Influence of Preheat Temperature on the Laminar Burning Velocity of Methane-Air Mixtures

The influence of preheat temperature on methane-air laminar burning velocity was investigated with a burner tube technique. The measurements were made by varying preheat temperature from 30°C to 600°C, pressure from 0.1MPa to 0.3MPa and equivalence ratio from 1.0 to the fuel-lean measurable limit(>0.5). The laminar burning velocity was determined using the area method visualized with schlieren photography. It shows a strong dependence on preheat temperature and increases proportionally to the approximate square of the preheat temperature at constant pressure. While the increase of pressure decreases the burning velocity, the dependence is relatively small.