This is a continuation of Fire Modelling (SNIC 2020/12-14) but a new proposal due to staff changes. CFD simulation in the fire research area have been increasing substantially the recent years. From applications to single CPU units in the beginning the area has moved into use of multigrid calculations which are suitable for cluster calculations. Several research projects as well as PhD projects have been using cluster simulations at the Aurora clusters. An important aspect with this respect is the validation of the CFD codes by means of experiment in which large resources of computer resources are necessary. Also connection of CFD simulations with advanced evacuation models are necessary.