Rotating Cylinder as a Flow Split Controller in a Rectangular T-channel: Power-Law Fluids

The present work endeavours to understand numerically the flow characteristics of power-law fluids in a rectangular T-channel over a wide range of conditions: power-law index (0.2 ≤ n ≤ 1), the rotational velocity of the cylinder (-5 ≤ α ≤ 5) at Re = 45. A rotating cylinder (both in the clockwise (α > 0) and anticlockwise (α < 0)) placed at the T-junctions is used here as a flow rate controlling strategy from the channel outlets. The flow is assumed to be steady, laminar and incompressible. The detailed flow kinematics has been visualized in terms of streamline patterns, flow-split ratio (i.e., the ratio of the main branch flow rate to the side branch flow rate), hydrodynamic forces (total and its pressure component) over the cylinder surface and torque (due to the force required to maintain the cylinder rotation in the free stream of power-law fluid). The flow split ratio is seen to be significantly affected by the cylinder rotation while the stationary cylinder is found to divide the flow equally in both main and side branches. The total hydrodynamic force and its pressure coefficient are seen to be a strong function of cylinder rotation as well as the power-law index. The magnitude of the torque is seen to be independent of the direction of cylinder rotation.