GPU accelerated lattice Boltzmann simulation for rotational turbulence

In this work, we numerically study decaying isotropic turbulence in periodic cubes with frame rotation using the lattice Boltzmann method (LBM) and present the results of rotation effects on turbulence. The implementation of LBM is on a GPU (Graphic Processing Unit) platform using CUDA (Compute Unified Device Architecture). Through the accelerated GPU-LBM simulation, we look into various effects of frame rotation on turbulence. It has been observed that rotation slows down the decay of kinetic energy and enstrophy. Rotation also breaks isotropy and induces vortex tubes in the direction of frame rotation. Characteristics related to velocity and its derivatives have been studied with and without rotation. Without rotation, the kinetic energy and enstrophy decay follow −10/7 and −17/7 scaling respectively whereas in the presence of rotation with the relatively small Rossby number (large rotation intensity), the energy decay slows down to −5/21 scaling when the initial isotropic turbulence energy spectrum is scaled to k4. These scalings with and without rotation are in quantitative agreements with the predictions fromKolmogorov hypotheses respectively. The skewness and kurtosis are seen more fluctuating in rotational turbulence, which agrees with the results from NS-based computation. Using this accelerated and validated GPU-LBM computation tool, we are further studying the inverse energy transfer behavior with and without rotation aiming to quantify the effects of rotation on the inverse energy transfer to reveal underlying physics of a particular stage of the turbulence development. The results will be presented in near future. Published by Elsevier Ltd