中文摘要：

利用定容燃烧弹研究了不同初始温度和初始压力下的天然气燃烧特性，分析了初始温度、初始压力和当量比对其燃烧过程的影响。研究结果表明：随着初始温度的升高（300-450K），天然气质量燃烧速率明显增加，燃烧持续期和火焰发展期显著缩短。随着初始压力的升高（0．1—0．75MPa），天然气质量燃烧速率明显减慢，燃烧持续期和火焰发展期显著增长。且稀混合气和浓混合气条件下初始温度和初始压力的变化对燃烧持续期和火焰发展期的影响更明显。

英文摘要：

The combustion characteristics of natural gas are studied in a constant volume bomb at various equivalence ratios, initial temperature and pressure. The study shows that with an increase of initial temperature, the normalized mass burning rate increases and the flame developing duration and combustion duration decrease. With an increase of initial pressure, the normalized mass burning rate decreases obviously, the flame developing duration and combustion duration increase at various equivalence ratios. For both lean and rich combustion, the effects of initial temperature and pressure on combustion duration are quite obvious.