Turbulent particle pair diffusion: Numerical simulations

dc.creatorMalik, Nadeem A. (TTU)
dc.description© 2019 Nadeem A. Malik. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. cc-by
dc.description.abstractA theory for turbulent particle pair diffusion in the inertial subrange [Malik NA, PLoS ONE 13 (10):e0202940 (2018)] is investigated numerically using a Lagrangian diffusion model, Kinematic Simulations [Kraichnan RH, Phys. Fluids 13:22 (1970); Malik NA, PLoS ONE 12(12): E0189917 (2017)]. All predictions of the theory are observed in flow fields with generalised energy spectra of the type, E(k) ∼ k-p. Most importantly, two non-Richardson regimes are observed: For short inertial subrange of size 102 the simulations yield quasi-local regimes for the pair diffusion coefficient, K(l) ∼ s(1+p)=2 l ; and for asymptotically infinite inertial subrange the simulations yield non-local regimes K(l) ∼ sg l , with γ intermediate between the purely local scaling γl = (1 + p)/2 and the purely non-local scaling γnl = 2. For intermittent turbulence spectra, E(k) ∼ k-1.72, the simulations yield K ∼ σ1:556 l , in agreement with the revised 1926 dataset K ∼ σ1:564 l [Richardson LF, Proc. Roy. Soc. Lond. A 100:709 (1926); Malik NA, PLoS ONE 13(10):e0202940 (2018)]. These results lend support to the physical picture proposed in the new theory that turbulent diffusion in the inertial subrange is governed by both local and non-local diffusion transport processes.
dc.identifier.citationMalik, N.A.. 2019. Turbulent particle pair diffusion: Numerical simulations. PLoS ONE, 14(5). https://doi.org/10.1371/journal.pone.0216207
dc.titleTurbulent particle pair diffusion: Numerical simulations


Original bundle

Now showing 1 - 1 of 1
Thumbnail Image
Main article with TTU Libraries cover page.pdf
3.28 MB
Adobe Portable Document Format