Elastic instabilities of polymer solutions in cross-channel flow.
When polymer molecules pass near the hyperbolic point of a microchannel cross flow, they are strongly stretched. As the strain rate is varied at low Reynolds number (< 10(-2)), tracer and particle-tracking experiments show that molecular stretching produces two flow instabilities: one in which the velocity field becomes strongly asymmetric, and a second in which it fluctuates nonperiodically in time. The flow is strongly perturbed even far from the region of instability, and this phenomenon can be used to produce mixing.
Arratia
P E
PE
Physics Department, Haverford College, Haverford, PA 19041, USA.
Thomas
C C
CC
Diorio
J
J
Gollub
J P
JP