DNS of Turbulent Premixed Flames and Heat Transfer in a Constant Volume Vessel

Three-dimensional direct numerical simulation (DNS) of turbulent hydrogen-air premixed flames in a constant volume vessel at relatively high Reynolds numbers have been conducted considering detailed kinetic mechanism and temperature dependence of the transport and thermal properties. The flame behavior and heat transfer characteristics are investigated in the vessel. The flame is strongly affected by the growth of the internal pressure which is caused by the temperature rise in the vessel. Since the pressure increase makes the flame thickness thin, the heat release rate of each flame element is augmented. The local pressure rise due to the dilatation also enhances turbulence and finer scale vortices appear, which make the flame surface more complicated and result in an increase of the flame surface area. Due to the increase of the mean pressure in the vessel, the maximum wall heat flux induced by the flame front is enhanced during the combustion.