ABSTRACT
In the present paper, we study the stability of a granular surface submitted to a circular fluid flow. Studying the geometry of the patterns created at the sand/water interface as well as the first stage of their formation allows us to emphasize the interaction between the fluid flow and the sand bed. In the next section, the experimental setup is described. In Section 3, the different kinds of patterns are presented and explained. Then, in Section 4, the first stage of the ripple formation is experimented. Eventually, a summary of our findings is given in Section 5.
