CONDUIT FLOW OF AN INCOMPRESSIBLE, YIELD-STRESS FLUID

The steady flow of an incompressible material of the Bingham viscoplas tic type along a rectangular duct is calculated. This flow has importa nce in a number of geophysical problems. A numerical solution to the p roblem is found using finite differencing of the partial differential equation governing the fluid motion. The flow is seen to consist of a plug in the center of the duct with dead regions of ''no-flow'' at the corners, due to the rectangular cross Section. The variation of this flow pattern as a function of two nondimensional parameters, the yield stress and the aspect ratio, is investigated. (C) 1997 The Society of Rheology.