# Kármán vortex and turbulent wake generation by wind park piles

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## Abstract

Observational evidence of turbulent wakes behind wind parks’ piles motivated a series of numerical experiments, aiming to identify the dynamic regimes associated with wakes’ generation in tidal basins. We demonstrate that the obstacles such as piles of wind parks give rise to vortices similar to the known Kármán vortices which affect substantially the turbulent kinetic energy. The latter can be considered as the agent enhancing sediment remobilization from the ocean bottom, thus making wakes well visible in satellite data. The temporal and spatial variability of studied processes is analyzed under stationary and nonstationary conditions. The dependence of a vortex generation and evolution upon the environmental conditions is also studied, which demonstrates a large variety of appearances of turbulent wakes. The comparison between simulations using a suspended sediment model and satellite images demonstrated that the model is capable to realistically simulate sediment wakes observed in remote sensing data.

## Keywords

Kármán vortex street Turbulent wake generation Wind park Numerical modeling## Notes

### Acknowledgments

We are grateful to Y.J. Zhang for making the model SCHISM and the original setup of Lloyd and Stansby (1997b) available. Thanks are due to the two referees for the useful comments and for the video made available by one of them showing similar dynamics to what is simulated in the paper. S. Grashorn is funded by the initiative Earth Science Knowledge Platform (ESKP) operated by the Helmholtz Association. The authors gratefully acknowledge the computing time granted by the John von Neumann Institute for Computing (NIC) and provided on the supercomputers JUROPA and JURECA at Jülich Supercomputing Centre (JSC). Figure 1 was taken from the publications of Vanhellemont and Ruddick (2014a, b), and Fig. 12a was taken from Lloyd and Stansby (1997a).

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