Continuous time random walks for the evolution of Lagrangian velocities

M Dentz, PK Kang, A Comolli, T Le Borgne… - Physical Review Fluids, 2016 - APS
We develop a continuous time random walk (CTRW) approach for the evolution of
Lagrangian velocities in steady heterogeneous flows based on a stochastic relaxation …

A Lagrangian fluctuation–dissipation relation for scalar turbulence. Part I. Flows with no bounding walls

TD Drivas, GL Eyink - Journal of Fluid Mechanics, 2017 - cambridge.org
An exact relation is derived between scalar dissipation due to molecular diffusivity and the
randomness of stochastic Lagrangian trajectories for flows without bounding walls. This …

Turbulent pair dispersion as a ballistic cascade phenomenology

M Bourgoin - Journal of Fluid Mechanics, 2015 - cambridge.org
Since the pioneering work of Richardson in 1926, later refined by Batchelor and Obukhov in
1950, it is predicted that the rate of separation of pairs of fluid elements in turbulent flows …

Exact Results for the Nonergodicity of -Dimensional Generalized Lévy Walks

T Albers, G Radons - Physical review letters, 2018 - APS
We provide analytical results for the ensemble-averaged and time-averaged squared
displacement, and the randomness of the latter, in the full two-dimensional parameter space …

Non-local dispersion and the reassessment of Richardson's t3-scaling law

GE Elsinga, T Ishihara, JCR Hunt - Journal of Fluid Mechanics, 2022 - cambridge.org
The Richardson-scaling law states that the mean square separation of a fluid particle pair
grows according to t3 within the inertial range and at intermediate times. The theories …

Universal alignment in turbulent pair dispersion

R Shnapp, S Brizzolara, MM Neamtu-Halic… - Nature …, 2023 - nature.com
Countless processes in nature and industry, from rain droplet nucleation to plankton
interaction in the ocean, are intimately related to turbulent fluctuations of local …

Mechanisms of anomalous dispersion in flow through heterogeneous porous media

A Tyukhova, M Dentz, W Kinzelbach, M Willmann - Physical Review Fluids, 2016 - APS
We study the origins of anomalous dispersion in heterogeneous porous media in terms of
the medium and flow properties. To identify and quantify the heterogeneity controls, we …

On local isotropy and scale dependence of pair dispersion in turbulent canopy flows

R Shnapp, A Liberzon, Y Bohbot-Raviv… - Journal of Fluid …, 2024 - cambridge.org
Canopy flows in the atmospheric surface layer play important economic and ecological
roles, governing the dispersion of passive scalars in the environment. The interaction of high …

Coupled continuous-time random walks for fluid stretching in two-dimensional heterogeneous media

M Dentz, DR Lester, T Le Borgne, FPJ De Barros - Physical Review E, 2016 - APS
We study the relation between flow structure and fluid deformation in steady flows through
two-dimensional heterogeneous media, which are characterized by a broad spectrum of …

Nonergodicity of -dimensional generalized Lévy walks and their relation to other space-time coupled models

T Albers, G Radons - Physical Review E, 2022 - APS
We investigate the nonergodicity of the generalized Lévy walk introduced by Shlesinger et
al.[Phys. Rev. Lett. 58, 1100 (1987) PRLTAO 0031-9007 10.1103/PhysRevLett. 58.1100] …