Wetting Flows

The debonding of adhesives filling the gap between flat surfaces is a commonly encountered process in food industry, characterization, fabrication and application of pressure sensitive adhesives and even in biological flows. We have developed a 3D grid generation method (see figure below) in order to account for the spatial and temporal dependence of the non-linear physics at the contact line. The evolving cavity penetrates the surrounding viscous medium by the translation of the moving contact line and may form fingers (the so-called viscous fingering instability). Depending on the balance between the normal and tangential forces, locally at the surroundings of the contact line, the fingers can grow or retract leading to dendritic structures that affect severely the adhesive strength of the material.

wetting

Contours of the velocity magnitude on the surface of an evolving air enclosure and on the solid substrate, via a slip condition.

wetting1

Contours of the magnitude of the rate of strain tensor on the same surfaces.