Extreme divergence and rotation values of the inertial particle velocity in high Reynolds number turbulence using Delaunay tesselation

Thibault Oujia (1) , Keigo Matsuda (2) , Kai Schneider (1)

1 I2M - Institut de Mathématiques de Marseille
2 JAMSTEC - Japan Agency for Marine-Earth Science and Technology

The dynamics of inertial particles in homogeneous isotropic turbulence at high Reynolds number, obtained by three-dimensional direct numerical simulation (DNS), is analyzed considering different Stokes numbers. Divergence and rotation of the particle velocity are determined using Delaunay tessellation of the particle positions at subsequent time instants. For large Stokes numbers heavy tails in the probability density functions (PDFs) are found. Large divergence and rotation values, as large as 50 and 40 times of the corresponding standard deviation, respectively, can be observed. The helicity of the particle velocity, which quantifies the swirling motion of the particle flow, is likewise computed. The PDFs change their shape with the Stokes number and show that for large numbers higher probability for vanishing helicity is found. This confirms that for heavy particles helical motion is apparently suppressed.

Domaines: Mécanique des fluides [physics.class-ph]

Thibault Oujia, Keigo Matsuda, Kai Schneider. Extreme divergence and rotation values of the inertial particle velocity in high Reynolds number turbulence using Delaunay tesselation. 12th International Symposium on Turbulence and Shear Flow Phenomena (TSFP12), Jul 2022, Osaka, Japan. ⟨hal-03751172⟩