Bubble Deformation and Growth Inside Viscoelastic Filaments Undergoing Very Large Extensions

Abstract

Motivated by the probe experiment for characterizing the adhesion strength of polymeric materials, we studied the axisymmetric extensional flow of a viscoelastic liquid filament that contains one or three initially spherical bubbles along its axis of symmetry. The filament is confined between two parallel and coaxial disks of the same radius and its initially cylindrical outer surface is surrounded by air. The flow is induced by the axial extension of the upper disk under constant velocity, while the lower disk remains stationary. The rheology of the liquid is described by the exponential Phan–Thien and Tanner viscoelastic model. A quasi-elliptic transformation combined with domain decomposition and local mesh refinement is employed to discretize the domain. The mixed finite element Galerkin method for the mass and momentum balances combined with the EVSS-G method and SUPG weighting for the constitutive equation are used to obtain their weak forms. All these are necessary for the successful simulation of ...