Offshore Code Comparison Collaboration, Continued, with Correlation and unCertainty


The Offshore Code Comparison, Collaboration, Continued, with Correlation and unCertainty (OC6) is an international research project run under the International Energy Agency (IEA) Wind Task 30. The project is focused on validating the tools used to design offshore wind systems. OC6 implements a three-way validation process where both the engineering-level modeling tools and higher-fidelity tools are compared to measurement data. The results will be used to help inform the improvement of engineering-level models, and/or guide the development of future test campaigns.

The OC6 project consists of four phases to be performed over four years (2019-2023):

Phase Ia: Validate the nonlinear hydrodynamic loading on floating offshore wind support structures

Phase Ib: Additional data focused on Phase I from a component-level validation campaign geared towards CFD validation

Phase II: Develop and verify an advanced soil/structure interaction model for representing the pile/foundation interaction

Phase III: Validate the aerodynamic loading on a wind turbine rotor undergoing large motion caused by a floating support structure

Phase IV: Benchmark and validate methods for combining potential flow and viscous hydrodynamic load models for novel floating offshore wind support structures.

This website provides the data used for validation in these four phases, as well as simulation results from multiple participants.

Primary Contact(s)

Roger Bergua
National Renewable Energy Laboratory
Amy Robertson
National Renewable Energy Laboratory
Lu Wang
National Renewable Energy Laboratory


The objectives of OC6 are to:

• Perform a three-way validation of both engineering-level and higher-fidelity offshore wind modeling tools through the comparison of simulation results to measured data from a series of experimental campaigns focused on specific physical phenomena.

• Improve the physics of the offshore wind modeling tools based on both the outcomes of validation campaigns, and the technology innovations which require the expansion of the tools’ applicability and capabilities where limitations hinder technology advancement.

• Identify research and development needs beyond the scope of this project to better understand the physics of offshore wind systems and how to appropriately integrate these attributes into the modeling tools. This includes identifying the needs for future validation campaigns (i.e., need to better understand low-frequency nonlinear wave excitation) and significant improvements to the modeling tools (i.e., flexibility of the floating structure).


Starting: January 2019

Ending: December 2022


IEA Wind, Annex 30 - Task Extension Proposal, 2019-2022 OC6 (PDF)