Uncertainties in seakeeping analysis and related loads and response procedures

•Uncertainty analysis in seakeeping analysis is introduced.•The concept of ITTC׳s uncertainty analysis is described.•Uncertainty types and error sources in seakeeping experiment and computation are summarized.•Some examples of uncertainty analysis in seakeeping experiment and numerical computation are shown.

This paper presents the uncertainties in seakeeping analysis and the related International Towing Tank Conference (ITTC) procedures for loads and responses for waves. One of the emerging issues in ITTC activities is uncertainty analysis. ITTC (2008) has published a report with recommendations for uncertainty analysis for ship model testing, which summarized the fundamentals and examples of uncertainty analysis. Furthermore, a specific description focusing on seakeeping experiments was introduced by the Seakeeping Committee (2011) in their procedure, 7.5-02 07-02.1 Rev. 4, ITTC – Recommended Procedures and Guidelines: Seakeeping Experiments. This procedure is based on the International Organization for Standardization Guide 98-3, Uncertainty of Measurements – Part 3 (2008). In this paper, the uncertainties in seakeeping analysis are considered, and technical issues regarding the related ITTC procedure for motion responses and loads are introduced. Next, the background of uncertainty analysis in the ITTC procedure 7.5-02 07-02.1 Rev. 4 is described in detail. The types and primary sources of uncertainty in seakeeping analysis are also described, and an appropriate procedure is proposed. Some existing representative studies on uncertainty, which were carried out with respect to seakeeping analysis, are introduced. Furthermore, this paper includes several technical issues with numerical seakeeping and loads analyses.