综合管廊燃气舱燃气爆炸冲击波传播特征研究*

为研究综合管廊燃气舱燃气爆炸冲击波的传播特征，采用数值模拟方法研究首次超压峰值和首次流速峰值的变化规律，建立首次流速峰值与首次超压峰值和填充长度的耦合关系，分析不同填充长度情况下燃气爆炸后的超压和水平流速的变化规律。结果表明:燃气爆炸后，燃气舱内存在多个超压峰值，峰值间存在明显的时间差。冲击波到达各测点的时间与燃气填充长度成反比关系。水平流速曲线随着时间的变化以0为基点上下振荡，存在正向峰值和反向峰值。随着燃气填充长度的增加，流速下降趋势变快。首次超压峰值随传播距离的增加先增大后减小再增大，随着填充长度的增加，产生超压峰值最大值的位置由接近填充长度结束的位置转移到燃气舱封闭端。首次流速峰值随传播距离的增加先增大后减小。首次流速峰值与首次超压峰值呈现正比关系，通过拟合得到流速峰值与超压峰值及填充长度的耦合关系。研究结果可为燃气舱燃气爆炸后的流速分布研究以及燃气舱防火分区的设计提供参考。

Study on propagation characteristics of gas explosion shock wave in gas cabin of utility tunnel

In order to study the propagation characteristics of gas explosion shock wave in the gas cabin of utility tunnel,the numerical simulation method was used to study the change laws of the first peak overpressure and the first peak flow velocity,then the coupling relationship among the first peak flow velocity,the first peak overpressure and filling length was established,and the change laws of overpressure and horizontal flow velocity after gas explosion under different filling lengths were analyzed.The results showed that after the gas explosion,there existed multiple peak overpressures in the gas cabin,and there was an obvious time difference between the peaks.The time for the shock wave to reach each measuring point was inversely proportional to the gas filling length.The horizontal flow velocity curve oscillated up and down with 0 as the base point with time,and there were the positive and reverse peaks.As the gas filling length increased,the descending trend of flow velocity became faster.The first peak overpressure increased first,then decreased and then increased with the increase of propagation distance.With the increase of filling length,the position of the maximum peak overpressure shifted from the position close to the end of filling length to the closed end of gas cabin.The first peak flow velocity increased first and then decreased as the propagation distance increased.The first peak flow velocity and the first peak overpressure presented a proportional relationship.The coupling relationship among the peak flow velocity,the peak overpressure and the filling length was obtained by fitting.The research results can provide reference for the research on the flow velocity distribution after the gas explosion in the gas cabin and the design of fire compartment in the gas cabin.