unsteady flows of inhomogeneous incompressible fluids

in this paper, we study the unsteady motion of inhomogeneous incompressible viscous fluids. we present the results corresponding to stokes' second problem and for the flow between two parallel plates where one is oscillating. one of the main areas of interest in fossil energy related applications, such as power plants, atomization, biomass, alter- native fuels, etc., is the use of slurries, specifically coal–water or coal–oil slurries, as the primary fuel. some studies indicate that the viscosity of coal–water mixtures depends not only on the volume fraction of solids, the mean size, and the size distribution of the coal, but also on the shear rate, since the slurry behaves as a non- newtonian fluid (see massoudi and phuoc). at the same time, there are studies which indicate that preheating the fuel results in better performance (see gupta and massoudi) and as a result of such heating, the viscosity changes.