Integral approach for modelling offshore bubble curtains

The construction of offshore wind turbine foundations in the North Sea with an impulsive hammer is related to high noise emission. For the protection of the maritime environment, the German government constituted limits of 160 dB in 750 m distance to the pile. To meet the regulations noise mitigation systems are used, especially the bubble curtain. Besides the intensive utilization of the bubble curtain, the main effect of the noise reduction has not been understood. A model of the bubble curtain has been developed which takes the local variation of the physical properties and the impact of the upper soil layers into account. Comparisons with offshore measurements are presented.