Transport Phenomena Fundamentals, 4th Edition

11

Macroscopic or Engineering Balances

11.1 Introduction

In the previous chapter, we derived the microscopic balance equations governing the conservation of mass, energy, momentum, and charge. These balances were very complicated and actual engineering situations rarely lend themselves to analyses using the full set of balance equations. Flows are most likely turbulent and require a full three-dimensional momentum treatment. The physical systems are often highly irregular in shape so mass or heat balances cannot be simplified. Finally, the media through which transport takes place are often multi-component systems with properties varying ...