NUMERICAL STUDY OF NON-NEWTONIAN FLUID FLOWS IN YSHAPED STRUCTURES

Abstract

Vascular and respiratory trees are complex flow systems consisting of series of large and small ducts. Although the literature reports several cases that are in accordance with Hess-Murray law, there are also some branching patterns of natural systems that deviate from this law. In this study, a numerical analysis was carried out to investigate laminar fluid flow of non- Newtonian fluids, in Y-shaped flow structures with different ratios between the sizes of parent and daughter ducts. The non-Newtonian behavior was modeled using the power-law equation. The main parameters in the present study were the angle between the daughter ducts and the relationships between the diameters and between the lengths of the parent and daughter ducts. The performance of the branching systems was evaluated in terms of total hydraulic resistance and distribution of shear stresses. The effect of rheological parameters was also analyzed. These results were compared with analytical results obtained based on the Constructal Law.