Transition to Turbulence

Abstract

We have spent several chapters discussing various type of instabilities in a number of flow situations. In this final chapter we will consider how these instabilities may trigger laminar-turbulent transition. The transition process is often complicated and can follow many possible routes. We shall try to classify these routes based on the mechanisms responsible for the disturbance growth. In this introductory section we will discuss three typical scenarios for the simplified flow situation of a parallel boundary layer growing in time; in the subsequent sections examples of more complicated flow situations will be given. First, however, we will briefly summarize some earlier attempts to classify transition.