Fundamental Fluid Mechanics

Abstract

In this chapter we investigate some typical fluid motions (fluid dynamics) in an elementary way. We will discuss in some detail the use of Newton’s second law (F ? ma) as it is applied to fluid particle motion that is “ideal” in some sense. We will obtain the celebrated Bernoulli equation and apply it to various flows. Although this equation is one of the oldest in fluid mechanics and the assumptions involved in its derivation are numerous, it can be used effectively to predict and analyze a variety of flow situations. However, if the equation is applied without proper respect for its restrictions, serious errors can arise. Indeed, the Bernoulli equation is appropriately called “the most used and the most abused equation in fluid mechanics.” A thorough understanding of the elementary approach to fluid dynamics involved in this chap- ter will be useful on its own. It also provides a good foundation for the material in the following chapters where some of the present restrictions are removed and “more nearly exact” results are presented. 93