Numerical Study of the Effect of River-Sea Ship Hull Form Parameters on Resistance and Their Optimisation Using the Taguchi-Grey Method

In this paper, we systematically investigate the effect of the five most important ship hull form parameters, namely the longitudinal centre of buoyancy (LCB), the half angle of entrance of the design waterline ((½))αE), and the length (C_LPR), cross-section (C_ABT) and volume (C_∇PR) parameters for the bulbous bow on the ship resistance using a computational fluid dynamics method. The parent ship hull form investigated in this study is a 4600DWT cargo ship, which operates on Vietnam’s river-sea routes. To save time and reduce costs, only 25 test cases designed with the orthogonal array Taguchi method are simulated, and the resistance is calculated in deep and shallow water at speeds of 10.0 and 9.0 knots, respectively. The optimal combination of the five ship hull form parameters is obtained using Taguchi-grey relational analysis. The results indicate that the optimum ship hull form depends on the water depth, and that LCB is the most critical parameter in regard to resistance. Of the combinations studied here, the variant with (½)αE=42°, CLPR=0.0141, C_ABT=0.1600, C_∇PR=0.00173, LCB=48.654%L_BP is found to be optimal.