Why FARGO3D reaches the high-resolution velocity distribution faster

Determine why the FARGO3D simulations produce meridional dust-velocity distributions at low resolution that are already close to the distributions obtained at the highest resolution, unlike the corresponding PLUTO fluid and particle simulations.

Background

At low resolution, FARGO3D produces substantially broader meridional dust-velocity distributions than PLUTO and more closely reproduces the high-resolution distribution. This behavior explains the larger low-resolution dust scale height in FARGO3D, but the paper does not identify the underlying numerical or physical cause.

References

Why the velocity distributions for FARGO3D are already close to the final distribution remains an open question and needs to be identified with future work.

— A comparison between particle and fluid approaches for streaming instability in global patch simulations  (2610.09575 - Ostertag et al., 7 Oct 2026) in Section 4.3, “Influence of temporal and spatial accuracy”