Christopher W. Macosko, Associate Fellow

Modeling Area Generation in Polymer Binding

Recent experimental work has revealed that viscoelastic drops suspended in another viscoelastic medium tend to flatten considerably when exposed to shear flow. This mode of area generation holds potential as a means for more easily creating polymer barrier materials, among other possible applications. An exploration of this phenomenon, from a fluid dynamics approach by solving the governing transport equations using the Finite Element Method (FEM), was the next step in this group’s research trajectory. The key features and challenges of the problem included the following: full three-dimensionality; two phases, one or both phases being viscoelastic; time-dependent flow; and the drop shape defined by a moving boundary. While FEM is ideally suited to such a problem, difficulties arise in choosing or developing a numerically stable variation of FEM, which allows for large departures from Newtonian fluid behavior. In addition, the three-dimensional aspect of the problem requires special attention to deal with problem size and computation time. The research team has developed code for extending the FEM used previously to study viscoelastic drop formations in symmetric flows to fully three-dimensional flows. They have incorporated adaptive remeshing into the algorithm to allow very large drop deformations to be tracked. Complex phenomena such as many-body effects, e.g. flow-induced collision and coalescence of deformed drops, have been included in the simulations. This research is being extended to include inertial effects, coupled heat and mass transfer, and effects of surfactants on the deformation and coalescence of drops.

Research Group and Collaborator

Tony Anderson, Supercomputing Institute Undergraduate Intern
Vittorio Cristini, Supercomputing Institute Research Scholar
Jeffrey J. Derby, Faculty Collaborator
Russell Hooper, Graduate Student Researcher
Pieter Spitael, Graduate Student Researcher
Matthijs Toose, Research Associate
Xiao Dong Zhang, Graduate Student Researcher
Rui Zhao, Graduate Student Researcher