturated, saturated, and superheated vapors, polymers and inhomogeneous liquids and gases. As we will see in the following chapters, only a few equations govern the motion of a fluid that consists of molecules. At microscopic level, the molecules continuously interact with each other moving with random velocities. The degree of interaction and the mutual exchange of momentum between the molecules increases with increasing temperature, thus, contributing to an intensive and random molecular motion.