Experimental and numerical investigations on the effect of a rotating tube in an in-line tube bundle

This study investigates the impact of a rotating tube on the flow characteristics within a tube bank consisting of nine cylinders arranged in an in-line configuration, with a pitch-to-diameter ratio of 1.44, using both experimental and numerical approaches. Experiments are performed in a subsonic wind tunnel to measure pressure distributions at various azimuthal angles along the tubes, using a multi-channel differential pressure system. Drag forces are determined via a wire-strain gauge balance. Numerical simulations are conducted using ANSYS Fluent, employing the URANS-based Shear-Stress Transport (SST) k–[Formula: see text] model, to replicate turbulent cross-flow at two values of Reynolds numbers [Formula: see text] and [Formula: see text]. This study explores the effect of a tube rotation within the array on flow separation angles, pressure distributions and vortex shedding in the wake region, focusing on the effects of different positions of the rotating tube on the flow characteristics of the surrounding tubes. Numerical results closely match the experimental data, demonstrating that the rotational motion significantly mitigates flow separation and reduces drag forces on adjacent tubes. Additionally, the position of the rotating tube within the array plays a critical role in optimizing the fluid forces and pressure distribution, offering enhanced control over the flow within tube banks.