Massively Parallel DNS of Flame Kernel Evolution in Spark-Ignited Turbulent Mixtures

A parallel code for the direct numerical simulation (DNS) of reactive flows with detailed models for chemical reactions and molecular transport has been used as a benchmark on two large commodity hardware clusters with current state-of-the-art processor and network technologies. Up to 180 Alpha EV68 833 MHz have been used on the first system and up to 400 AthlonMP 1.4 GHz CPUs have been used on the other one. Both clusters comprise dual-nodes and Myrinet-2000 interconnect. The influence of the dual-nodes on the parallel efficiency is discussed and the performance of these clusters is compared with Cray T3E systems. The other part of the paper deals with the application of DNS to study premixed flames emerging after induced ignition of turbulent mixtures. The discussion focusses on the temporal evolution of the heat-release rate. In addition to the analysis of flames expanding in homogeneous turbulent mixtures, first DNS results of a flame kernel evolving in a turbulent mixture with spatial inhomogeneities of the equivalence ratio are presented.