PARTICLE-PHASE PRESSURE IN A SLOW SHEARING FLOW BASED ON THE NUMERICAL-SIMULATION OF A PLANAR SUSPENSION OF ROUGH CONTACTING CYLINDERS

Planar Stokes flow of a concentrated planar suspension of rigid cylind ers is simulated using the finite-element method. A constraint conditi on, limiting cylinder approach to a specified distance, is applied to simulate interparticle contacts. The results of these simulations reve al a stress response and ordering of the cylinders which is similar to experimental observations of suspensions of nominally spherical parti cles. These results include direct observations of anisotropic structu re, as well as the development of a distinct particle-phase pressure r esulting from the asymmetry of interparticle contacts and the conseque nt developed anisotropy. A simple pair-wise interaction model is propo sed for nb initio prediction of the particle-phase pressure for these planar suspensions of cylinders. (C) 1998 The Society of Rheology.