摘要
以对粉尘云状态参数的定量测定为基础,对玉米粉尘火焰在开口垂直管道中向上传播的过程进行了实验研究.在情形A中,火焰从管道的封闭端向开口端传播,在情形B中,从开口端向封闭端传播.实验中,观察到两种粉尘火焰,即湍流火焰和层流火焰,火焰形态转变对应的点火延迟时间约等于1.1 s,即粉尘云湍流运动强度为10cm/s.情形A中,层流火焰的传播出现周期性振荡现象,湍流火焰在传播过程中不断加速;情形B中,两种火焰都匀速传播,湍流火焰传播速度明显大于层流火焰.在所考察的实验条件下,粉尘浓度对于玉米粉尘火焰传播速度的影响不大.
Based on the quantitative determination of dust cloud parameters, the upward flame propagation through cornstarch dust clouds was investigated in an open vertical duct. Flames propagated from the closed end of the duct to the open end in case A, and from the open end to the closed end in case B. With the increase of ignition delay time, two different kinds of flame were observed in both cases ： turbulent and laminar flames. The transition occurs when the ignition delay time is about 1.1 s, corresponding to a turbulence level of 10 cm/s. In case A, the propagation of laminar flames is periodically oscillatory, and the turbulent flame accelerates continuously. In case B, they all propagate with steady velocity, and the propagation velocity of turbulent flames is much higher than that of laminar flames. For the present experimental conditions, it is found that the flame propagation velocity is a weak function of dust concentration in cornstarch dust clouds.
出处
《燃烧科学与技术》
EI
CAS
CSCD
北大核心
2007年第1期5-9,共5页
Journal of Combustion Science and Technology
基金
中国科学院知识创新工程资助项目(KJCX2-SW-L05)
关键词
粉尘火焰
火焰传播
扬尘方法
扬尘湍流
粉尘浓度
玉米粉
dust flame
flame propagation
dust dispersion process
dispersion-induced turbulence
dust concentration
cornstarch
