管道内爆炸波的加速衰减研究

Blast waves generated by the explosions can destroy the equipments and human body during their propagation within the ducts. Therefore, the generation mechanism and their prevention methods are the active research fields，especially, in recent years, due to the frequent occurrence of various explosions and the successful application of fuel air bomb in military, the importance of performing investigations to prevent and suppression explosives are made clearly.So far some relative prevention methods are focused on the use of water mist, venting and blast separation etc. In addtion, previous researches show that, the interaction of blast waves with obstacles can attenuate its intensity promptly under certain conditions. Based on above phenomena, in this project, we investigate the interaction mechanism of blast waves with obstacles, and propose for the modification of obstacle shapes and their arrangments to achieve the accelerating attenuation of blast wave intensity, then suppress the explosion hazards. We plan to combine the methods of experiments, theoretical analyses and numerical simulations, to study firstly the wave structures generated during the process of blasts passing the obstacles, and discuss their effects on the intensity of blast wave fronts. With the design of obstacle shape and arrangement, the desired wave strucutres can be generated and can also attenuate the blast wave during their interactions. The investigations in this field not only have important industrial and military application background, but also involve the intersection fields of subjects of fluid dynamics and explosion & shocks etc., which are the applications of passive flow control methods to the fields of explosions, therefore, there are also of important scientific values.

爆炸过程产生的爆炸波在坑道内传播时会对人及相关设备产生伤害。因而其产生机理与防治方法一直是相关行业的研究热点，特别是近年来各种爆炸事故频繁爆发以及军事中燃料空气炸弹的研制成功，更表明对其研究的重要性。目前相关防治方法研究主要集中在水雾抑爆，泄爆与隔爆等方面。另外，初步研究表明，爆炸波与壁面障碍物相互作用在一定条件下可导致其衰减。基于此，本项目研究爆炸波与障碍物的相互作用机理，提出通过改变障碍物形状及其分布方式，实现爆炸波在管内的加速衰减，达到控制爆炸灾害的目的。本项目拟综合实验、理论分析与数值模拟，从研究爆炸波与障碍物作用产生的各种波系着手，探讨它们对爆炸波的波阵面强度影响，通过设计障碍物形状与分布方式产生所需要的波系结构，使爆炸波强度加速衰减。本项目的研究不仅具有重要的工业与军事应用背景，还涉及流体与爆炸冲击等学科交叉领域，是流体被动控制方法在爆炸领域的应用，因而还具有一定的科学价值。

本项目按项目申请书所提研究内容，开展了爆炸波与障碍物相互作用的研究，探讨爆炸波与障碍物的相互作用及其衰减机理，得到了具有最佳爆炸波衰减效果的障碍物形状。研究表明，入射激波与障碍物作用时，在其迎风面上产生反射激波，随后在障碍物背风面发生弯曲绕射产生对应的膨胀波，同时诱导产生主旋涡。入射激波的衰减取决于反射激波和膨胀波与它的相互作用。反射激波使入射激波的强度增加，而膨胀波则使其压力降低，从而导致激波衰减。入射激波在斜率为负的迎风面上衰减较快，得到了具有最佳衰减效果的迎风三角形模型(2014, Shock waves)，与实际应用中最常用的矩形障碍物的多障碍物对比表明，此三角形模型对激波强度的衰减效果远远优于矩形障碍物。本研究成果对减少爆炸过程产生的危害以及有效保障灾害现场中的人员与财产安全具有极其重要的意义。