Hydrodynamic characteristics and internal flow field of a perforated fishing vessel under wave conditions

Abstract

This research focuses on an innovative design of a perforated fishing vessel, aiming to precisely and efficiently evaluate its hydrodynamic performance and the characteristics of its internal flow fields. Initially, the boundary element method is employed to tackle the challenge of hydrodynamic responses in structures with arbitrary openings, quantifying added mass, damping effects, and dynamic responses under various filling scenarios. This sets a foundation for assessing structural stability. Subsequently, using the CFD method, based on the Navier–Stokes equations, a deep exploration into the mechanisms of how fluid viscosity and nonlinear effects influence the flow fields inside and outside the culture compartments is conducted. This reveals the impact of detailed flow field features on the fish welfare of fishing vessel design. The CFD method implemented the forced motion of the aquaculture fishing vessel based on FLUENT UDF, with the specific parameters of the moving boundary conditions determined by the results of the BEM method. The frequency-domain results show that the heave motion response is significantly greater than the sway. Compared with the isolated heave flow field results, the coupling heave-roll motion causes obvious vortex phenomena in the fluid on both sides of the perforated fishing vessel.