Measurement of laminar burning velocity of propane-air mixtures with nitrogen as the diluent was made at room temperature and atmospheric pressure under different equivalence ratios and dilution ratios based on the spherically expanded flame. The results show that for propane-air mixtures, the un-stretched flame propagation speed and the unstretched laminar burning velocity reach their maximum values at the equivalence ratio of 1.1. Markstein length decreases with the increase of equivalence ratio, indicating the increase in flame instability with the increase of equivalence ratio. For propane-air-diluent mixtures, the burning velocity decreases with the increase of dilution ratio. Markstein length increases with the increase of dilution ratio when equivalence ratio is less than 1.4, and the flame stability tends to increase with the increase of dilution ratio. The ratio of unstretched laminar burning velocity with and without diluent is only related to the dilution ratio and is little influenced by the equivalence ratio. A linear correlation is found between the ratio of unstretched laminar burning velocity with and without the diluent and the dilution ratio.
|Number of pages
|Neiranji Xuebao/Transactions of CSICE (Chinese Society for Internal Combustion Engines)
|Published - 1 Nov 2008