Probability density function of longitudinal velocity increment

摘要

In this paper we present an analysis of the PDF for the longitudinal velocity increment with the aid of the conditional average method (CAM). The functional forms of the necessary averages are derived and compared with the results of simulation. The derived PDF is categorically shown; the Gaussian for small amplitudes, the stretched exponential for intermediate ones and the exponential for large ones. The comparison with the PDF obtained in high Reynolds number flows is given.