The Effect of Various Bulbous Bow Forms on The Resistance of a Black Sea Type Fishing Boat

In this study, resistance analyses of a 35-meter-long Black Sea Type Fishing Boat with various bow forms were conducted using Computational Fluid Dynamics (CFD). The boat's bow shapes included a normal bow without a bulb, a special bulb, a special-elliptical bulb, and an elliptical bulb. To determine the resistance values of these forms, the Realizable k-ε model was chosen as the turbulence model, and the Volume of Fluid (VOF) method was applied. Resistance analyses were performed at five different speeds (5.5, 7.5, 9.5, 11.5, and 13.5 knots), within the Fn range of 0.15 to 0.40. Shear, pressure, and total resistance values were presented in both tables and graphs. The CFD resistance results were compared with those from the Holtrop and Fung resistance estimation methods, and the results were found to be consistent. Performance evaluations of the bulb shapes were made by comparing the friction, pressure, and total resistance coefficients. While the special bulb resulted in the greatest reduction in total resistance, the special-elliptical bulb demonstrated better performance across a wider range of speeds. It was also concluded that the traditional elliptical bulb type is unsuitable for this type of vessel.