Model uncertainty in hydrodynamic characteristics by numerical models for aquaculture plant and mooring system

The aquaculture plant with a mooring system is a relatively novel concept compared with the traditional offshore structures and plenty of numerical models have been proposed to investigate its hydrodynamic behavior. In this study, the model uncertainty in hydrodynamic characteristics by several existing numerical models is estimated based on the validation data in the published researches. The traditional method is employed to calculate the statistics of the model bias factor and the bootstrap method is used to estimate the statistical uncertainty in the model bias factor due to the small sample size. In addition, the reliability analysis of mooring line is conducted considering the model uncertainty for a case study. The results indicate that the bootstrap method can effectively predict the uncertainty of the mean value and the standard deviation of the model bias factor and the model uncertainty can significantly affect the reliability of the mooring line. The bootstrap confidence interval of the reliability index can be calculated to achieve a more reasonable assessment of the failure probability for the designers. Therefore, the characterization of the statistical uncertainty in the model bias factor is of paramount importance for the reliability-based design of the aquaculture plant and its mooring system.

Automated summary

This study estimated the model uncertainty in hydrodynamic characteristics by existing numerical models and effectively predicted the uncertainty of the model bias factor using the bootstrap method. The results show that model uncertainty can significantly affect the reliability of the mooring line, and bootstrap method can provide a more reasonable assessment of the failure probability.