The XXXI Canary Islands Winter School of Astrophysics, organized by the Instituto de Astrofísica de Canarias (IAC), focusses on Computational Fluid Dynamics in Astrophysics. The school, to be held in San Cristóbal de La Laguna (Tenerife, Spain) from 19 to 28 November 2019, will admit about 60 PhD students and young Post-Docs. In a relaxed environment, the school will give participants the opportunity to learn from world-renowned specialists about the techniques used in astrophysics in the modelling of fluid dynamics. Participants of the Winter School will have the opportunity to highlight their current work by presenting a poster. The duration of the school, including the visits to the observatories, is equivalent to a total of 48 hours (5.0 academic credits). Deadline for both registration and application is 30 June 2019 (15 June 2019, if applying for financial support).