A detailed framework to incorporate dust in hydrodynamical simulations

Dust plays a key role in the evolution of the ISM and its correct modelling in numerical simulations is therefore fundamental. We present a new and self-consistent model that treats grain thermal coupling with the gas, radiation balance, and surface chemistry for molecular hydrogen. This method can be applied to any dust distribution with an arbitrary number of grain types without affecting the overall computational cost. In this paper we describe in detail the physics and the algorithm behind our approach, and in order to test the methodology, we present some examples of astrophysical interest, namely (i) a one-zone collapse with complete gas chemistry and thermochemical processes, (ii) a 3D model of a low-metallicity collapse of a minihalo starting from cosmological initial conditions, and (iii) a turbulent molecular cloud with H-C-O chemistry (277 reactions), together with self-consistent cooling and heating solved on the fly. Although these examples employ the publicly available code KROME, our approach can be easily integrated into any computational framework.