Viscoelastic Flows in Abrupt Contraction-Expansions I. Fluid Rheology

I. Fluid Rheology In this note (I of IV) we summarize the rheological properties of the test fluid in shear and extension. The viscoelastic fluid consists of an 0.025 wt% solution of monodisperse polystyrene (PS) (Scientific Polymer Products, Inc.) with a polydispersity of 1.03. The polystyrene is dissolved in oligomeric styrene (Hercules Piccolastic A5) to yield a dilute solution with c/c* = 0.24. A careful GPC characterization was performed after the solution had been thoroughly mixed. The average molecular weight was determined to be 2.03×10 g/mol, slightly smaller than the manufacturer’s reported value of 2.25×10 g/mol. The resulting solution falls into the class of Boger fluids which are highly elastic with an almost constant viscosity [1]. Table 1 lists all the relevant viscometric properties of the PS solution.