Abstract. We investigate velocity probability distribution functions (PDF) of sheared hard-sphere suspensions. As observed in our Stokes flow simulations and explained by our single-particle theory, these PDFs can show pronounced deviations from a Maxwell-Boltzmann distribution. The PDFs are symmetric around zero velocity and show a Gaussian core and exponential tails over more than six orders of magnitude of probability. Following the excellent agreement of our theory and simulation data, we demonstrate that the distribution functions scale with the shear rate, the particle volume concentration, as well as the fluid viscosity.

PACS numbers: 02.50.Ey, 47.55.Kf, 77.84.Nh

Print publication: Issue 3 (August 2008)
Received 16 May 2008, accepted for publication 16 June 2008
Published 27 June 2008