Rotation of spheroidal tracer particles in spanwise rotating channel turbulence

This Letter focuses on rotational motion of spheroids and is a sequel to our recent investigation on particle orientations in rotating channel flow [Chen et al., “Orientation of inertialess spheroidal particles in turbulent channel flow with spanwise rotation,” J. Fluid Mech. 998, A44 (2024)]. As the channel rotation Ro increases, the mean particle rotation on the suction side decreases monotonically, while on the pressure side, it continuously increases. Increasing and decreasing rates of disks tumbling and rods spinning with increasing Ro were found at the pressure and suction sides, respectively. These findings are likely due to the damping and augmentation of the vorticity fluctuations at the suction and pressure sides caused by the imposed system rotation.