Wang, L.; Guo, C.; Su, Y.; Wu, T., and Wang, S., 2017. Numerical study of the viscous flow field mechanism for a non-geosim model.

Inasmuch as the scale effect of wake fields has not yet been resolved, the application of a “Smart Dummy” model in predicting the full-scale nominal wake field and propeller-induced hull pressure fluctuations of ships sailing in coastal environments and zones farther out to sea has shown great potential since the concept was first proposed. However, it still has not been widely used because the rules and mechanisms of the Smart Dummy model are seldom studied by international and domestic researchers. A non-geometrically similar model (non-geosim model) of the KRISO3600TEU Container Ship (KCS) was designed by employing a local parameterization modeling method based on computational fluid dynamics numerical simulation methods. Based on the viscous flow field mechanism, numerical analysis was performed on the ship resistance performance, free-surface wave pattern, hull volume-of-fluid distribution, hull streamlines, nominal wake field at the propeller plane, and stern axial velocity field. First, the accuracy of meshing and numerical methods was verified using grid-independent analysis. Subsequently, the same grid and methods were applied for the numerical simulation and analysis of towed bare hull and self-propelled ships. The results show that the free-surface wave pattern of the Smart Dummy model was almost identical with that of the geosim model, and the distribution of boundary layers around the hull shows that the Smart Dummy had thinner and more contracted velocity boundary layers after the deformation area. The stern streamline distribution further indicated that the Smart Dummy model had a more uniform propeller inflow velocity. The difference in the angle of attack of the propeller blade operating at the rear of the KCS model accounted for the overprediction of the propeller-induced hull pressure fluctuations using the geosim model. Overall, the new method proposed in this paper has important potential applications in predicting flow characteristics for large container ships sailing in coastal environments and zones farther out to sea.