【摘要】 在一透明有机玻璃块上钻孔,填满延期药(铅丹∶硅=85∶15),在一端安装电极,置于一耐压钢质容器内,容器压力可在实验前充气调节,可认为延期药燃烧时容器内压力恒定。高速摄影仪记录燃烧波阵面移动过程,观察发现,燃烧波阵面向前传播线速度不是定值,而是有节奏的"闪烁"跃进。亮时前进速度较快,暗时则较慢。通过计算图片张数得到小区间燃烧速度,对比发现燃烧速度是脉动的,脉动周期宽度约为1.0 mm,时间约14 ms。分析认为:脉动原因是加热区热分解产生的气体膨胀,使正在燃烧的延期药位移产生裂隙,其阻碍了加热区加热,使燃速降低,所以产生燃烧脉动;脉动周期不稳定的原因是火药密度不均或混药不均。通过改变预设压力,使延期药在不同压力下燃烧,对比发现,随着压力增大,燃烧速度呈一次线性加速。更多还原

【Abstract】 To disclose the pulse combustion mechanism of delay composition,the high-speed camera was used to record the propagation process of combustion wave front.The propagation velocity was observed to be not constant but rhythmic " flashing" leaps.The combustion rate between short intervals of photos was obtained by calculation.The comparison showed that the combustion rate was pulsatile,and pulsation cycle was 1.0 mm wide with 14 ms in time.The analysis showed that the cause of pulse was gas expansion of thermal decomposition in heated area when the burning delay composition was shifted.Crack of displacement hindered the heating process and slowed the burning rate,so the pulse combustion was generated.The reason for unsteady pulsation cycle was due to the uneven composition density or mixing.Delay composition could burn under different conditions by changing the preset pressure.The combustion rate linearly accelerated as the pressure increased.更多还原