【摘要】 通过利用高速摄像机对液滴燃烧时火焰和粒径的实时测量,以及激光诱导白炽光(LII)对碳烟体积分数的测量方法,研究了垂直电场作用下正癸烷液滴在重力场中的燃烧特性,结果表明:当V>0时,随着电压的增加,液滴上半部分的火焰高度不断缩短,下半部分不断被拉长,在电压为5,kV左右时,火焰呈上下对称结构,燃烧速率常数随着电压的增加先减小后增大,碳烟体积分数随着电压的增加先减小后增大再减小;当V<0时,燃烧速率常数随着电压的增加而增大,碳烟体积分数随着电压的增加逐渐减小;燃烧速率常数随电压的变化是由于碳烟颗粒与外加电场的相互作用而造成的,碳烟颗粒向周围环境的辐射换热量的减少是造成燃烧速率常数增大的主要原因.更多还原

【Abstract】 In this paper,by adopting the laser-induced incandescence(LII)on soot volume fraction measurement method,and by using high speed camera to measure combustion flame and droplet size,the combustion behavior of n-decane droplet in vertical electric field in gravity field is studied.The experimental results show that,when V>0,as voltage increases,the flame height above the droplet center is continuously shortened,while that of the bottom part is stretched;at the voltage of 5,kV,the flames of the upper and bottom parts form a symmetrical structure;with the increase of voltage,the burning rate constant first decreases and then increases,and soot concentration first decreases and then increases and finally decreases again.When V<0,burning rate constant increases with voltage;soot concentration decreases with the increase of voltage;the change of burning rate constant with voltage is mainly due to the interaction of soot particles with the applied direct current electric field,and the reduced radiation heat of soot particles to the ambient environment is the main reason for the decrease of burning rate constant.更多还原