Unsteady Interaction Between Laminar Propagating Flame and Array of Small Fuel Droplets

层流传播火焰与小燃料液滴阵列之间的不稳定相互作用

基本信息

批准号：
11650233
负责人：
KADOTA Toshikazu
金额：
$ 1.41万
依托单位：
Osaka Prefecture University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2000
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11650233/
关键词：
FUEL DROPLET PROPAGATING FLAME IGNITION VOLATILITY SINGLE DROPLET DROPLET ARRAY BINARY FUEL 伝播火災

项目摘要

An experimental study has been made of the ignition process of fuel droplet array or single fuel droplets subjected to a laminar flat flame propagating through a lean homogeneous propane/air mixture at constant pressure. Binary fuels consisting n-hexane and n-hexadecane or n-dodecane, and benzene and n-hexadecane were tested. Water-emulsified liquids consisting n-dodecane, and pure fuels like n-hexane, n-octane, n-dodecane and n-hexadecane were used as well. A combustion chamber made of a transparent duct was installed with spark electrodes, fine quartz fibers to suspend fuel droplets, and a shutter to allow the burned gas to escape at the top end. A high-speed video camera was provided for photographic observation of each droplet ignited by the propagating flame.Ignition delay of pure-fuel droplets increased monotonically with increase of the initial droplet diameter and decrease of fuel volatility. The influence of the initial droplet diameter on ignition delay decreased with increas … More ing fuel volatility. Ignition delay of the binary-fuel droplets decreased with increase of the volume concentration of the higher-volatility fuel. Ignition delay of the binary fuels showed a minimum and a maximum as a function of the initial droplet diameter. The diameters at the minimum and the maximum of ignition delay decreased with increasing higher-volatility fuel concentration. Ignition delay or emulsified-fuel droplets monotonically with the initial droplet diameter as expected. The increase in the volume concentration of the higher-volatility component caused an inverse result in comparison with that for the binary mixtures of fuels, since the higher-volatility component was water in this case. Part of the propagating flame behind the droplet became convex towards the unburned gas as it passed a droplet or higher-volatility fuels, while the flame remained flat for the lower-volatility fuels. The deformation length of the propagating flame behind the droplet increased with increasing higher-volatility fuel concentration. Less

对燃料液滴阵列或单个燃料液滴的点火过程进行了实验研究，该火焰在恒定压力下通过贫均质丙烷/空气混合物传播，由正己烷和正十六烷或正己烷组成。 - 测试了十二烷、苯和正十六烷，由正十二烷组成的水乳化液体，以及正己烷等纯燃料。还使用了正辛烷、正十二烷和正十六烷。由透明管道制成的燃烧室安装有火花电极、悬浮燃料液滴的细石英纤维和允许燃烧后的气体逸出的百叶窗。顶端设置有高速摄像机，用于对传播火焰点燃的每个液滴进行摄影观察。纯燃料液滴的点火延迟随着初始液滴直径的增加和直径的减小而单调增加。初始液滴直径对点火延迟的影响随着二元燃料挥发性的增加而减小。二元燃料液滴的点火延迟随着高挥发性燃料的体积浓度的增加而减小。显示了作为初始液滴直径的函数的最小值和最大值，点火延迟的最小和最大直径随着较高挥发性燃料浓度的增加而减小。正如预期的那样，与初始液滴直径单调地变化，与燃料的二元混合物相比，高挥发性组分的体积浓度的增加导致了相反的结果，因为在这种情况下，高挥发性组分是水的一部分。当液滴经过液滴或挥发性较高的燃料时，液滴后面的传播火焰会向未燃烧的气体凸出，而对于挥发性较低的燃料，火焰保持平坦。液滴后面传播的火焰随着高挥发性燃料浓度的增加而增加。