We present results from recent direct numerical simulations of heavy particle transport in homogeneous, isotropic, fully developed turbulence, with grid resolution up to 5123 and R¿ ˜ 185. By following the trajectories of millions of particles with different Stokes numbers, St ¿ [0.16 : 3.5], we are able to characterize in full detail the statistics of particle acceleration. We focus on the probability density function of the normalised acceleration a/arms and on the behaviour of their rootmean-squared acceleration arms as a function of both St and R¿. We explain our findings in terms of two concurrent mechanisms: particle clustering, very effective for small St, and filtering induced by finite particle response time, taking over at larger St.
|Title of host publication||Proceedings of the IUTAM Symposium on Computational Physics and New Perspectives in Turbulence (Nagoya, Japan, September, 11-14, 2006)|
|Publication status||Published - 2008|