A Numerical Simulation for the Determination of the Shunt Ratio at a T-Junction With Different Branch Angles, Viscosities, and Flow Rates

Abstract

T-junctions have been applied in water-control structures. A comprehensive understanding of shunt characteristics can contribute to the optimal design of T-junctions. In this work, we seek to understand the shunt ratio of fluids with different viscosities in a T-junction and to achieve a greater shunt ratio. The computational fluid dynamics (CFD) approach is applied to study the influence of the properties, such as the fluid viscosity, the branch angle, the channel shape, and the flow rate, on the shunt ratio in a T-junction. The viscosity of oil can be divided into three intervals, and the optimal angles of the T-junction are different in each interval. For the fluid viscosity in the 1–20 cP range, the optimal branch angle is in the 45–60 deg range. For the fluid viscosity in the 20–65 cP range, the branch angle should be designed to be 45 deg. For the viscosity greater than 65 cP, the branch angle should be designed to be 75 deg. The appearance of the eddy and secondary flow will reduce the flow. The secondary flow and eddy intensity on the branch increase with increasing angle. The secondary flow intensity of the main channel decreases gradually with the increase in the angle. This study provides an important guidance for the design of automatic water control valve tools.