DNS study of turbulent flow in a spanwise rotating square duct at high rotation numbers

摘要

In this paper, direct numerical simulations (DNS) have been performed to study the effects of Coriolis forces on the turbulent field confined within a square duct subjected to spanwise system rotations at very high rotation numbers. The first- and second-order flow statistics, two-point correlations and spectra of velocity fluctuations are analyzed. In comparison with the non-rotating case, secondary flows are induced by system rotations and appear as streamwise counter-rotating vortices. It is observed that at sufficiently high rotation numbers, a Taylor-Proudman region (mean streamwise velocity does not vary along the axis of rotation) appears and complete laminarization is almost reached near the top and side walls. The impact of large organized secondary flows on the production rate and re-distribution of turbulent kinetic energy has been investigated through a spectral analysis.