Investigation into the nonlinear hydroelastic response of an 8600-TEU containership model advancing in regular waves

Abstract

With the increase in the size of containerships, the lowest wet natural frequencies can be as low as 0.5 rad/s for vessels whose lengths are beyond 300 m. These lower frequencies make the estimation of wave loads when considering the hull flexibility quite challenging. Because no numerical tools are able to account for all of the nonlinear effects properly and there is not enough experimental data available for validation, the extent that current numerical tools can correctly predict the hydroelastic effects is a concern. This paper adopts a nonlinear hydroelastic code, WINSIR, to calculate the nonlinear hydroelastic response of an 8600-TEU containership model advancing in regular waves. The calculated results are compared with test data in terms of the first, second, third, fourth and fifth harmonics of the vertical bending moment amidships. Finally, the uncertainties in the experiments are discussed, and conclusions are given at the end of this paper.

Keywords:

• nonlinear hydroelastic response
• ultra-large container ship
• strip method
• model test
• vertical bending moment
• harmonic wave force

Acknowledgements

The authors wish to express their gratitude to the JIP participants for their financial support for the model tests. The experiments were conducted in the laboratories at the Marine Technology Centre in Trondheim with technical support and model test management by Ole Hermundstad at MARINTEK. The authors also acknowledge the financial support from the Research Council of Norway through CeSOS. Dr. MingKang Wu is thanked for providing his computer code WINSIR.