
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 during foundation pile driving for offshore wind farms (OWPs), mainly using simulation techniques.
Elaborate 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 offshore large-scale equipment. Sometimes it jeopardizes the entire construction project of an OWP.
Noise reduction measures during pile driving for offshore wind farms
The guide values required by the German 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) have generally been considerably exceeded to date. In the North Sea, sound pressure levels at the source (pile driver) of 235 dB were measured during the pile driving of steel monopiles at the Horns Reef wind farm.
Calculation models for forecasting the reduction effect
The expressiveness 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 here with respect to the size of the resulting systems of equations. The resulting problems are largely unsolved and represent the major showstopper in the simulation besides the modeling of the bubble veil.
Our contribution to quieter pile driving
-
Solution of the whole problem
Model building for coupled vibro-acoustic systems, propagation calculations in (semi-)infinite domains, 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 ocean allows us to calculate flow effects.
-
Creation of FE-based pile modeling
A pile model is used to determine acoustically relevant quantities, such as the surface velocities and the pore water pressure at the interfaces between water and pile or seafloor.
-
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 even the ray tracing method.
Do you have questions about this article?
I am happy to be there for you and answer your questions.
