On the search for numerical boundary conditions for the computation of dynamic contact lines

MARIA DELIA GIAVEDONI; DIEGO M. CAMPANA; FERNANDO A. SAITA; RAMÓN CERRO

Saint Paul, Minnessota

Simposio; 15th International Coating Science and Technology Symposium (ISCST); 2010

Theoretical understanding of the combined effect of different forces on the movement of dynamic contac lines is one of the outstanding problems in fluid mechanics. Much research has been done to understand this problem since the pioner work of Huh and Scriven (JCIS, 1971). Although flawless from a mathematical point of view, Huh and Scriven solution configures a modern fluid dynamics paradox (Fuentes and Cerro, 2005). Unlike most physical phenomena where small causes result in small effects and large causes result in large effects, static and dynamic contact lines are macroscopic phenomena but depend (for small Capillary numbers) strongly on short and long-range molecular forces, of sub-micrometer range. Molecular, electrostatic and structural forces near a triple, fluid-liquid-solid contact line are responsible for static configurations and static contact angles and also for macroscopic flow patterns in the vicinity of dynamic contact lines at small Capillary numbers.