Elongational flow behavior of viscoelastic liquids: Part I. Modeling of bubble collapse

A spherically collapsing gas bubble will create a uniaxial extension of the fluid surrounding it. This flow may be readily analyzed, and it is possible to relate observed experimental parameters such as the pressure inside the bubble and the bubble collapse rate to the predictions of viscoelastic constitutive relations. This study compares the predictions of the Newtonian fluid and a viscoelastic model to observed bubble collapse in three fluids: one Newtonian fluid and two viscoelastic polymer solutions. Good agreement between data and the model was observed for the Newtonian experiments. The viscoelastic solutions, however, yielded rates of collapse which were greater than the Newtonian predictions based on equal zero‐shear viscosity. Subsequent modeling with a modified corotational Maxwell fluid yielded good agreement with the data for the transient elongational response in the viscoelastic solutions.