Steady Flow of Purely Viscous Shear-Thinning Fluids in a 1:3 Planar Gradual Expansion

Abstract

Laminar flow of non-Newtonian fluid (shear-thinning) through a 1:3 planar gradual expansion is numerically investigated, for various Power-Law index (0.6, 0.8 and 1.0) and expansion angles (15, 30, 45, 60 and 90°) at different generalized Reynolds number (1 ≤ Reg ≤ 400). The study of these parameters effect on the flow pattern allowed the determination of the two critical generalized Reynolds numbers (Regcr1 and Regcr2), which correspond to the transition from the symmetric to the asymmetric flow and the appearance of the third recirculation zone respectively. The results showed that decreasing the Power-Law index or the expansion angle stabilizes the flow by increasing significantly the two critical generalized Reynolds numbers. In order to predict the two critical generalized Reynolds numbers, two correlations have been proposed.

Hydrothermal analysis of water-Al2O3 nanofluid flow through a sudden expansion channel with intermediate step

“…Flow through a sudden expansion channel is a well-known phenomenon [Mostafavi et al (2017)]. Many authors [Mostafavi et al (2017); Menouer et al (2019)], experimentally and numerically, have shown that the increase in Re causes the existence of two or more flow separation zones at the lower and upper corner walls, which causes a substantial heat loss [Galuppo et al (2017)]. Hilo et al (2020) studied different properties of the hydrothermal phenomena of flow over a suddenly expanded channel.…”