The laminar flame characteristics of natural gas-hydrogen-air mixtures were studied in a constant volume combustion bomb under various initial pressures. Laminar burning velocities under different initial pressures and at different equivalence ratios were obtained for natural gas-hydrogen-air mixture with different hydrogen fractions. Flame stability and its relevant factors were also analyzed. The results showed that as hydrogen fraction increases, laminar burning velocity increases, while Markstein length decreases, i.e. flame stability decreases. Under different initial pressures, with the increase of equivalence ratio Markstein length tends to increase at different hydrogen fractions, which shows that flame stability increases. Unstretched flame burning velocity decreases slightly with the increase of initial pressure. The effect of initial pressure and hydrogen fraction on unstretched flame burning velocity was greatest near the stoichiometric equivalence ratio.
|Number of pages
|Ranshao Kexue Yu Jishu/Journal of Combustion Science and Technology
|Published - 1 Jun 2009