Abstract:
In this paper the "Bernoulli's Equilibrium Vorticity" and the "Deviation of the BEV" are defined and a random dynamic model, which can give both Lagrangian and Eulerian autocorrelation functions, are set up for wind velocity fluctuations in the stationary, homogeneous turbulence. Under Taylors hypothesis of "frizened eddies", the ratio of Lagrangian time scale to Eulerian is given as a function of the deviation of wind diraction, that has asymptotic form 0.71/i where i is the intensity of the turbulence, if the turbulence is isotropic.