An explanation of the drag reduction via polymer solute

The remarkable phenomenon of the drag reduction via addition of small amounts of polymer molecules to a Newtonian solvent was observed experimentally long ago. However, the theoretical explanations of this observation are not overwhelming yet. In this note, we present a possible theoretical account of the phenomenon. It is based on the use of the Navier-Stokes model with viscous strength for the solvent and the upper-convected Maxwell model for the polymer solute. Simple analytical calculation shows that the laminar flow of the solvent is stabilized by an addition of the polymer solute and, thus, the transition to the chaotic and slower on average turbulent motion is suppressed.