Session: 09-04-01 Wind Energy: Monopile structures

Submission Number: 157208

Innovative Hydrodynamic Research Facilities for Offshore Renewable Energy: a Case Study on the Effects of Biofouling 

Experimental testing of offshore renewable energy (ORE) systems (ocean wave energy, floating offshore wind, etc.) in all stages along the TRL-TLP development trajectory is paramount to gain insights into the dynamic behaviour, survivability, and other aspects of the design. In concert with numerical modelling techniques, physical wave tank and flume tests provide the necessary information for proof of concepts, design optimisation, or design of energy maximising control strategies. In particular, experimental test facilities provide the opportunity to test ORE systems in realistic and, most importantly, controlled environments. Available test facilities mostly differ in terms of their operational parameter space, e.g., maximum wave heights, maximum water depths, maximum model scales, the ability to model wave-current interaction or climate conditions. At TU Braunschweig and the Coastal Research Centre, Hannover, a number of novel experimental research facilities recently became available for testing of ORE systems. These facilities, namely a Saltwater Wave-Current Flume (SWCF) and the Large Wave Current Flume (GWK+), show specific features which distinguish them from already existing facilities. The SWCF allows testing of devices in a seawater environment with full control over the aquatic boundary conditions, thereby enabling the testing of the influence of live marine growth on the system dynamics. In addition, the implementation of two wave makers (for generation and active absorption in two different directions) together with powerful current generation allow testing of a wide range of hydraulic boundary conditions. The GWK+ is unique in its ability to test devices at large scale in harsh offshore environments. With its dimensions (300 m × 7 m × 5 m, length × depth × width) and powerful wave (up to 3 m) and current (up to 20 m³s^-1) generation, this facility can replicate realistic extreme conditions in a lab. The additional deep section (up to 6 m depth) allows the installation of realistic mooring system.

This paper will present in detail the capabilities and features of the novel research facilities, thereby highlighting their potential to enhance the modelling and analysis of ORE system, filling current knowledge gaps, and push systems forward on the TRL-TLP development trajectory. A case study on the analysis of live marine growth on the monopile of an offshore wind turbine showcases the specific features, providing unique data and unprecedented results.

Presenting Author: Nils Goseberg Technische Universität Braunschweig

Presenting Author Biography: Since 2018, I am working at Technical Universität Braunschweig as a professor of hydromechanics, coastal and ocean engineering, heading a division of the Leichtweiß-Institute for Hydraulic Engineering and Water Resources. I am also the deputy managing director of the Coastal Research Center (Forschungszentrum Küste), a joint research facility with Leibniz University Hannover.