Effect of Contraction Width on the Vortex Formation of Viscoelastic Flow in Asymmetric Planar Contractions

Abstract

In this paper, the flow behavior of viscoelastic fluid in asymmetric planar contraction geometry is studied by flow visualization and PIV measurement. An attention is placed on the influence of the contraction widths of the geometry, which is evaluated by the PIV measurement of velocity fields in three channels with different contraction widths H 0 = 408, 566, 728 μm. Experimental results show that the entry flow can be categorized into Newtonian-like flow, transitional flow and vortex formation flow. It is found that the critical Wi number, over which the vortex formation occurs in the channel, is reduced with increasing the channel width.