Prediction of Seabed Scour Induced by Full-Scale Darrieus-Type Tidal Current Turbine

Abstract

Scour induced by a Darrieus-type tidal current turbine was investigated by using a joint numerical and experimental method with emphasis on the scour process of a full-scale turbine. This work proposes a new numerical method to estimate turbine scour developments, followed by model validation through experimental data in the initial stage. The small-scale numerical model was further extended to a full-scale model for the prediction of turbine scour. The numerical model consists of (1) k-ω turbulence closure, (2) a sediment transport model, and (3) a sediment slide model. The transient-state model was coupled with a morphologic model to calculate scour development. A dynamic mesh updating technique was implemented, enabling the autoupdate of data for the grid nodes of the seabed at each time step. Comparisons between the numerical results and the experimental measurements showed that the proposed model was able to capture the main features of the scour process. However, the numerical model underestimated about 15%–20% of the equilibrium scour depth than experimental data. An investigation of the temporal and spatial development of seabed scour around a full-scale Darrieus-type tidal current turbine is demonstrated. This work concludes that the proposed numerical model can effectively predict the scour process of tidal current turbines, and the rotating rotor has a significant impact on the equilibrium scour depth for full-scale turbines.

Hydrodynamics and Tidal Turbine Generator Stability Analysis in Several Wave Variations

“…Simulation scale models were expanded to large-scale models for turbine scour estimation. However, the simulation misses the estimated about 15-20% based on field-based data [20].…”

A feasibility study of reducing scour around monopile foundation using a tidal current turbine

“…It may vary from time to time. In order to ensure that the TCT can work effectively all the time and avoid the scour effects due to propeller jet velocities [26] [27] and the negative impact of TCT on reducing scour pit depths [28] [29], the TCT will be suspended from a rotating platform, which can rotate around the monopile foundation of the OWT to ensure that the rotor plane of the TCT always faces the direction of the tidal current. The schematic diagram of the proposed technique is shown in Fig.2.…”