The XXXI edition of the Canary Islands Winter School in Astrophysics is dedicated to the Computational fluid dynamics in astrophysics (La Laguna, Tenerife, 19-28 November 2019). The intention of the school is to provide an overview of modern applications of the CFD simulations in the large range of astrophysical regimes (from the solar and stellar interior and atmosphere, the compact objects, the stellar and planetary simulations, to the ISM and galaxies). Full information about the school is available at