Efficacia dei parametri geometrici del bulbo, ai fini della riduzione della resistenza al moto

The size and shape of a bulb bow can be defined by means of some significant geometrical parameters. Many scientific studies have shown that the utilization of a bulb modifies both the wave-making and the form resistance of the hull. In our study we have analyzed the variations of the coefficients of the two resistance components when some geometrical parameters of the bulb are modified. Ten different bulbs have been fitted on the hull of a warship model. In this case the study has shown that there are some parameters which exert greater influence on the reduction of the form resistance, whereas others lead to more considerable variations in the wave-making resistance. The study, which has also searched the different trims and the bow flow lines, enables us to have a better understanding of the effect of the bulb on the reduction of resistance.