Flow near an oscillating cylinder in dilute viscoelastic fluid

THERE are many natural phenomena in which nonlinear interactions of time-dependent inputs give rise to steady—that is, time-independent outputs. One of these is a steady streaming belonging to a class of secondary flows sometimes called acoustic streaming. It occurs when a circular cylinder oscillates normal to its axis in an unbounded Newtonian fluid1–3. We report here on the steady secondary flow induced when a long thin cylinder oscillates as described in a viscoelastic liquid. We found that the direction of steady streaming is opposite to that found for the bulk of fluid when the experiment is performed with a Newtonian fluid.