Biomedical subjects

Christophe Clanet

Publications and source records attributed to Christophe Clanet.

4 recordsLinked to original sources

PubMed2004

Capturing drops with a thin fiber.

We study experimentally the dynamics of drops impacting horizontal fibers and characterize the ability of these objects to capture the drops. We first show that a drop larger than a critical radius cannot be trapped by a fiber whatever its velocity. We determine this critical size as a function of the fiber radius. Then we show that for smaller drops, different situations can occur: at a low impact velocity, the drop is entirely captured by the fiber, whereas some liquid is ejected when arriving faster. We quantify the threshold velocity of capture.

Journal Article↗

PubMed2004

First steps in the spreading of a liquid droplet.

We describe the first steps of spreading of a liquid droplet brought in contact with a solid that it wets completely. Usually, it is assumed that the dynamics of the droplet results from a balance between the spreading forces and viscosity. But before this classical stage, inertia resists to the motion, which leads to a very different dynamic law. We study experimentally the nature of this law, compare our results with recent theoretical predictions, and determine the duration of this inertial regime.

Journal Article↗

PubMed2004

Secrets of successful stone-skipping.

Skipping stones across water has been a popular pastime for thousands of years - the rules of the game have remained unchanged since the time of the ancient Greeks - and the world record, set by J. Coleman-McGhee in 1992, is believed to be 38 rebounds. Following earlier attempts to analyse the physics of this ancestral human activity, we focus here on the crucial moment in stone skipping: when the stone bounces on the water's surface. By monitoring the collision of a spinning disc with water, we have discovered that an angle of about 20 degrees between the stone and the water's surface is optimal with respect to the throwing conditions and yields the maximum possible number of bounces.

Humans↗

PubMed2002

Contact time of a bouncing drop.

When a liquid drop lands on a solid surface without wetting it, it bounces with remarkable elasticity. Here we measure how long the drop remains in contact with the solid during the shock, a problem that was considered by Hertz for a bouncing ball. Our findings could help to quantify the efficiency of water-repellent surfaces (super-hydrophobic solids) and to improve water-cooling of hot solids, which is limited by the rebounding of drops as well as by temperature effects.

Journal Article↗