ABSTRACT
The scarcity of oil and gas resources through the whole world put the scientific
community in a challenge to secure an alternative source of fuel. The tendency to go
for hydrogen as a clean fuel and an energy carrier brings in safety issues that have
to be addressed before any wide consent can be achieved. In this regard, availability
of accurate modelling techniques is very useful. This paper presents Large Eddy
Simulations (LES) as a modelling technique for 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 combined
with the fractal analysis of the flame front structure, is employed 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
understanding different combustion phenomena like explosion hazards, internal
combustion engines and gas turbine combustors. The results obtained with the
DFSD model compare well with published experimental data. A detailed analysis is
planned for further validation for the LES-DFSD model for different flow geometries
with hydrogen combustion.