From particles to precision. Simulating subsonic turbulence with Smoothed Particle Hydrodynamics

Direct numerical simulation of subsonic turbulence with smoothed particle hydrodynamics (SPH) has traditionally been hampered by zeroth-order (E0) errors, inaccurate gradient evaluations, and excessive numerical dissipation. We demonstrate that the recently developed SPH-EXA code can overcome these challenges, producing results similar to those of other state-of-the-art non-SPH codes, such as AREPO and GIZMO. We show that SPH-EXA accurately reproduces the Kolmogorov inertial range scaling in the subsonic regime with increasing resolution, closely matching state-of-the-art non-SPH methods. This is an outstanding result given the important role of SPH codes in astrophysics and cosmology, and the ubiquity of turbulent phenomena.