Published online by Cambridge University Press: 12 February 2014
In this work, the scaling statistics of the dissipation along Lagrangian trajectories are investigated by using fluid tracer particles obtained from a high-resolution direct numerical simulation with $\mathit{Re}_{\lambda }=400$. Both the energy dissipation rate
$\epsilon $ and the local time-averaged
$\epsilon _{\tau }$ agree rather well with the lognormal distribution hypothesis. Several statistics are then examined. It is found that the autocorrelation function
$\rho (\tau )$ of
$\ln (\epsilon (t))$ and variance
$\sigma ^2(\tau )$ of
$\ln (\epsilon _{\tau }(t))$ obey a log-law with scaling exponent
$\beta '=\beta =0.30$ compatible with the intermittency parameter
$\mu =0.30$. The
$q{\rm th}$-order moment of
$\epsilon _{\tau }$ has a clear power law on the inertial range
$10<\tau /\tau _{\eta }<100$. The measured scaling exponent
$K_L(q)$ agrees remarkably with
$q-\zeta _L(2q)$ where
$\zeta _L(2q)$ is the scaling exponent estimated using the Hilbert methodology. All of these results suggest that the dissipation along Lagrangian trajectories could be modelled by a multiplicative cascade.