Dynamic wetting and stress singularity on contact line

A theoretical investigation is conducted to understand the contact linemovement and associated contact angle phenomena. Contact line is supposed to move on a thinprecursor film, and contact line has a velocity and is subject to viscous stress on the film orgeometrically on the solid surface. With the introduction of a characteristic parameter, λ', themovement of contact line and contact angle phenomena are very well described in both physics andmathematics. The viscous shearing stress exerted by liquid on solid surface was derived, and thebehavior of dynamic contact angle was recognized on rough solid surfaces. The analyses indicate thatcharacteristic parameter λ' is dependent upon solid wall intrinsic property and mechanicalperformance, and is irrelevant to liquid property. Theoretical predictions are in good agreementwith available experimental data in literature.