粉尘火焰加速现象的实验研究

EXPERIMENTAL STUDIES ON THE PHENOMENA OF DUST FLAME ACCELERATION

粉尘火焰的发生、加速及由爆燃向爆轰转捩的机理是个至今尚未弄清的问题。需要解决的技术关键之一是在实验室实现弱点火条件下的粉尘火焰加速直至达到爆轰状态。着手发展了一种球形喷粉扬尘装置，令产生的扬尘湍流在水平实验管中形成空间均匀分布和维持秒级悬浮的粉尘云状态。采用以上扬尘装置的水平实验管，在６ｇ黑火药的六点平面点火条件下获得了微细铝粉火焰经５ｍ长的传播过程加速至１０００ｍ／ｓ的实验结果。给出了扬尘湍流强度、粉尘粒度与浓度、点火能量及方式等因素对粉尘火焰加速过程中所起作用，及变截面效应（由小变大）对粉尘火焰减速的影响。

The mechanism of dust flame acceleration and transition to detonation has not yetbeen understood.A Pnuematic spherical dispersion system for obtaining a good quality uniformdust suspension in a horizontal dust combustion tube was developed.A combustion tube for stud-ies of fine aluminum dust flame acceleration and transtiton to detonation under conditions of weakplanar ignition was constructed in the course of the present study,The fine aluminum flame prop-agation velocity approaches 1000m/s at a distance of 5m from the ignition plate. The effect ofdispersion turbulence intensity,dust particle diameter,dust concentration,ignition energy andpattern on flame acceleration has been investigated.The influence of the test tube with varisizedcrosssection on the flame propagation has been examined.