Abstract
A new approach of turbulence is developed, based on the simultaneous analysis of the dynamical mechanisms governing the Lagrangian evolution of velocity increments and of their statistical effects. The corresponding Fokker-Planck equation is derived, including the three inertial effects (amplification of rotation by stretching, negative feedback of rotation on stretching and scale stretching), pressure, viscous diffusion and forcing. Their influence on the cascade is then investigated and discussed.