GPU acceleration of Eulerian-Lagrangian particle-laden turbulent flow simulations

Acceleration of an existing MPI-based, particle-laden turbulent flow simulation code is achieved using up to four NVIDIA GPU devices. The overall design is to transfer the entire flow velocity, temperature, and humidity fields to each device, and compute particle trajectories entirely on the GPU hardware. For one-way coupled turbulent flow simulations, accurate simulations can be achieved for less computational cost than the original CPU implementation for particle numbers above 106. Above 107 particles, the GPU version is roughly 14 times faster than the original CPU implementation. The effects of interpolation order, precision of the transferred Eulerian fields, and sub-time-stepping for fast particle dynamics are discussed.