Elucidation and Modeling on Unsteady Combustion Behavior of Heterogeneous Fuel System

研究了分离液滴对醇类和碳氢化合物的非稳态燃烧行为，重点研究了燃料性质、环境组分和碳烟对非稳态燃烧的影响。乙醇在空气中的燃烧表现出准稳态行为，水凝结到液滴中的影响很小。随着沸腾温度的升高，正丁醇的燃速有逐渐增大的趋势。煤烟燃料的燃速明显地呈不稳定的递增趋势。高浓度的环境二氧化碳抑制了碳烟的产生，并导致了不稳定行为的缓解。另一方面，高浓度的Ar促进了碳烟的生成，并促进了非稳态行为。阐明了烟尘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.