Long-ranged correlations in sheared fluids.
The presence of long-ranged correlations in a fluid undergoing uniform shear flow is investigated. An exact relation between the density autocorrelation function and the density-momentum correlation function implies that the former must decay more rapidly than 1/r, in contrast to predictions of simple mode-coupling theory. Analytic and numerical evaluation of a nonperturbative mode-coupling model confirms a crossover from 1/r behavior at "small" r to a stronger asymptotic power-law decay. The characteristic length scale is l approximately sqrt[lambda(0)/a], where lambda(0) is the sound damping constant and a is the shear rate.
Lutsko
James F
JF
Center for Nonlinear Phenomena and Complex Systems, Université Libre de Bruxelles, Campus Plaine, CP 231, 1050 Brussels, Belgium.
Dufty
James W
JW