Abstract
When transition to turbulence occurs in the Poiseuille flow of water at relatively high rates of shear (greater than 1250 s−1 at the wall) in cylindrical tubes of 2 mm radius, the flow of 0025% (wt/wt) polyacrylamide solutions is destabilized relative to that of the water but when transition to turbulence in water occurs at low rates of shear the flow of the polyacrylamide solution is stabilized.