A PARADOX OF THE 1D SURROGATE OF DISSIPATION RATE IN ISOTROPIC TURBULENCE

It is pointed out within the framework of Kolmogorov and Obukhov's ref ined similarity hypothesis that the 1D surrogate of energy dissipation rate in isotropic turbulence, which has been conventionally used by m any experimentalists to investigate intermittency in isotropic turbule nce, leads to an unrealistic prediction of the probability density fun ction of velocity gradient. This suggests that any discussion of inter mittency of turbulence based on the 1D surrogate may be of a more or l ess qualitative nature.