High‐Speed Impact between a Liquid Drop and a Solid Surface

The dynamics of high‐speed impact between a compressible liquid drop and a solid surface are reviewed. Previous estimates for the maximum impact pressure have been based on one‐dimensional approximations. This paper presents a two‐dimensional approximation, adapted from a closely related analysis of the oblique impact between two solid plates. This is valid only for the ``initial'' phase of the impact during which the expanding shock front generated by the impact still remains attached to the target surface, and no lateral outflow takes place. The derivations assume a linear relationship between shock velocity and particle velocity change across the shock front. Numerical results are presented for water and sodium, and can be generalized as follows: The contact pressure remains substantially equal to the one‐dimensional pressure until the contact angle φ at the edge has reached about half of its critical value, at which the assumed model beaks down and lateral outflow must initiate. As this critical condi...