An Introduction to Fluid Mechanics

Our task is to learn to model flows. To set up the models, we draw on our intuition of how fluids behave; for example, we often can guess the direction that a flow takes under the influence of particular forces. Intuition also may enable us to identify symmetries in a flow field. Intuition comes from experience, however, and for introductory students, experience may be in short supply.

One solution to a lack of experience is to experiment with fluids. Unfortunately, not all of us have access to pumps, flow meters, and piping systems; therefore, it is worthwhile to take a laboratory course in fluid mechanics, if possible. Another way to build experience with fluid behavior is to view flow-visualization videos. Between 1961 and 1969, a group of experts in fluid mechanics (the National Committee for Fluid Mechanics Films [NCFMF]) produced a series of flow- demonstration films [112] that introduce fluid behavior; the films and film notes are now available on the Internet. There also are books [170] and other media [65] that catalog fluid behavior, as well as Web sites on which researchers have posted flow-visualization videos, including the Gallery of Fluid Motion [133], and elsewhere [182]. These sites bring to life all types of fluid behavior, from the mundane to the esoteric.