Heavy inertial particles in rotating turbulence : distribution of particles in flow and evolution of Lagrangian trajectories

Abstract: We revisited the problem of heavy particles suspended in homogeneous box turbulence flow subjected to rotation along the vertical axis, which introduces anisotropy along the vertical and horizontal planes. We investigate the effect of the emergent structures due to rotation, on the spatial distribution and temporal statistics of the particles. The spatial distributions were studied using the joint probability distribution function (JPDFs) of the two invariants, $Q$ and $R$, of the velocity gradient tensor. At high rotation rates, the JPDFs of Lagrangian $Q-R$ plots show remarkable deviations from the well known \textit{teardrop} shape. The cumulative probability distribution functions (CDFs) for times during which a particle remains in vortical or straining regions, show exponentially decaying tails except for the deviations at the highest rotation rate. The average residence times of the particles in vortical and straining regions are also affected considerably due to the addition of rotation. In addition, we compute the temporal velocity autocorrelation and connect it to the Lagrangian anisotropy in presence of rotation. The spatial and temporal statistics of the particles are determined by a complex competition between the rotation rate and the heaviness of the particles.