In this work, we present a hydrocode Pagosa and explore the Richtmyer-Meshkov Instability (RMI) at an air/high explosive (HE) interface for the first time that is important but has not received much attention yet in the high explosive safety field. Thus, the presented Pagosa can be expected to predict the whole deflagration-to-detonation transition (DDT) process in future. In Pagosa, spatial discretization is implemented on cubic staggered grids by computing different variables at the vertex and the cell center, respectively, a special operator-splitting technique is employed to reduce the computational cost, and an artificial viscosity is added to handle the discontinuous shock waves in our simulations. To quantitatively evaluate the capability of Pagosa to solve these kinds of instabilities, the single mode Rayleigh-Taylor instability (RTI) and the multimode RMI at an air/SF₆ interface are first performed, respectively. The Pagosa results are compared with the related numerical solutions in the existing references and the experimental result. Moreover, a theoretical derivation of growth of RTI is also provided based on our numerical method. Subsequently, we explore the multi-mode RMI at an air/HE interface as well as the effects of several factors using Pagosa. Numerical results show that Pagosa is a powerful toolset to generate the right structures and the amplitude of RTI and RMI at an air/SF₆ interface. The solid HE can be penetrated by a strong shock wave and forms RMI deformations. The RMI at an air/HE interface behaves very different than at an air/SF₆ interface, periodic, decreased oscillation is observed due to material character, and is very sensitive to the initial simulation settings, that is, a tiny change in physical quantities will lead to a remarkable RMI structure, which is also observed in a shock bubble interaction [41]. The findings in this work are significant, and will present a new insight for the high explosive field.

在这项工作中，我们提出了一个水文 Pagosa，并首次探索了空气/高爆 (HE) 界面处的 Richtmyer-Meshkov 不稳定性 (RMI)，这很重要，但在高爆安全领域尚未受到太多关注。因此，所提出的 Pagosa 可以预期在未来预测整个爆燃到爆轰过渡 (DDT) 过程。在 Pagosa 中，通过分别计算顶点和单元中心的不同变量，在立方交错网格上实现空间离散化，采用特殊的算子分割技术来降低计算成本，并添加人工粘度来处理不连续冲击我们模拟中的波浪。为了定量评估 Pagosa 解决此类不稳定性的能力，_{首先分别执行6个}界面。将 Pagosa 结果与现有参考文献中的相关数值解和实验结果进行了比较。此外，基于我们的数值方法，还提供了RTI增长的理论推导。随后，我们使用 Pagosa 探索了空气/HE 界面上的多模 RMI 以及几个因素的影响。数值结果表明，Pagosa 是一个强大的工具集，可以在空气/SF ₆界面生成正确的结构以及 RTI 和 RMI 的幅度。固体HE可以被强冲击波穿透并形成RMI变形。空气/HE 接口的 RMI 与空气/SF _{6的行为非常不同}界面，由于材料特性，观察到周期性的，减少的振荡，并且对初始模拟设置非常敏感，即物理量的微小变化将导致显着的 RMI 结构，这在冲击泡相互作用中也观察到[ 41]。这项工作的发现意义重大，将为高爆领域提供新的见解。