1 Fluid Mechanics

Fluid mechanics deals with the flow of fluids. Its study is important to physicists, whose main interest is in understanding phenomena. They may, for example, be interested in learning what causes the various types of wave phenomena in the atmosphere and in the ocean, why a layer of fluid heated from below breaks up into cellular patterns, why a tennis ball hit with "top spin" dips rather sharply, how fish swim, and how birds fly. The study of fluid mechanics is just as important to engineers, whose main interest is in the applications of fluid mechanics to solve industrial problems. Aerospace engineers may be interested in designing airplanes that have low resistance and, at the same time, high "lift" force to support the weight of the plane. Civil engineers may be interested in designing irrigation canals, dams, and water supply systems. Pollution control engineers may be interested in saving our planet from the constant dumping of industrial sewage into the atmosphere and the ocean. Mechan-ical engineers may be interested in designing turbines, heat exchangers, and fluid couplings. Chemical engineers may be interested in designing efficient devices to mix industrial chemicals. The objectives of physicists and engineers, however, are not quite separable because the engineers need to understand and the physicists need to be motivated through applications.

Fluid mechanics, like the study of any other branch of science, needs mathemat-ical analyses as well as experimentation. The analytical approaches help in finding the solutions to certain idealized and simplified...