Numerical Modeling of Hydrogen Premixed Combustion

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.