Experimental investigation of viscoelastic flow past a cylinder is conducted for a polyisobutylene-based polymer solution. High-image-density particle image velocimetry is utilized to quantitatively determine the spatial features of elastic wake instabilities. The viscoelastic flow bifurcates from steady two-dimensional flow to steady three-dimensional flow for values of the Deborah number (dimensionless flow rate) greater than a critical value. These hydroelastic flow transitions are manifested in the form of three-dimensional cells spaced periodically along the axis of the cylinder. The elastic flow structures do not exist in the Newtonian counterpart of creeping flow past a cylinder.
Experiments in Fluids
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