Resolution Dependence of Cloud-Wind Simulations

TL;DR

This study examines how numerical resolution and wind speed influence cloud evolution in wind-tunnel simulations, revealing complex resolution effects and the importance of resolution choice in modeling cloud dynamics.

Contribution

It provides new insights into the resolution dependence of cloud-wind interactions across subsonic and supersonic regimes, highlighting non-monotonic trends.

Findings

Resolution significantly affects cloud evolution.

16 cells per cloud radius is a key resolution in subsonic cases.

Supersonic cases show more monotonic resolution trends.

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.