Stability Analysis of a Dense Hard-Sphere Fluid Subjected to Large Shear—Shear-Induced Ordering

The stability at finite wave numbers of a hard-sphere fluid subjected to a large shear is examined by use of hard-sphere kinetic theory. For a fixed density, for molecular-scale wave numbers, and for a critical shear rate the fluid is found to become unstable with respect to density waves in the direction of the velocity gradient. The critical shear rates obtained are close to those found by Erpenbeck in his nonequilibrium molecular-dynamics simulations of shear-induced ordering.