Nearfield Summary and Statistical Analysis of the Second AIAA Sonic Boom Prediction Workshop

A summary is provided for the Second AIAA Sonic Boom Workshop held on January 8-9, 2017, in conjunction with AIAA SciTech 2017. The workshop used four models of increasing complexity: an axisymmetric body, a wing-body, and a wing-body with tail configuration with either flow-through nacelles or propulsion boundary conditions. The last configuration was optional. The models were designed with similar nearfield signatures to isolate geometry and shock/expansion interaction effects. These cases are more relevant to vehicles with lower ground loudness and have the potential for lower annoyance than those in previous workshops. Eleven international participant groups submitted nearfield signatures. In addition, noise levels were computed by propagating the nearfield signatures to the ground. This allowed the evaluation of grid convergence and statistical distribution with respect to the noise metric. Prediction dramatically improved for the wing-body with tail and flow-through nacelle case between the first and second workshops. The models for the second workshop with quieter ground noise levels than those in the first workshop exposed weaknesses in analysis, particularly in convective discretization. While progress is documented since the first workshop, improvement to the analysis methods for a possible subsequent workshop is also provided.