Numerical Study of Laminar Bingham Fluid in Axisymmetric Sudden Expansion

A numerical study was carried out to investigate the laminar flow of Bingham fluid through an axisymmetric sudden expansion of four aspect ratios and various values of Reynolds number between [50~200] and Bingham number [0~2]. By using the commercial code Ansys-Fluent, this paper focuses on presenting Bingham's flow through an axisymmetric sudden expansion to determine the length and intensity of recirculation zones and shed light on the local loss coefficient. The results show an increase in the reattachment length and the eddy intensity of the recirculation zones by increasing the Reynolds number and the aspect ratio and decreasing with increasing the Bingham number and vice versa, the local loss coefficient increases as the aspect ratio increases for the Newtonian fluid this effect is reflected in the Bingham fluid, the increase of the Bingham number also increases the local loss coefficient, dimensionless equations has built to predict all the reattachment lengths, the eddy intensity and the local loss coefficient.