UACE2017 Proceedings: A 3D far-field model for underwater pile driving noise

• Session:
  Three-dimensional sound propagation models and effects
• Paper:
  A 3D far-field model for underwater pile driving noise
• Author(s):
  Jonas Von Pein, Stephan Lippert, Otto Von Estorff
• Abstract:
  Within the last decade the ongoing industrial exploitation of the world’s oceans and especially the ongoing building of numerous offshore wind turbines has increased the number of foundations that are fastened to the seafloor by pile driving. These offshore pile driving activities lead to excessive underwater noise levels. In some areas, e.g. the German exclusive economic zone, dedicated limit values for the underwater noise levels have to be complied with in order to protect the marine fauna. To define the underwater noise emission and investigate the possible necessity of sound mitigation systems to decrease the noise levels, numerical prediction tools are essential. If the water depth does not considerably change within the construction site, 2D models are suitable. Corresponding numerical prediction tools have been developed and validated. These numerical models are rotationally symmetric and range independent. With the ongoing construction of offshore wind turbines and the development of floating offshore wind turbines for deeper locations, more complex sites will be used for pile driving in the future. Therefore, 3D models that take a varying bathymetry and range dependant parameters into account become more and more important. Within this paper, the split-step parabolic equation (PE) method will be used for a 2D model and extended to a 3D model accounting for azimuthal variations. The 2D results are verified and validated with the results of a Wavenumber Integration (WI) model and corresponding measurements from the BORA project. To exemplarily show the effects of varying bathymetry the same set-up is used with a slightly sloping sea floor and calculated with a 3D simulation. The resulting SPL and SEL of the corresponding 2D and 3D simulations are compared and the next steps to reduce the computational effort are described. \n
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Contact details

• Contact person:
  Mr Jonas von Pein
• e-mail:
  
• Affiliation:
  Hamburg University of Technology
• Country:
  Germany