Multiscale analysis of inertial particle dynamics in turbulent flows using a tessellation-based method

Inertial particle-laden turbulent flows, characterized by multiscale clusters and voids, play a crucial role in numerous natural and engineering systems. The formation and destruction of clusters is critical and the particle velocity divergence plays a key role for the dynamics.

We study three-dimensional direct numerical simulation data of isotropic turbulence with inertial particles considering seven different Stokes numbers and the influence of gravity. We apply a tessellation-based technique and thus assign a volume to each particle. The temporal rate of change of the volumes yields the divergence of the particle velocity (Maurel-Oujia et al., arXiv:2212.03580, 2023).

In addition, we perform a multiresolution analysis of the divergence on unstructured discrete particle positions (Matsuda et al., CTR Proc., 2022). The multiscale clustering dynamics can be assessed and the scales where the clustering formation and destruction are most active, can be determined depending on the Stokes number and the gravity.