Comparison of small shear flow rate–small wave vector static structure factor data with theory.

Light scattering measurements determined the ratio of the nonequilibrium to equilibrium static structure factor for suspensions of ‘‘hard spheres’’ undergoing shear flow as a function of volume fraction of the suspended particles, the shear rate, and a limited number of scattering angles. These data are compared with existing theoretical predictions for the static structure factor ratio in the limit of small shear flow rates. We conclude that the existing theories, some which are considered exact at low volume fractions, give increasingly poor estimates of the true structure factor at small scattering angles as the volume fraction increases. [ABSTRACT FROM AUTHOR]