Elucidation and Modeling on Unsteady Combustion Behavior of Heterogeneous Fuel System

研究了醇类和碳氢化合物在孤立液滴中的非稳态燃烧行为，重点考察了燃料性质、环境组分和碳烟对液滴非稳态燃烧的影响。乙醇在空气中的燃烧表现出准稳态的燃烧行为，水滴凝结的影响很小。沸腾温度越高的正丁醇，其燃速越快。清楚地观察到了一个不稳定的逐步增加的燃烧速率的炭黑燃料。高浓度的环境二氧化碳抑制了烟尘的产生，并导致非稳态行为的缓解。另一方面，高浓度的氩气促进了碳烟的生成，也促进了非稳态行为。阐明了炭黑和环境因素对非稳态燃烧行为的影响。

Unsteady combustion behaviors of the isolated droplet for alcohols and hydrocarbons were investigated and the effect of fuel properties, ambient components and soot were focused upon. Ethanol combustion in air showed a quasi-steady behavior and a weak effect of the water condensation into the droplet. N-buthanol with a higher boiling temperature shows a gradual increasing trend of the burning rate. An unsteady stepwise increase in the burning rate for sooting fuels were clearly observed. High concentrations of ambient carbon dioxide suppress the soot production and it results in a mitigation of the unsteady behavior. On the other hand, high concentrations of argon enhances the soot production and the unsteady behavior was also promoted. The effect of sooting and ambient factors on the unsteady burning behaviors were clarified.