Abstract

RAMOS, G.G; SOARES, E.J  and  THOMPSON, R.L. The yield zone concept and its application on a 4:1 abrupt contraction for an apparent-yield-stress fluid. Lat. Am. appl. res. [online]. 2013, vol.43, n.4, pp. 363-367. ISSN 1851-8796.

The yield surface, a concept widely used in the literature that was born together with the Bingham model is discussed from the perspective of other models that are more related to apparent-yield-stress materials. As a consequence, it is necessary to define a yield zone, an intermediate transition region in the flow domain where plasticity manifests itself. A Galerkin Finite Element Method is used to investigate the performance of a SMD viscoplastic material through a 4:1 abrupt contraction. The influence of dimensionless parameters, like the Jump number and an equivalent to the Bingham number, on the size of the yield zone and on the pressure loss of the contraction are investigated

Keywords : Viscoplastic Material; Abrupt Contraction Flow; Finite Element Method; Yield Surface; Yield Zone.