Distinct organizational states of fully developed turbulent pipe flow

Abstract

Organizational states of turbulence are identified through novel analysis of large scale pipe flow experiments at a Reynolds number of 35000. The distinct states are revealed by an azimuthal decomposition of the two-point spatial correlation of the streamwise velocity fluctuation. States with dominant azimuthal wave numbers corresponding to kθ=2,3,4,5,6 are discovered and their structure revealed as a series of alternately rotating quasistreamwise vortices. Such organizational states are highly reminiscent of the nonlinear traveling wave solutions previously identified at Reynolds numbers an order of magnitude lower.