RIS ID
24481
Abstract
This paper investigates turbulent flows with or without polymer additives in open channels and pipes. Equations of mean velocity, root mean square of velocity fluctuations, and energy spectrum are derived, in which the shear stress deficit model is used and the non-Newtonian properties are represented by the viscoelasticity α*. The obtained results show that, with α* increment, (1) the streamwise velocity fluctuations is increased, (2) the wall-normal velocity fluctuation is attenuated, (3) the Reynolds stress is reduced, and (4) there is a redistribution of energy from high frequencies to the low frequencies for the streamwise component, but dimensionless distribution over all frequencies almost remains the same as that in Newtonian fluid flows. Good agreement between the derived equations and experimental data in small drag-reduction regime is achieved, which indicates that the present model is workable for Newtonian/non-Newtonian fluid turbulent flows.
Publication Details
Yang, S. & Dou, G. (2008). Modeling of viscoelastic turbulent flow in channel and pipe. Physics of Fluids, 20 (6), 065105-1-065105-13.