On a nonhomogeneous Bingham fluid (Q1074394)

(From author's summary) The nonstationary motion of a Bingham fluid, which is a special type of non-Newtonian material, is considered. In this paper we are concerned with the initial-boundary value problem for bounded domains and nonconstant densities. This leads to a variational inequality coupled with the continuity equation for conservation of mass, for which the existence of appropriately generalized solutions is proved. The problem of uniqueness and regularity of the solutions for the general problem remains open.