ADHESION OF DROPLETS ON A SOLID WALL AND DETACHMENT BY A SHEAR-FLOW .1. PURE SYSTEMS

In water, alcane droplets are deposited by gravity under a smooth glass wall and removed by a shear flow. The setup is described, as well as the cleaning procedure. The increase of the rising velocity of decane droplets was found to be very close to the Hadamard-Rybczynski law. Water films between the droplet and the wall were found to be stable for decane and unstable for pristane; the slow rupture of the film is described in the latter case. The critical shear rate necessary to remove pristane droplets from the wall is measured and found to follow an elementary model.