Effect of a Towed Trawl on the Hydrodynamic Forces of Acting on the Fishing Vessel

Fishing vessels experience significant hydrodynamic changes when towing a trawl, affecting their stability, maneuverability, and fuel efficiency. Understanding these effects is crucial for optimizing vessel performance and ensuring safe and efficient fishing operations. This study investigates the influence of a towed trawl on the hydrodynamic forces acting on a fishing vessel. The interaction between the vessel and the trawl introduces additional resistance, affects maneuverability, and alters the overall dynamic behavior of the system. To analyze these effects, a model test was conducted to predict the hydrodynamic forces acting on the fishing vessel by towing a trawl behind the model ship. The Antarctic krill trawl was selected as the target trawl in this study. A series of captive model tests such as static drift test, circular motion test with drift and dynamic test were performed with and without a towed trawl to obtain the hydrodynamic forces. The influence of drift angle, yaw rate and acceleration is also considered. The towed trawl significantly affects the ship's hydrodynamic forces, particularly in the large drift angle and large yaw rate. It created an additional drag in water and it made the ship's hydrodynamic forces increase. The hydrodynamic coefficients were calculated due to the influence of the towed trawl. The results provide insights into optimizing fishing operations by improving vessel performance and efficiency under trawling conditions through changes in hydrodynamic forces due to the towed trawl.