SCOUR MECHANISM AROUND UMBRELLA SUCTION ANCHOR FOUNDATION FOR OFFSHORE WIND TURBINE IN WAVES

Hu Ruigeng; Liu Hongjun; Wang Xiuhai; Zhao Zhen; Shi Wei

doi:10.19912/j.0254-0096.tynxb.2021-0490

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Acta Energiae Solaris Sinica ›› 2022, Vol. 43 ›› Issue (11) : 242-252. DOI: 10.19912/j.0254-0096.tynxb.2021-0490

SCOUR MECHANISM AROUND UMBRELLA SUCTION ANCHOR FOUNDATION FOR OFFSHORE WIND TURBINE IN WAVES

Hu Ruigeng¹, Liu Hongjun^1~3, Wang Xiuhai^1~3, Zhao Zhen¹, Shi Wei⁴

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Abstract

A series of wave flume experiments and numerical simulation were conducted under waves, so as to investigate the scour mechanism around umbrella suction anchor foundation （USAF） of offshore wind turbines. Then, two revised models were proposed according to the model of Raaijmakers and Myrhaug model respectively to predict the equilibrium scour depth around USAF for low Keulegan-Carpenter number （KC） under waves. The results indicated that the vortex system at wave crest phase is mainly responsible for the scour process under waves. What's more, due to the combination of the horseshoe vortex and streamline compression, the maximum scour depth occurred at the upside of the USAF with an angle of about 45° corresponding to the wave propagating direction. The tube skirt and anchor branches play a role in protecting the scour around USAF to some extent. The revision model based on Raaijmakers's model shows good agreement with the simulating results of the present study for KCs,p<8. However, the gap between the predicting results and experimental data becomes large and the Eq.（25） overestimates the equilibrium scour depth to some extent for KCs,p>8. The predicting results of another revision model based on the stochastic model are the most favorable for n=10 when KCrms,a<4.

Key words

scour / equilibrium scour depth / KC number / offshore wind turbine foundation

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Hu Ruigeng, Liu Hongjun, Wang Xiuhai, Zhao Zhen, Shi Wei. SCOUR MECHANISM AROUND UMBRELLA SUCTION ANCHOR FOUNDATION FOR OFFSHORE WIND TURBINE IN WAVES[J]. Acta Energiae Solaris Sinica. 2022, 43(11): 242-252 https://doi.org/10.19912/j.0254-0096.tynxb.2021-0490

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