Combustion of low-calorie gases under low exergy loss conditions: Development of combustors based on the international safety standards

本文以CH_4/O_2/CO_2混合气体为研究对象，研究了蜂窝火焰的前沿形状和波动规律。 随着当量的减小，胞宽和胞深逐渐变大，这是由于扩散热不稳定性的增强。 此外，我们对亮度波动进行了时间序列分析。 得到的吸引子类似于环面，且在低当量比时轨迹复杂。 此外，我们进行了数值模拟，研究三维细胞锋的特性。 随着未燃烧气体温度的升高，生长速率增加。 另一方面，由于热膨胀效应的减弱，细胞前缘的形状变得更加平滑。

We treated CH4/O2/CO2 mixtures to study the front shape and fluctuation of cellular flames. As the equivalence decreased, the cell width and cell depth became larger, which was due to the high intensity of diffusive-thermal instability. In addition, we performed the time series analysis on the brightness fluctuation. The obtained attractors were similar to the torus, and the trajectory was complicated at low equivalence ratios. Moreover, we performed numerical simulation to study the characteristics of three-dimensional cellular fronts. As the unburned-gas temperature became higher, the growth rate increased. On the other hand, the shape of cellular fronts became smoother, which was due to the weakness of thermal-expansion effects.