中文摘要：

基于流体力学计算理论,对20 L球形密闭容器内铝粉扩散和爆炸过程进行了数值模拟。通过改变点火延迟时间和粉尘浓度,研究了湍流对不同浓度铝粉爆炸特性的影响。研究结果表明：点火延迟时间对铝粉爆炸的最大爆炸压力和最大爆炸压力上升速率影响较大,且存在最佳点火延迟时间,此时最大爆炸压力取最大;随着容器内铝粉浓度的增大,最佳点火时间先增大后保持不变,故单一的点火延迟时间并不能真正地反映不同浓度粉尘的爆炸威力;湍流强度和粉尘云分布对最大爆炸压力和最大爆炸压力上升速率都存在影响,粉尘云分布的均匀程度对最大爆炸压力的影响要强于湍流强度;湍流强度对最大爆炸压力上升速率的影响要强于粉尘云的分布。

英文摘要：

The dispersion and explosion processes of aluminum dust in 20 L spherical confined chamber are numerically simulated based on computational fluid dynamics theory. The influence of turbulence intensity on the explosion characteristics of aluminum dusts with different concentrations at various ignition delay times is studied. The results indicate that the ignition delay time has a significant effect on maximum explosion pressure and maximum rate of pressure rise of aluminum dust explosion,and there exists an optimum ignition delay time for pmax. With the increase in the concentration of aluminum dust in the chamber,the optimum ignition delay time increases first and then remains unchanged,therefore a single ignition delay time cannot accurately reflect the explosion powers of aluminum dusts with different concentrations. Both turbulence intensity and distribution of dust cloud have the influences on maximum explosion pressure and maximum rate of pressure rise. The uniformity of dust distribution has a greater effect on maximum explosion pressure than the turbulence intensity,while the turbulence intensity has a greater effect on maximum rate of pressure rise than the uniformity of dust distribution.