The use of Ctrl+Z in ship design: removing a bulbous bow

Abstract

A bulbous bow is a widely employed feature to enhance the hydrodynamic resistance of ships. More than 95% of the merchant fleet incorporates various types of bulbous bows to reduce wave-making resistance and wave breaking. Bulbous bow is also utilized in smaller vessels like fishing vessels. In certain cases, the initial ship design includes the addition of a bulbous bow by default. In this study, which focuses on a typical Argentinian trawler fishing vessel, we investigate the impact of the bulbous bow on resistance. Taking a reverse approach, we modify the fishing vessel by removing the bulbous bow and we evaluate its hydrodynamics. This research aims to assess the reduction in ship resistance achieved by the bulbous bow under different load conditions and speeds, comparing the vessel with and without the bulbous bow. The numerical analysis uses OpenFOAM, and the results are validated through towing tank experiments. The research demonstrates that the performance of the bulbous bow varies across different conditions, indicating that not always the vessel with a bulbous bow is better.