SHAPE OF A SLIDING CAPILLARY CONTACT DUE TO THE HYSTERESIS OF CONTACT ANGLE: THEORY AND EXPERIMENT

We consider a classical problem of a capillary neck between a parabolic body and a plane with a small amount of liquid in between. In the state of thermodynamic equilibrium, the contact area between the bodies and the liquid layer has a circular shape. However, if the bodies are forced to slowly move in the tangential direction, the shape will change due to the hysteresis of the contact angle. We discuss the form of the contact area under two limiting assumptions about the friction law in the boundary line. We also present a detailed experimental study of the shape of sliding capillary contact in dependence on the roughness of the contacting surfaces.

Automated summary

The classical problem of a capillary neck between a parabolic body and a plane with a small amount of liquid is discussed. The circular shape of the contact area in the state of thermodynamic equilibrium changes due to hysteresis when the bodies are forced to move tangentially. Experimental study shows the shape of sliding capillary contact depends on the roughness of the contacting surfaces.