Optimization of three-catamaran formation for resistance performance under different Froude numbers and configurations

Abstract

This study explores optimizing drag reduction in three-catamaran formations under different Froude numbers and configurations. Initially, the numerical methods and models employed in this study are introduced, followed by a grid convergence analysis to ensure the accuracy and reliability of the numerical simulations. The still water resistance of the Delft-372 catamaran is numerically calculated at different Froude numbers (Fr) and compared with experimental data, showing a strong correlation and validating the numerical approach. Subsequently, the flow field and wave height along the hull centerline of the catamaran are analyzed at Fr = 0.3, 0.4, 0.5, and 0.6. Focusing on three-catamaran formations, this study separately investigates the drag characteristics of tandem, parallel, and triangle configurations to reveal the influence mechanisms of different configurations. The computational results indicate that certain formation configurations and distances can reduce resistance for both the entire formation and individual catamarans at different speeds. Additionally, the lateral force, bottom pressure, and bow-stern wave heights experienced by catamarans in formation were analyzed to provide a comprehensive understanding of their hydrodynamic interactions. From the perspectives of drag reduction and safety, the tandem formation is most advantageous, followed by the triangle formation, with optimal spacing recommended for different speeds. To mitigate the adverse effects of lateral force, the spacing between catamarans in parallel formation should exceed 1 B.