OC6 Phase Ia - Nonlinear hydrodynamic loading validation dataset

**Overview**

Two validation campaigns were examined within the Offshore Code Comparison Collaboration, Continued, with Correlation and unCertainty (OC6) Phase 1 project to examine the modeling tools' underprediction of loads and motion of a floating wind semisubmersible (semi) at their surge and pitch natural frequencies. These campaigns were performed at the Maritime Research Institute Netherlands (MARIN) in 2017 and 2018. The load cases (LC) considered include:

LC1 ? Load measurements across semi under current loading;

LC2 - Load measurements across semi under forced surge oscillation;

LC3 ? Load measurements across semi under wave loading, while held fixed;

LC4 ? Free-decay motion measurements in surge, pitch, and heave; and

LC5 ? Motion measurements under wave loading.

Details on the results from the OC6 Phase Ia project can be found in the reference, ?OC6 Phase 1: Investigating the underprediction of low-frequency hydrodynamic loads and responses of floating wind turbines?, J Phys: Conf Series 1618 032033.


**Data Details**

The naming of the datafiles follows the convention: oc6.phase1a.name.loadcase.txt. The experimental measurements use the name ?EXP0?. Simulation results are also provided from those that participated in the OC6 Phase Ia validation project. The suffix ?.txt? is replaced with ?.tot? and ?.hyd? and for load cases 1 and 2, representing the total load measurement, and just the hydrodynamic component.

**Data Quality**

The aim is to provide accurate and high-quality data. Whenever possible, instrumentation is calibrated by the manufacturer and then verified for use.

**Uncertainty**

A full assessment of the uncertainty in this dataset was performed, and findings were published in the paper, "Total experimental uncertainty in hydrodynamic testing of a semisubmersible wind turbine, considering numerical propagation of
systematic uncertainty," Ocean Engineering 195 (2020) 106605.