Direct numerical simulation of interacting inertial particles in homogeneous isotropic turbulence

This study has developed an efficient parallel simulation code for interacting inertial particles in homogeneous isotropic turbulence. Flow is computed with a fourth-order finite-difference method and particles are tracked with the Lagrangian method. The code adopts an MPI library for a distributed-memory parallelization and is designed to minimize the MPI communication, which leads to a high parallel performance. The code has been run to obtain collision statistics of a monodisperse system with St = 0.4 particles, where St is the Stokes number representing the particle relaxation time relative to the Kolmogorov time. The attained Taylor-microscale based Reynolds number R-lambda ranges from 50 to over 500. This wide range of R-lambda has potential to reveal a Reynolds dependency of collision statistics.