An Integrated Approach to Modelling Fish Cage Response in the Flow

Abstract

Noticeable progress has been made in recent years regarding sensor-based monitoring and model-based simulation of sea cage response. The discrepancy between measured data and simulation results can cause confusion about the actual deformation of fish cages. This study aims to explore an approach of integrating measured depth data with a deterministic cage model for sea cage response prediction in dynamic analysis software Orcaflex, emphasizing on cage deformation estimation. A Morison-type cage model is divided into several net panels, regulators based on PID theory are developed and incorporated into the cage model to regulate the hydrodynamic properties of cage net panels based on measured depth. Through a case study based on published model tests, it is shown that the model incorporating measured depth can significantly improve the predictions of cage deformation compared with deterministic models. The resultant drag forces from the integrated models are also with reasonably good accuracy.