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Department of Chemical Engineering
University of Delaware
Abstract-
The recent progress in understanding the mechanism of polymer-induced drag
reduction in turbulent viscoelastic flows through large scale spectral
simulations is going to be presented. High performance computations have
helped us generate reliable data for the
average and various turbulence statistics for the turbulent channel flow of
a dilute viscoleastic polymer solution modeled from first
principles with the FENE-P differential constitutive equation.
In particular, our most recent data have helped us elucidate the dependence
of drag reduction on the Weissenberg number: Drag
reduction sets in at a critical value of the Weissenber number (about 8 for
the FENE-P model used here) and continues increasing,
albeit at a lower rate, even at the highest value examined (125)
asymptotically approaching a value close to the Virk maximum limit.
In addition, the effect of an increasing Reynolds number is examined and
found to be independent of that of the flow elasticity, the
drag reduction remaining practically unchanged as the friction Reynolds
number increases from 125 to 590.
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