inertia effects on the flow of viscoplastic fluids through an abrupt contraction

This paper is concerned primarily with the effects of inertia (reynolds number) on the laminar flow of a non-newtonian viscoplastic fluid through a sudden contraction in the planar and axisymmetric geometries# the influence of reynolds number on the structure of the flow and pressure losses is studied using a numerical approach# the radius of the rigid moving zone is always unchanged for the different re, but the downstream rigid moving zone is pushed away and it will vanish at re=303# inertia and yield stress act in opposite ways# when re increases, pressure loss due to the singularity decreases# on the contrary, as bingham number increases, the pressure loss increases significantly# moreover, a comparison between pressure drops in sudden expansion and abrupt contraction has been performed# the pressure loss due to the sudden expansion is higher than contraction (55%) until bi= 100, in which they reach the same value of 2#8# finally, the provided numerical results are validated by available experimental data#