Laminar and turbulent flow structures in a T-branch

Abstract

Computations for laminar and turbulent flows through a T-branch and an experiment for the turbulent flow are presented in this study. The flow was assumed to be two-dimensional, incompressible, steady and viscous. The laminar flow structure through a T-branch has been investigated for Re=10,100 and 1000 by numerical computations; for each Reynolds number, two different ratios of flow rates between the two branchs were considered. Recirculating flow profiles are presented in details. It was found that separation occurs at the corner of the left side angled wall for Re=100 and 1000. It was noted that a recirculation zone appears at the bottom wall for Re=1000 and flow rate ratio 0.3. The flows at the inlet and outlet of the central branching section were shown to have asymmetric velocity profiles. Turbulent flow through a T-branch has been solved for Re=14455 and flow rate ratio 0.9339 by using a k-ε model developed by D.B.Spalding. Computational result is compared with an experiment performed in this study. Since a hot-film sensor does not have a directional resolution, It was not possible to obtain the recirculating profiles exactly. However, the prediction and the experiment showed a reasonable agreement in qualitative structure. More advanced techniques such as LDV system must be used in the experimental investigation on the recirculating flow region.