The modelling of fire and smoke spread in buildings or in common carriers using CFD methods is computationally very demanding. Three-dimensional turbulent flow with radiative, convective and conductive heat transfer has to be modelled on length scales ranging from less than one millimetre to several hundred metres: The use of high performance computing suggests itself.
One widely accepted software package is the Fire Dynamics Simulator (FDS), an open source project of the National Institute of Standards and Technology (NIST) of the United States in cooperation with VTT Technical Research Centre of Finland. FDS solves numerically a simplified form of the Navier-Stokes equations for buoyant driven flows with low Mach-Numbers on a rectangular grid. It allows Large Eddy Simulations (LES) as well as Direct Numerical Simulations (DNS) and is primarily developed for serial usage. However, the simulation of whole buildings and the geometrical resolution necessary for realistic LES makes parallel calculations inevitable. The effective and correct parallelization is mandatory but complicated due to the strong dynamics of combustion.
Tests with the available parallel version of FDS were conducted on high performance systems with focus on scalability as well as concordance with the serial version. The results have not been satisfying yet but the next major FDS release is already announced. One of the main improvements is going to be the parallelization concept and we are looking forward to testing it as soon as possible.
We are involved in the FDS Usergroup, an organisation of German-speaking users of the Fire Dynamics Simulator, who aims to improve FDS itself as well as its acceptance in the field of Fire Safety Engineering. Remarkably about this group is the combination of scientific and application-oriented perspectives that helps both sides equally.