Order in fluids: Shear-induced anisotropy in dense fluids of spherical particles and in gases of rotating molecules

After some general remarks on order in fluids and the anisotropy of distribution functions, results obtained by theoretical considerations and by nonequilibrium molecular dynamics computer simulations are presented for two specific examples. These are the influences of a shear flow, firstly, on the pair correlation function and the static structure factor of a dense fluid of spherical particles and, secondly, on the orientation of the rotational angular momenta of a gas of linear molecules. In the first case, the short and long range partial positional ordering is compared with scattering experimenrs from colloidal solutions. The second example is related to the flow birefringence measurements in gases.