installation at Dudgeon Offshore Wind Farm

steep and breaking waves, and specifically on the possible scale effects on model test results. Tone says: “Presently, the design values of such loads are mainly based on model test data. This means that quantifying uncertainties from the model test results is very important when designing new plat- forms. Wave impact on large-volume columns is a topic Statoil has been interested in for some time, and the scale effects, including air entrapment and entrainment is a very important piece of the puzzle.”

Extreme events MARIN is initiating several JIPs in the field of extreme event analysis, with regard to model testing techniques but also for numerical simula- tions. Which analysis methodologies does Statoil foresee in the future for the field of extreme event analysis? Tone comments: “I guess the enabler for a lot of the improvement in model testing in the last 5-10 years is the

enormous increase in computer capacity, so we can collect and store data from a large number of channels with increasing sampling frequency. Another improvement is the use of high-speed cameras triggered by specific events. This is very useful for understanding violent flow phenomena. All this means we get a lot more information from model tests than we did before. Increased automation of wave calibration and 3D modelling have for example, made the preparation of models and waves more effective.”

But she stresses that there is still room for improvement and new innovations. There are interesting developments going on regarding hybrid testing (coupled simulations and testing), which seems to be very promising for testing wind turbines for instance, says Tone. “Additionally, the combination of model testing and CFD simulations is an area where I foresee a lot of development in the future. Measuring

the wave kinematics during testing in an ocean basin is a challenge that has proved difficult. Here, CFD may be the answer, but I am also still hoping for direct measuring methods.”

CFD & numerical simulations When considering the future role of CFD and numerical simulations for extreme events’ analysis Tone expects that their use will increase as industry design and verification tools, but she is not sure they will be replacing model tests completely. “I think it is important to combine analytical, computational and experimental tools to catch all the important physical effects, especially when looking at extreme wave events. The benefit of CFD is that a lot more information of the flow is obtained than from model testing, where we only get the information we can physically measure at specific positions decided prior

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