Hydrodynamic characteristics of rigid net panels for mariculture facilities as determined in flume-tank experiment

Abstract

Mariculture facilities composed of rigid nets in practical applications gain increasing popularity due to the benefits of high strength and resistance to biofouling. In terms of structural safety and stability, the hydrodynamic characteristics of rigid nets are essential for design optimization and dynamic simulation, yet a comprehensive understanding is currently lacking. Hydrodynamic experiments were thus conducted to investigate four types of rigid net panels in a flume tank. The experiments considered variations in both the angles of attack (ranging from 0° to 90°) and flow velocities (ranging from 0.3 to 1.2 m/s). The results revealed that the drag coefficient of woven net panels exhibited the largest variation range, ranging from 0.13 to 1.26. The tortoise-shell net panels exhibited the lowest drag coefficients when the net panel was normal to the current while the drag coefficients were largest when the net panel was parallel to the current. The maximum lift coefficients, observed when the value of the angle of attack was 50°, were approximately 0.41 for woven net panels, 0.39 for welded net panels, 0.26 for chain-link net panels, and 0.27 for tortoise-shell net panels. Furthermore, hydrodynamic models of rigid net panels with better prediction performances than previous models were proposed. Considering the diverse application scenarios and hydrodynamic differences, utilizing the specific hydrodynamic models to improve prediction accuracy is recommended.