Pair statistics of oblate spheroids settling in a turbulent flow

Abstract

We perform direct numerical simulations of sub-Kolmogorov, inertial spheroids settling under gravity in homogeneous, isotropic turbulence and find that small-scale clustering, measured via the correlation dimension, depends sensitively on their aspect ratios. In particular, such particles are shown to cluster more as their anisotropy increases. Further, the approach rate for pairs of spheroids are calculated and found to deviate significantly from the spherical-particle limit. Our study, spanning a range of Stokes numbers and aspect ratios, provides critical inputs for developing collision models to understand the dynamics of sedimenting, anisotropic particles in general and ice crystals in clouds in particular.

References in corpus (22)

• Heavy particle concentration in turbulence at dissipative and inertial scales
• Fractal clustering of inertial particles in random flows
• Lagrangian dynamics and statistical geometric structure of turbulence
• The effect of Reynolds number on inertial particle dynamics in isotropic turbulence. Part I: Simulations without gravitational effects
• Gravity-driven enhancement of heavy particle clustering in turbulent flow
• Clustering and collisions of heavy particles in random smooth flows
• Orientation dynamics of small, triaxial-ellipsoidal particles in isotropic turbulence
• Statistical models for the dynamics of heavy particles in turbulence
• Extreme fluctuations of the relative velocities between droplets in turbulent airflow
• Statistical model for the orientation of non-spherical particles settling in turbulence
• Theory for the effect of fluid inertia on the orientation of a small particle settling in turbulence
• Importance of fluid inertia for the orientation of spheroids settling in turbulent flow
• Abrupt growth of large aggregates by correlated coalescences in turbulent flow
• Orientation Dynamics of Sedimenting Anisotropic Particles in Turbulence
• Effect of particle inertia on the alignment of small ice crystals in turbulent clouds
• Hydrodynamic interactions and extreme particle clustering in turbulence
• Flow structures govern particle collisions in turbulence
• Sticky elastic collisions
• Flocking of Active Particles in a Turbulent Flow
• Elliptical Tracers in Two-dimensional, Homogeneous, Isotropic Fluid Turbulence: the Statistics of Alignment, Rotation, and Nematic Order
• Inertial spheroids in homogeneous, isotropic turbulence
• Velocity and acceleration statistics of heavy spheroidal particles in turbulence