We examine the diffraction dynamics of a two-dimensional (2D) detonation in a circular arc of the conventional HMX-based, high performance, solid explosive PBX 9501, for which the detonation reaction zone length scale is estimated to be of the order of 100–150 µm. In this configuration, a steady propagating detonation will develop, sweeping around the arc with constant angular speed. We report on results from three PBX 9501 arc experiments, exploring the variation in linear speed on the inner and outer arc surfaces for the steady wave along with the structure of the curved detonation front, as a function of varying inner surface radius and arc thickness. Comparisons of the properties of the motion of the steady wave for each arc configuration are then made with a spatially-distributed PBX 9501 reactive burn model, calibrated to detonation performance properties in a 2D planar slab geometry. We show that geometry-induced curvature of the detonation near the inner arc surface has a significant effect on the detonation motion even for conventional high explosives. We also examine the detonation driving zone structure for each arc case, and thus the subsonic regions of the flow that determine the influence of the arc geometry on the detonation propagation. In addition, streamline paths and reaction progress isolines are calculated. We conclude that a common approximation for modeling conventional high explosive detonation, wherein the shock-normal detonation speed is assumed equal to the Chapman–Jouguet speed, can lead to significant errors in describing the speed at which the detonation propagates.

我们研究了基于传统HMX的高性能固体炸药PBX 9501的圆弧内二维（2D）爆轰的衍射动力学，其爆轰反应区长度尺度估计为100量级–150 µm。在这种配置下，将形成稳定的传播爆炸，以恒定的角速度绕弧扫掠。我们报告了来自三个PBX 9501电弧实验的结果，探讨了稳定波的内，外电弧表面上的线速度以及弯曲爆震波前结构的变化，该变化是内表面半径和电弧厚度的函数。然后使用空间分布的PBX 9501无功燃烧模型对每种电弧配置的稳定波运动特性进行比较，在2D平面平板几何中针对爆轰性能特性进行校准。我们表明，即使对于常规的高炸药，内弧表面附近的爆轰的几何形状引起的曲率也对爆轰运动具有重大影响。我们还检查了每种电弧情况下的爆轰驱动区结构，从而确定了决定电弧几何形状对爆轰传播的影响的流的亚音速区域。此外，还计算了流线路径和反应进度等值线。我们得出的结论是，对常规高爆炸起爆进行建模的通用逼近（假定冲击法向起爆速度等于查普曼–乔格特速度）可能会在描述爆炸传播速度时导致重大错误。我们表明，即使对于常规的高炸药，内弧表面附近的爆轰的几何形状引起的曲率也对爆轰运动具有重大影响。我们还检查了每种电弧情况下的爆轰驱动区结构，从而确定了决定电弧几何形状对爆轰传播的影响的流的亚音速区域。此外，还计算了流线路径和反应进度等值线。我们得出的结论是，对常规高爆炸起爆进行建模的通用逼近（假定冲击法向起爆速度等于查普曼–乔格特速度）可能会在描述爆炸传播速度时导致重大错误。我们表明，即使对于常规的高炸药，内弧表面附近的爆轰的几何形状引起的曲率也对爆轰运动具有重大影响。我们还检查了每种电弧情况下的爆轰驱动区结构，从而确定了决定电弧几何形状对爆轰传播的影响的流的亚音速区域。此外，还计算了流线路径和反应进度等值线。我们得出的结论是，对常规高爆炸起爆进行建模的通用逼近（假定冲击法向起爆速度等于查普曼–乔格特速度）可能会在描述爆炸传播速度时导致重大错误。