Turbulent transport in annular Poiseuille flow with axial rotation

Annular Poiseuille flow, which is the axial Poiseuille flow between two concentric circular cylinders, is an important canonical system for the study of wall turbulence. In the present work, the variation of momentum and heat transport in the turbulent annular Poiseuille flow under the influence of axial system rotation is investigated. We performed direct numerical simulation under radius ratio η=0.5, friction Reynolds number Reτ=200, and Prandtl number Pr=1. The intensity of rotation effect is characterized by the rotation number, which varies from 0 to 128 in the present work. Our results show a counter-intuitive phenomenon: when the rotation increases from zero, the heat transfer exhibits a monotonic increase, while the axial flow rate has a monotonic decrease, which are both opposite to the trends in a rotating pipe flow. We also reveal the main effect of the Coriolis force on the mean velocity profiles and flow structures. A more thorough investigation is conducted by studying the budget terms of Reynolds stresses and turbulent heat flux, which explores the enhancement effect of the Coriolis force on the turbulent radial transport of axial momentum and heat, along with its redistribution mechanism on turbulent kinetic energy. Finally, energy spectra demonstrate the emergence of large-scale structures in the radial-azimuthal plane under strong rotation.