Conditional and unconditional acceleration statistics in turbulence

摘要: In this paper we study acceleration statistics from laboratory measurements and direct numerical simulations in three-dimensional turbulence at Taylor-scale Reynolds numbers ranging 38 to 1000. Using existing data, show that present it is not possible infer the precise behavior of unconditional variance large number limit, since empirical functions satisfying both Kolmogorov refined theories appear fit data equally well. We also entirely new for covariance conditioned on velocity, showing these conditional are strong but when scaled by they only weakly dependent number. For values magnitude u conditioning velocity speculate behaves like u6 qualitatively consistent with stretched exponential tails proba...