Uncertainty analysis of a CFD solver for predicting ship motions in head waves

Rodrigues, M.I.P.; Wang, S.; Islam, H.; Abdelwahab, H.S.; Jiao, J.; Guedes Soares, C.

Key information

Authors:

Rodrigues, M.I.P. (Maria Inês Pinto Rodrigues); Wang, S. (Shan Wang); Islam, H. (Hafizul Islam); Abdelwahab, H.S. (Hossam Salah Youssef Abdelwahab); Jiao, J.; Guedes Soares, C. (Carlos Guedes Soares)

Published in

January 15, 2026

Abstract

This study quantifies simulation uncertainties arising from discretisation and modelling uncertainties in a CFD solver used to predict the motions of a containership in head waves at two forward speeds. Simulations were conducted in regular head waves with various wavelengths to predict the heave and pitch motions, viscous and total surge force, and the added resistance of the S175 containership using the OpenFOAM CFD solver. Numerical uncertainty assessment due to discretisation is performed using the factor of safety and correction factor approaches with a constant CourantFriedrichsLevy based approach. Most numerical outcomes exhibit monotonic convergence with low uncertainty levels. Transfer functions are calculated using three mesh resolutions, and comparisons with experimental data demonstrate satisfactory agreement. To systematically validate the numerical predictions, the experimental uncertainties are estimated using a simplified procedure based on available data in the literature. Modelling uncertainty is evaluated using the Frequency-Independent Model Error, Coefficient of Determination, and Modified Total Difference. The total simulation uncertainty combines contributions from discretisation and modelling uncertainties. The increased ship velocity does not significantly affects overall uncertainty. The correction factor approach consistently exhibits higher numerical uncertainty estimates than the safety factor approach across most analyses.