(237i) Active and Hibernating Turbulence in Minimal Channel Flow of Newtonian and Polymeric Fluids
AIChE Annual Meeting
2010 Annual Meeting
Engineering Sciences and Fundamentals
Non-Newtonian Flows and Nonlinear Hydrodynamics
Tuesday, November 9, 2010 - 10:30am to 10:45am
Turbulent channel flow of drag-reducing polymer solutions is simulated in minimal flow geometries. Even in the Newtonian limit, we find intervals of ?hibernating? turbulence that display many features of the universal maximum drag reduction (MDR) asymptote observed in polymer solutions: weak streamwise vortices, nearly nonexistent streamwise variations and a mean velocity gradient that quantitatively matches experiments. As viscoelasticity increases, the frequency of these intervals also increases, while the intervals themselves are unchanged, leading to flows that increasingly resemble MDR.