Доступ предоставлен для: Guest
TSFP DL Home Архив Исполнительный Комитет

SOME DYNAMICAL FEATURES OF THE TURBULENT FLOW OF A VISCOELASTIC FLUID FOR REDUCED DRAG

L. Thais
Unite de Mecanique de Lille, Polytech'Lille, Universite de Lille, Cite Scientifique, Av. Paul Langevin, 59650 Villeneuve d'Ascq, France

Thomas B. Gatski
Institut Pprime, CNRS-Université de Poitiers-ENSMA F86036 Poitiers cedex, France; Center for Coastal Physical Oceanography and Ocean, Earth and Atmospheric Sciences Old Dominion University, Norfolk, Virginia 23529 USA

Gilmar Mompean
Unite de Mecanique de Lille, Polytech'Lille, Universite de Lille, Cite Scientifique, Av. Paul Langevin, 59650 Villeneuve d'Ascq, France

Аннотация

It is well-known that the addition of minute amounts of long polymer chains to organic solvents, or water, can lead to significant turbulent drag reduction (DR). In the present study, direct numerical simulations (DNS) of turbulent channel flow of a viscoelastic fluid, at friction Reynolds numbers ranging from 180 to 1000, are further analyzed. The analysis is focused on the turbulent stress and viscoelastic extra-stress (conformation tensor) fields in order to contrast the dynamics of the viscoelastic and Newtonian fluids and to quantify the effects of enhanced elasticity on the viscoelastic extra-stress fields. The simulation results coupled with the analyzes just mentioned can be useful in further assessing the underlying mechanisms responsible for the occurrence of drag reduction.