2025/02/01 by Mark C. Anderson, Kent L. Gee · 2 voices · 1 citation
Engineering · Mathematics · #Computational Fluid Dynamics and Aerodynamics #Fluid Dynamics and Turbulent Flows #Gas Dynamics and Kinetic Theory
paper · doi:10.1121/10.0035649
openalex publication_date 2025/02/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/06/26
When the SpaceX Falcon-9 rocket booster descends through the atmosphere after a launch, it produces a sonic boom with three shocks in the far field, rather than the usual two-shock N-wave. In this Letter, the additional shock's origin is explained using sonic boom theory, nonlinear propagation modeling, computational fluid dynamics, and photographic evidence. The extra central shock results from a forward-migrating compression wave caused by the grid fins merging with a rearward-migrating rarefaction wave caused by the lower portions of the booster, including the folded landing legs.