@article{ISI:000388530700012,
 abstract = {We obtain the probability distribution functions (PDFs) of the time that
a Lagrangian tracer or a heavy inertial particle spends in vortical or
strain-dominated regions of a turbulent flow, by carrying out direct
numerical simulations of such particles advected by statistically
steady, homogeneous, and isotropic turbulence in the forced,
three-dimensional, incompressible Navier-Stokes equation. We use the two
invariants, Q and R, of the velocity-gradient tensor to distinguish
between vortical and strain-dominated regions of the flow and partition
the Q-R plane into four different regions depending on the topology of
the flow; out of these four regions two correspond to
vorticity-dominated regions of the flow and two correspond to
strain-dominated ones. We obtain Q and R along the trajectories of
tracers and heavy inertial particles and find out the time t(pers) for
which they remain in one of the four regions of the Q-R plane. We find
that the PDFs of tpers display exponentially decaying tails for all four
regions for tracers and heavy inertial particles. From these PDFs we
extract characteristic time scales, which help us to quantify the time
that such particles spend in vortical or strain-dominated regions of the
flow.},
 article-number = {053119},
 author = {Bhatnagar, Akshay and Gupta, Anupam and Mitra, Dhrubaditya and Pandit,
Rahul and Perlekar, Prasad},
 doi = {10.1103/PhysRevE.94.053119},
 eissn = {2470-0053},
 issn = {2470-0045},
 journal = {PHYSICAL REVIEW E},
 month = {NOV 23},
 number = {5},
 orcid-numbers = {Gupta, Anupam/0000-0002-7335-0584},
 researcherid-numbers = {Gupta, Anupam/N-4777-2018},
 times-cited = {5},
 title = {How long do particles spend in vortical regions in turbulent flows?},
 unique-id = {ISI:000388530700012},
 volume = {94},
 year = {2016}
}