Splashing characteristics of multiple and single drop impacts onto a thin liquid film

The impact of millimetric drop arrays on solid walls covered by a thin liquid film is studied experimentally by means of CCD camera visualisation and image analysis. The comparison with single drop impacting under the same impacting conditions revealed new features of this complex phenomenon, among them the existence of a third splashing mechanism (after prompt and crown-splashing), in competition with, but less efficient than crown-splashing. Measurements of crown dynamics (height,diameter) and drop size and number are reported.