Physical Mechanisms for Near-Field Blast Mitigation With Fluid Containers

A description of the current state of understanding of the physical mechanisms responsible for near-field blast mitigation with fluid containers is presented in this chapter. From an applications perspective, the benefits of using fluid-filled containers for blast protection are significant with reductions in the dynamic deformation of a steel target of 50%. Experiments are presented that highlight the importance of the container geometry on the mitigation provided. The experimental data is combined with numerical simulations to identify some of the key mitigation mechanisms responsible for blast mitigation with fluid containers. Shadowing, rarefaction waves, and mitigant mass all have an influence on the target response. In addition to the presence of mitigation mechanisms, the containers also reduce the standoff to the charge and hence their geometry affects the input loading to the system. The trade-offs between these mitigation and loading mechanisms results in an optimum width of container for a given loading scenario. While significant progress has been made to understand the mechanisms for near-field blast mitigation with fluid containers, there are still a number of areas where further knowledge is required. Spreading of the fluid was observed in addition to the formation and collapse of cavitation bubbles. It is suggested that future work focus on quantifying the relative importance of each of the mitigation mechanisms.