We present experimental evidence of the striking influence of small additions of high molecular weight polymers on stability and pattern selection in Couette-Taylor flow. Two novel oscillatory flow patterns were observed. One of them is essentially due to the fluid elasticity. The other results from inertial instability modified by the elasticity.

• Received 19 April 1996

DOI:https://doi.org/10.1103/PhysRevLett.77.1480