The project SIMAC (Simulation of Ignition Mechanisms in Annuar multi-injectors Combustors and comparison with experiments) carried out by CERFACS and EM2C was selected by PRACE among the 8 success stories in the 2014 annual report (http://www.prace-ri.eu/ar-2014/). For the very first time, Large Eddy Simulation of the ignition of an annular combustion chamber has been validated in details by comparison with measurements of ignition in a transparent annular burner at EM2C (MICCA). Ignition being critical in the design of more efficient aeronautical burners, the results of this project will be used to improve the capacity of ignition and re-ignition of future burners.