Comparison and hydrodynamic performance analysis of positioning bow type self-propelled cutter suction dredger aft hull lines

Objectives As the hydrodynamic performance of a positioning bow type self-propelled cutter suction dredger (CSD) is significantly different from that of an ordinary ship, this paper analyzes its performance in order to assist in the rational selection and design of stern lines.

Methods First, the computational fluid dynamics (CFD) method is applied to carry out simulation verification and model resistance test validation. On this basis, the hydrodynamic performance of two hulls with different stern shapes, namely twin deadwood and twin skeg, are compared and analyzed in aspects including calm water resistance behavior, stern wake field, axial wake fraction, and nonuniform level of axial wake field.

Results The total resistance coefficient of the twin skeg hull is lower than that of the twin deadwood hull at each target speed. At the design speed, the total resistance coefficient of the former is 8.6% lower than that of the latter, while the wake object function (WOF) of the latter is judged to be better than that of the former by 11.0% in terms of nonuniform level of axial wake field.

Conclusions The results of this study can provide valuable references for the line design and optimization of similar hull types.