Abstract
Experimental and theoretical studies of early turbulence in pipe flows of drag-reducing polymer solutions are described in this work. The experiments show that a critical onset wall shear stress, which increases with solvent viscosity, is associated with the phenomenon. The relationship of the onset condition to polymer concentration is a strong function of viscosity over the range of variables considered. Atheoretical, hydrodynamic stability analysis of the laminar pipe flow of a convected Maxwell fluid is presented. The results suggest that early turbulence is a hydrodynamic instability phenomenon.
