微型定容燃烧腔内C2~C4烷烃/空气火焰传播

在直径35 mm、高度2 mm光学可视的定容燃烧腔内，实验研究了常温常压静止乙烷/空气、丙烷/空气和正丁烷/空气预混气在燃烧腔中心由电火花点燃后向外传播的火焰传播特性。结果表明：3种燃料空气混合气可形成火焰传播的当量比范围不同，范围由大到小排序为乙烷>丙烷>正丁烷；3种燃料均存在由光滑火焰面向褶皱火焰面转变的传播形态；在微型定容燃烧腔内，3种燃料的火焰传播速度均低于常规尺度下定容燃烧弹内火焰传播速度，且火焰传播速度随半径增加而减小；随着当量比增加，火焰锋面容易出现褶皱和断裂现象，在高当量比情况下，火焰传播会出现短暂停滞。

Flame propagation of C2-C4 hydrocarbons/air mixture in a constant-volume micro-chamber

At ambient temperature and pressure condition, the outwardly propagating characteristics of quiescent ethane/air, propane/air and n-butane/air flames were experimentally investigated in a visible constant-volume micro-chamber with 35 mm diameter and 2 mm height respectively. The results showed that the flammable equivalence ratio ranges of these three fuels were different in the micro chamber. The sequence of them was ethane >propane >n-butane. Both smooth flame-front and wrinkled flame-front shapes were observed during flame propagating of these fuels. The flame speed was lower in the micro chamber than that in conventional combustion chamber, and the flame speed declined along the radial direction during flame propagating. With the increase of equivalence ratio, the flame-front was prone to appear wrinkles and crack. In addition, at high flammable equivalence ratio, sometimes, the flame propagation had a brief stagnation.