Hydrodynamic characteristics of plane netting used for aquaculture net cages in uniform current

摘要

The hydrodynamic characteristics of polyethylene (PE) netting and chain link wire netting with different types of twine diameter and mesh size for aquaculture net cages were examined by experiments in a flume tank. The drag coefficient C-D0 of plane netting set parallel to the water flow increases in the order of PE netting with diamond mesh, PE netting with square mesh and chain link wire netting. The drag coefficient C-D90 of the chain link wire netting set normal to the water flow was 0.8-0.9 times that of the PE netting. Moreover, the drag coefficient C-D theta and lift coefficient C-L theta of PE netting and chain link wire netting set at various angles of attack to the water flow were estimated by empirical equations as functions of C-D0, C-D90, mesh factor and angle of attack, which provide a relevant basis for analyzing and predicting the behavior characteristics of cages in the sea.