Entrance region flow of Bingham fluid in an annular cylinder

The entrance region flow of a Bingham fluid in an annular cylinder has been investigated numerically without making prior assumptions on the form of velocity profile within the boundary layer region, which is determined by a cross sectional integration of the momentum differential equation for a given distance from the channel entrance. Using the macroscopic mass and momentum balance equations, the thickness of the core, the entrance length, velocity profile and the pressure drop have been obtained at each cross section of entrance region of an annuli for different values of Bingham number and for various values of aspect ratio.