Dynamics of viscoelastic fluids, melt fracture, and the rheology of fiber spinning

Abstract The hydrodynamic theory for the flow of nonlinear viscoelastic fluids is developed. Two new dimensionless groups must be introduced into the complete second‐order correction of viscoelastic flow. These groups are called the Weissenberg and viscoelastic ratio numbers. Applications to industrially important problems are discussed. It is argued that the Weissenberg number determines the onset of melt fracture.