EXTENSIONAL FLOW THROUGH MICROFABRICATED HYPERBOLIC CONTRACTIONS

Abstract. Experiments and numerical simulations are used to investigate the extensional flow through a 3-D planar hyperbolic micro-contraction. A converging geometry with a Hencky strain of two was designed to produce a constant extensional rate along the centerline. This configuration was used for the examination of Newtonian flows at low to moderate Reynolds numbers and viscoelastic flows at low Deborah numbers. Numerical simulations of the flow in the micro-contractions were obtained from a finite-volume method using non-orthogonal block-structured collocated meshes. The numerical results are compared to experimental measurements. For the base case of Newtonian flow, the numerical predictions show good agreement with experiments. We also report preliminary results for a semi-dilute solution of polyethylene oxide.