Resolution Dependence of Cloud-Wind Simulations

Abstract

Using a set of wind-tunnel simulations, we investigate the effect that numerical resolution has on cloud evolution and acceleration. We also consider the role of wind speed in both the subsonic and supersonic regimes, using adiabatic simulations with wind speeds of 100 km/s and 1000 km/s, respectively. For each setup, we explore five numerical resolutions. We find that the fate of the cloud is significantly affected by the resolution, but the trend is surprisingly non-monotonic. In the subsonic case, we find that a resolution of 16 cells per cloud radius is a turning point in the cloud evolution. In the supersonic case the trend is more monotonic, consistent with the difference in timescales for which ram pressure acceleration dominates over mixing in the early acceleration.