Wavenumber dependence of very large-scale motions in ciclope at 4800 ≤ Reτ ≤ 37,000

Abstract

The present work aims at investigating the very large-scale structures of turbulent pipe flow in CICLoPE at high Reynolds numbers. According to recent studies, some open questions remain to be answered to identify accurate sizes of these turbulent structures in pipe flow. The CICLoPE facility has been therefore utilized, providing an opportunity to approach high Reynolds number flows with high enough resolution in terms of the viscous length scale, allowing us to investigate the behavior of such turbulent structures. Meandering structures, usually referred as VLSM (very large-scale motions), have been identified with claimed extension up to 20R, where R is the pipe radius.