title: Dynamic wetting of viscoelastic droplets.
abstract: We conduct numerical experiments on spreading of viscoelastic droplets on a flat surface. Our work considers a Giesekus fluid characterized by a shear-thinning viscosity and an Oldroyd-B fluid, which is close to a Boger fluid with constant viscosity. Our results qualitatively agree with experimental observations in that both shear thinning and elasticity enhances contact line motion, and that the contact line motion of the Boger fluid obeys the Tanner-Voinov-Hoffman relation. Excluding inertia, the spreading speed shows strong dependence on rheological properties, such as the viscosity ratio between the solvent and the polymer suspension, and the polymeric relaxation time. We also discuss how elasticity can affect contact line motion. The molecular migration theory proposed in the literature is not able to explain the agreement between our simulations and experimental results.
authors.affiliation: Linné FLOW Center, Department of Mechanics, The Royal Institute of Technology, 100 44 Stockholm, Sweden and School of Energy and Power Engineering, Jiangsu University, 212013 Zhenjiang, China.
authors.forename: Yuli
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Linné FLOW Center, Department of Mechanics, The Royal Institute of Technology, 100 44 Stockholm, Sweden.
authors.forename: Do-Quang
authors.initials: DQ
authors.lastname: Minh
authors.affiliation: Linné FLOW Center, Department of Mechanics, The Royal Institute of Technology, 100 44 Stockholm, Sweden.
authors.forename: Gustav
authors.initials: G
authors.lastname: Amberg