[045]  Long-ranged correlations in sheared fluids

J. F. Lutsko and J. W. Dufty, " Long-ranged correlations in sheared fluids", Phys. Rev. E, 66, 41206 (2002) http://jimlutsko.github.io/files/Lutsko_PRE_2002_3.pdf


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-mometum 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 [script l][approximate]sqrt( lambda[sub 0]/a), where lambda0 is the sound damping constant and a is the shear rate.