【摘要】 对甲醇预燃室湍流射流引燃甲醇稀氛围气的着火和燃烧过程进行数值模拟研究，分析关键自由基（CH₂O、OH）的时空分布特征。结果表明，预燃室上部点火时，其下部的未燃混合气进入主燃室形成冷射流，射流火焰进入主燃室时沿冷射流快速传播，当火焰接触主燃室底部后发生回流，出现类层流燃烧现象。当主燃室中甲醇当量比从0.8下降到0.6、0.4,燃烧持续期分别增长87.9%和276.9%。在当量比0.4的超稀薄工况下，主燃室下部发生燃烧，上部未被点燃的氛围气被推入预燃室形成逆流。CH₂O主要分布在1500K以下的火焰锋面区域，在主燃室较高当量比下能被完全消耗，而在较低当量比下CH₂O则会大量积累。OH分布在1500K以上的高温燃烧区域，主燃室当量比越高，OH分布越广。综上可见，主燃室0.4超稀薄当量比下预燃室射流点火不成功。更多还原

【Abstract】 Numerical simulation study were conducted on the ignition and combustion processes of methanol in a methanol pre-chamber turbulent jet igniting methanol lean atmosphere, focusing on the spatiotemporal distribution characteristics of key radicals（CH₂O, OH）. The results demonstrated that upon ignition in the upper part of the pre-chamber, unburned mixed gases in the lower part enter the main chamber, forming a cold jet. The jet flame propagates rapidly along the cold jet upon entering the main chamber, and subsequent flame contact at the bottom of the main chamber causes backflow, leading to quasi-laminar combustion. As the methanol equivalence ratio in the main chamber decreases from 0.8 to 0.6 and 0.4, the combustion duration increases by 87.9% and 276.9%, respectively. Under the ultra-lean condition of equivalence ratio 0.4, combustion occurs in the lower part of the main chamber, while unignited atmosphere gases in the upper part are pushed back into the pre-chamber forming backflow. CH₂O predominantly distributes in the flame front region below 1500 K, being fully consumed in the main chamber under higher equivalence ratios, whereas significant accumulation occurs under lower equivalence ratios. OH is distributed in the high-temperature combustion region above 1500 K, with broader distribution observed in the main chamber at higher equivalence ratios. In summary, under the ultra-lean equivalence ratio of 0.4 in the main chamber, unsuccessful ignition of the pre-chamber jet is observed.更多还原