Granular Jets

With my former PhD student Amy Q. Shen, now at Washington University in St. Louis, we have discovered a granular jet which appears after the impact of a solid sphere onto a deep layer of granular material.  This phenomena is similar to the well-known Worthington jets, which occur when a drop impacts onto a pool of liquid.

The aim of this work is to understand the constitutive relations for rapidly flowing granular media, by comparing the dynamics of this jet to the dynamics of the Worthington jet.

The images on the right are taken with a regular video camera and a high-speed flash to freeze each field of the video frames.