AUTHOR=Xu Lingyun , Li Peng , Qin Hongde , Xu Zhijing 

TITLE=Numerical studies on wake and turbulence characteristics of aquaculture nets

JOURNAL=Frontiers in Marine Science

VOLUME=Volume 9 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/marine-science/articles/10.3389/fmars.2022.1055873

DOI=10.3389/fmars.2022.1055873

ISSN=2296-7745

ABSTRACT=This paper examines the wake and turbulence characteristics of the equivalent-twine and twisted-twine nets. Unsteady Reynolds-averaged Navier-Stokes (URANS) and the second-moment (Reynolds stress, RSM) simulations are conducted at a Reynolds number, Re=4.5×10^3, based on the effective diameter of the net twine, which corresponds to the subcritical flow regime. The vortex structures and the turbulence statistics are assessed at AOA=90°. The results highlight that the wake interactions for the twisted-twine net are relatively strong compared to the equivalent-twine net, due to the disturbance of the helixes on the twisted twines. In comparison to the classical Karman vortex, the overall vortex shedding of these two nets is well organized. Symmetric vortices form behind the equivalent-twine net, while single vortices form behind the twisted-twine net. The Reynolds normal and shear stresses show symmetric and anti-symmetric profiles. The addition of helixes to smooth circular cylinders changes the flow development, which leads to a decrease of turbulence kinetic energy.