Large eddy simulation of hydrogen-air propagating flames

The future use of hydrogen as a clean fuel and an energy carrier brings in safety issues that have to be addressed before community acceptance can be achieved. In this regard, availability of accurate modeling techniques is very useful. This paper presents large eddy simulations (LES) of propagating turbulent premixed flames of hydrogen-air mixtures in a laboratory scale combustion chamber. A Dynamic flame surface density (DFSD) model where the reaction rate is coupled with the fractal analysis of the flame front structure, is implemented and tested. The fractal dimension is evaluated dynamically based on the instantaneous flow field. The main focus of the current work is to establish the LES technique as a good numerical tool to calculate turbulent premixed hydrogen flames having an equivalence ratio of 0.7. Developing this capability has practical importance in analyzing explosion hazards, internal combustion engines and gas turbine combustors. The results obtained with the DFSD model are compare well with published experimental data. Further investigations are planned to examine and validate the LES-DFSD model for different flow geometries with hydrogen combustion.