Near Field Sonic Boom Simulations for C608 airplane of the Third AIAA SPW by Unstructured/Structured Overset Grid Method

摘要

The 3rd AIAA SPBW (Sonic boom prediction workshop) was held in January 2020, and in the near-field section, the near-field pressure signature of the C608 airplane, an early version of NASA X-59, were compared with all participant's results. The authors have applied the unstructured/structured overset grid method to the C608 airplane. In this method, an unstructured grid is used in the vicinity of the airplane, and the flow field away from the airplane is simulated by overset the structured grid along the shock wave. It is found that even if the near-field of the airframe is a coarse grid, a sharp and a clear near-field pressure signatures can be obtained by using a fine grid in the far distance. In this paper, it describes the detail of unstructured/structured overset grid method and its effects.