Turbulence

Abstract

Turbulence is generally considered to be some kind of a disordered flow. In the first section we will try to clarify as much as possible what sort of an irregular flow is going to be termed turbulent. It will be taken for granted that turbulence will be described by the Navier-Stokes equation. This equation is Newton’s law for fluid motion and is written as

$$ \frac{{\partial \vec v}} {{\partial t}} + (\vec v.\vec \nabla )\vec v = - \frac{1} {\rho }\vec \nabla P + v\nabla ^2 \vec v + \vec f $$

(8.1.1)