Spherical weak blast propagation above a rough periodic surface is investigated by performing numerical simulations of the Euler equations. The study of the reflection pattern shows that waves diffracted by the surface asperities merge to form an effective reflected shock. It is initially detached from the incident shock but gradually catches up with it. If the source energy is sufficient, the reflected shock interacts with the incident one and Mach reflection occurs. Thus, the triple point has a similar trajectory to that over a smooth surface. In addition, the maximal overpressure is shown to be greater for small roughness scales in a layer near the surface. Far from the surface, it is close to that of a smooth surface for small roughness scales and to the free field for the highest ones. The increase in the maximal overpressure is related to oscillations on the waveforms that appear behind the shock. These properties are associated with the existence of a surface wave that propagates along the surface. Comparison of results in the linear regime with an analytic solution confirms this explanation.

通过执行欧拉方程的数值模拟，研究了粗糙周期性表面上方的球形弱爆炸传播。对反射模式的研究表明，被表面凹凸不平的衍射波合并形成有效的反射激波。它最初与事件冲击分离，但逐渐赶上它。如果源能量充足，反射激波与入射激波相互作用，发生马赫反射。因此，三相点的轨迹与光滑表面上的轨迹相似。此外，对于靠近表面的层中的小粗糙度尺度，最大超压显示为更大。远离表面，对于小粗糙度标度，它接近于光滑表面，对于最高粗糙度标度，它接近于自由场。最大超压的增加与出现在冲击后面的波形的振荡有关。这些特性与沿表面传播的表面波的存在有关。线性范围内的结果与解析解的比较证实了这一解释。