English

Spatial structure of shock formation

Fluid Dynamics 2017-05-24 v1 Mathematical Physics math.MP

Abstract

The formation of a singularity in a compressible gas, as described by the Euler equation, is characterized by the steepening, and eventual overturning of a wave. Using a self-similar description in two space dimensions, we show that the spatial structure of this process, which starts at a point, is equivalent to the formation of a caustic, i.e. to a cusp catastrophe. The lines along which the profile has infinite slope correspond to the caustic lines, from which we construct the position of the shock. By solving the similarity equation, we obtain a complete local description of wave steepening and of the spreading of the shock from a point.

Keywords

Cite

@article{arxiv.1701.00532,
  title  = {Spatial structure of shock formation},
  author = {J. Eggers and T. Grava and M. A. Herrada and G. Pitton},
  journal= {arXiv preprint arXiv:1701.00532},
  year   = {2017}
}
R2 v1 2026-06-22T17:39:34.113Z