The Third AIAA Sonic Boom Prediction Workshop was held in January 2020, and in the near-field section of the workshop, several simulated near-field pressure signatures of the C608 airplane, an early version of the NASA X-59, were compared. The authors have applied the unstructured/structured overset grid method to the C608 airplane case. In this method, an unstructured grid is used in the vicinity of the airplane, and the flowfield at several body lengths away from the airplane is simulated by oversetting a structured Mach cone aligned grid with the unstructured grid. It is found that the near-field pressure signatures can be obtained accurately with sharp pressure jumps in the signature by using a fine structured grid in the midfield even when a relatively coarse unstructured grid is used in the near-field of the airplane. The results show that the unstructured/structured overset grid method is a way to obtain accurate near-field pressure signatures for sonic boom estimation efficiently.

第三届 AIAA 音爆预测研讨会于 2020 年 1 月举行，在研讨会的近场部分，对 NASA X-59 的早期版本 C608 飞机的几个模拟近场压力特征进行了比较。作者已将非结构化/结构化重叠网格方法应用于 C608 飞机案例。在该方法中，在飞机附近使用非结构化网格，通过将结构化马赫锥对齐网格与非结构化网格重叠来模拟远离飞机的几个机身长度处的流场。发现即使在飞机的近场中使用相对粗糙的非结构化网格时，通过在中场使用精细结构化网格，也可以准确地获得近场压力特征，并在特征中出现急剧的压力跳跃。