Inter-particle collision in particle-laden isotropic turbulence

Direct numerical simulations of heavy particles in isotropic homogeneous turbulence are performed to study inter-particle collisions in a wide range of Stokes numbers. Dynamics of the particles are described by Stokes drag including particle-particle interactions via hard-sphere collisions while fluid turbulence is solved using a pseudo-spectral method. The statistics related to rotation and dissipation rates as well as collision frequency are investigated. A particular emphasis is placed on the statistics of the fluid experienced by heavy particles, which provide essential information on the collision process. A plausible explanation of the collision mechanism for various Stokes numbers is provided.