Effects of Long-chain Molecule Additives in Water on Vortex Streets

Abstract

THE spectacular reductions of turbulent friction which can occur as a result of dissolving certain long-chain molecule substances in water¹ have still not been adequately explained. An explanation might be sought in terms of a continuum theory relating the stresses in the fluid to its motion. Various logically possible sets of such constitutive equations have been proposed, and both the second-order fluid of Coleman and Markovitz² and the anisotropic liquid of Ericksen³ seem attractive as possible models of dilute polymer solutions. It is desirable, therefore, to try to devise simple experiments which will help to decide which model fits the real fluids best and determine the disposable constants in the theoretical model.