The flow through an orifice of semi-rigid-polymer solutions

The orifice flow of scleroglucan solutions is studied. Under given conditions, this molecule behaves as a semi-rigid rod in solutions. Solutions in glucose-water syrups were examined, which show considerable vortex growth in orifice flow depending on flow regime and concentration. The vortex reattachment length is studied as a function of regime and concentration. The flow curves in orifice flow are characterized by a linear pressure drop - flow rate relation. The extensional viscosity is derived from the orifice flow data by the Binding analysis. Comparison with the Batchelor analysis for closely spaced fibers is satisfactory if molecular extension as well as alignment along the streamlines is considered.