中文摘要：

采用挂滴法研究了在高温条件下纳米铝粉质量分数及粒径对乙醇基纳米流体燃料液滴着火特性及燃烧过程的影响.研究结果表明,与乙醇燃料相比,添加50,nm铝粉质量分数为0.5%,和2.5%,的乙醇基纳米流体燃料液滴的着火延迟时间分别降低了0.315,s和0.525,s,着火温度分别降低了12.712,℃和42.214,℃.增大纳米铝粉粒径至100,nm,当添加的铝粉质量分数为2.5%,时,其液滴着火延迟时间比乙醇降低了0.42,s,两种粒径的纳米流体燃料着火温度相近.乙醇及乙醇基纳米流体燃料液滴燃烧火焰分为3个阶段：着火燃烧阶段、火焰熄灭阶段和二次燃烧阶段.随纳米铝粉含量增加,在二次燃烧阶段纳米流体燃料液滴火焰亮点增多,火焰燃烧剧烈,其中含50,nm铝粉的纳米流体燃料比含100,nm铝粉的纳米流体燃料燃烧剧烈.

英文摘要：

The effects of various concentrations and sizes of nano-aluminum powder on the ignition characteristics and burning process of droplets of ethanol-based nanofluid fuels were investigated at high temperature.The results showed that the ignition delay time of droplets of ethanol-based nanofluid fuels containing 0.5%, and 2.5%, nanoaluminum powder with the average size of 50,nm decreased by 0.315,s and 0.525,s,respectively.The ignition temperature decreased by 12.712,℃ and 42.214,℃,respectively.As the average size of nano-aluminum powder increased from 50,nm to 100,nm,the ignition delay time of droplets of ethanol-based nanofluid fuels containing 2.5%, nano-aluminum powder decreased by 0.42,s,while the ignition temperature remained highly similar.The combustion process was divided into three distinctive stages：the ignition combustion stage,the flame extinguishment stage and the secondary combustion stage.With the increase of nano-aluminum powder content,the number of bright spots in the flame increased and the flame burned violently in the secondary combustion stage.The droplets of ethanol-based nanofluid fuels containing 50,nm nano-aluminum powder burned more violently than those of ethanol-based nanofluid fuels containing 100,nm nano-aluminum powder.