Measurement Techniques in Laboratory Rotating Flows

Abstract

The purpose of this chapter is to survey classical and modern measurement techniques used in rotating flow experiments. Since the measurement of rotating flows is now a broad and rapidly developing art, it is clear that only a summary of the essential features of each measurement system can be given. Here we will be primarily concerned with flows driven by rotating boundaries, rotational flows produced inside stationary boundaries, motion driven by thermal heating of a fluid in a basic state of rotation and other flows for which rotational forces are of primary importance. Free vortex flows in the absence of rotation, wind tunnel flow over rotating bodies, and rotating liquid helium flows which necessitate specialized measurement techniques are excluded. Equations and diagrams are incorporated only when they add substantially to the understanding of the operation of a particular measurement system. An attempt is made to include historical perspective and development. Also, I felt it was important to provide an extensive bibliography to exhibit the range of applications of each measurement technique and thereby provide guidance for the experimentalist interested in rotating flows.