Development of a GPU based Smoothed Particle Hydrodynamics Method for Modeling Active Nematics

This paper proposes a novel active nematic flow solver based on the particle based Langrangian smoothed particle hydrodynamics (SPH) method accelerated on the CUDA platform. Nematohydrodynamics equations are discretized using the SPH algorithm, and the periodic domain is enforced using the periodic ghost boundary condition. Flow behavior, nematic ordering, topological defects, velocity and vorticity correlations are calculated and discussed in detail. Due to the high particle resolution, the spectrum of the kinetic energy with respect to the wavenumber is calculated, and universal relation is observed for the nematic flow. To exploit the SPH capabilities, pathlines of nematic particles are evaluated during the simulation. Finally, the mixing behavior of the active nematics is calculated as well and described qualitatively. The effects of two important parameters, namely, activity and elastic constant are investigated. It is shown that the activity intensifies the chaotic nature of the active nematic by increasing the pathline and mixing efficiency, while the elastic constant behaves oppositely.