ABSTRACT
Dimensional theory can be very helpful for the mathematical solution of some physical problems. This chapter provides several examples of such applications of dimensional theory. It then considers the flow of an incompressible viscous fluid past a plane infinitely thin plate. Many fluid motions that can be observed in nature and the majority of motions in technical engineering are characterized by the presence of random unsteady motion superimposed on the main motion of fluid, which can be represented as a certain statistically average motion. This kind of fluid motion is called turbulent motion. Experiment shows that at high Reynolds numbers, (i.e., at high velocities and large scales) laminar steady fluid motions become unstable and become unsteady turbulence motions, which, on the average, in a number of cases can be steady state. The laws of development of turbulence are obtained by means of a supplementary assumption of Karman and Howarth.
