Marine animal welfare requirements regarding maximum pile driving noise for offshore wind platforms can slow down construction projects. Novicos is working on the development of new technical solutions for noise reduction when driving foundations for offshore wind farms (OWF), mainly using simulation techniques.
Complex processes
Existing noise protection concepts are subject to weather restrictions, among other things. This can lead to delays in construction work and extended rental periods for large offshore equipment. Sometimes it jeopardizes the entire construction project of an OWP.
Noise reduction measures during pile-driving work for offshore wind farms
The guideline values required by the Federal Environment Agency (UBA) (160 dB re 1 μ Pa for the single event sound pressure level, 190 dB re 1 μ Pa for the peak level) are still generally significantly exceeded today. In the North Sea, sound pressure levels of 235 dB were measured at the source (pile driver) during the pile-driving of steel monopiles at the Horns Reef wind farm.
Calculation models for forecasting the reduction effect
The informative value of such models should cover a frequency range from 10 Hz to 10 kHz. However, discretization methods for extended investigation areas quickly reach their limits with regard to the size of the resulting equation systems. The resulting problems are largely unsolved and, in addition to modeling the bubble curtain, represent the major showstopper in the simulation.
Our contribution to quieter pile driving
-
Solution to the entire problem
Modeling for coupled vibro-acoustic systems, propagation calculations in (semi-)infinite areas and large models with several hundred thousand degrees of freedom.
-
Consideration of bubble drift under flow
Our experience with flow simulation and particle drift in the sea enables us to calculate flow influences.
-
Creation of FE-based pile modeling
A pile model is used to determine acoustically relevant parameters such as the surface velocities and the pore water pressure at the interfaces between the water and the pile or seabed.
-
Acoustic model
The results of a pile model are used as input variables for the acoustic model to predict the acoustic parameters in the near and far field of the pile.
-
Acoustic simulations in the far field
Boundary Element Method (BEM), the Perfectly Matched Layer technology or the ray tracing method.
Do you have any questions about this article?
I will be happy to answer any questions you may have.
