Self-organization and transition to turbulence in isotropic fluid motion driven by negative damping at low wavenumbers 

We observe a symmetry-breaking transition from a turbulent to a self-organized state in direct numerical simulation of the Navier-Stokes equation at very low Reynolds number. In this self-organised state the kinetic energy is contained only in modes at the lowest resolved wavenumber, the skewness vanishes, and visualization of the flows shows a lack of small-scale structure, with the vorticity and velocity vectors becoming aligned (a Beltrami flow).

McComb, W. David; Linkmann, Moritz F.; Berera, Arjun; Yoffe, Samuel R.; Jankauskas, Bernardas. (2015). Self-organization and transition to turbulence in isotropic fluid motion driven by negative damping at low wavenumbers, [dataset]. University of Edinburgh. School of Physics and Astronomy. http://dx.doi.org/10.7488/ds/250.