The Origin of Species Charles Darwin The origin of turbulence in fluids
is a long-standing problem and has been the focus of research for
decades due to its great importance in a variety of engineering
applications. Furthermore, the study of the origin of turbulence is part
of the fundamental physical problem of turbulence description and the
philosophical problem of determinism and chaos. At the end of the
nineteenth century, Reynolds and Rayleigh conjectured that the reason of
the transition of laminar flow to the 'sinuous' state is in- stability
which results in amplification of wavy disturbances and breakdown of the
laminar regime. Heisenberg (1924) was the founder of linear hydrody-
namic stability theory. The first calculations of boundary layer
stability were fulfilled in pioneer works of Tollmien (1929) and
Schlichting (1932, 1933). Later Taylor (1936) hypothesized that the
transition to turbulence is initi- ated by free-stream oscillations
inducing local separations near wall. Up to the 1940s, skepticism of the
stability theory predominated, in particular due to the experimental
results of Dryden (1934, 1936). Only the experiments of Schubauer and
Skramstad (1948) revealed the determining role of insta- bility waves in
the transition. Now it is well established that the transition to
turbulence in shear flows at small and moderate levels of environmental
disturbances occurs through development of instability waves in the
initial laminar flow. In Chapter 1 we start with the fundamentals of
stability theory, employing results of the early studies and recent
advances.
