矿山巷道转弯处冲击波紊流区的数值模拟研究

爆炸空气冲击波的研究是弹药等武器作战效能评估的重要依据，也是对矿井爆炸事故的系统安全性进行分析的基础。爆炸空气冲击波在通过巷道转弯处时，受到巷道壁面的约束而产生反射及叠加，形成冲击波紊流区，将打乱了冲击波能量在巷道内的分布，而后会在传播一定距离后恢复为“平面波”。利用LS-DYNA数值模拟计算程序，对某一弱冲击波通过不同角度的转弯巷道的情况行了数值模拟，找寻转弯巷道之后的冲击波紊流区的规律及特点。通过对数值模拟结果的研究分析，采用超压比准则及冲量比准则重新量化定义了“平面波”；研究结果表明，冲量准则能更好的定义“平面波”，在转弯角后5倍巷道直径的距离冲击波确定恢复为平面波，在20°、45°、90°、135°四种情况下冲击波的冲量衰减系数分别为0.993 7、0.955 9、0.911 5、0.816 7，紊流区内的最大峰值超压可根据文中的拟合公式进行估算。

Research on the Shockwave Turbulence Area inside the Bend Tunnel by Numerical Simulation

The research of explosive shockwave can be significant for the weapon's damage efficiency evaluation, and also important for measuring the system security in mine explosive accidents.  When propagating through the bend tunnel, due to the limitation of rough wall, the explosive shockwave will produce reflection and superimposition to form a turbulence area, disturbing the energy distribution inside the tunnel. And the shockwave will recover to become “plane” in certain distance. In this paper, LS-DYNA software is utilized to simulate certain weak shockwave propagating through the bend tunnel and to find out the rule and characteristic of shockwave turbulence area inside the bend tunnel. The “plane wave” is quantitatively redefined using the overpressure/momentum ratio benchmarks by analyzing the numerical simulation results. The research result shows that the momentum ratio benchmark can be used to better define the “plane shockwave”, and the shockwave will assuredly recover to become plane in a distance of 5 times equivalent tunnel diameter behind the tunnel bending. In case of a bend corner angle  of 20°,45°,90°or 135°, the momentum attenuation coefficient is 0.993 7, 0.955 9, 0.911 5 or 0.816 7 correspondingly. The max peak overpressure inside the turbulence area can be estimated using the fitting formula listed in the paper.