An Aero-acoustic Noise Distribution Prediction Methodology for Offshore Wind Farms

Jiufa Cao,Weijun Zhu,Haoran Xu,Tongguang Wang,Xinbo Wu

doi:10.3390/en12010018

Jiufa Cao, Weijun Zhu + Show 3 more

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https://doi.org/10.3390/en12010018

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Abstract

Recently attention has been paid to wind farm noise due to its negative health impact, not only on human beings, but also to marine and terrestrial organisms. The current work proposes a numerical methodology to generate a numerical noise map for a given wind farm. Noise generation from single wind turbines as well as wind farms has its basis in the nature of aerodynamics, caused by the interactions between the incoming turbulent flow and the wind turbine blades. Hence, understanding the mechanisms of airfoil noise generation, demands access to sophisticated numerical tools. The processes of modeling wind farm noise include three steps: (1) The whole wind farm velocity distributions are modelled with an improved Jensen’s wake model; (2) The individual wind turbine’s noise is simulated by a semi-empirical wind turbine noise source model; (3) Propagations of noise from all wind turbines are carried out by solving the parabolic wave equation. In the paper, the wind farm wake effect from the Horns Rev wind farm is studied. Based on the resulted wind speed distributions in the wind farm, the wind turbine noise source and its propagation are simulated for the whole wind farm.

Highlights

With the fast increase of blade length as well as the number of wind farms, more environmental impact is expected to occur such as excessive wind turbine noise emissions
Previous works were more focused on individual wind turbine noise source predictions
Noise generated from offshore wind farms may travel kilometers to reach the nearby dwellers, but there are two facts which enhance offshore wind farm noise propagation: (1) no noise barrier exists over the propagation range; (2) the water surface is acoustically hard and almost fully reflective

Summary

Introduction

With the fast increase of blade length as well as the number of wind farms, more environmental impact is expected to occur such as excessive wind turbine noise emissions. Extraction of more energy from wind is obviously the key design target of wind farm developers. Due to the more pronounced wind farm noise issue, there is clearly a need to develop sophisticated design tools to fulfil the requirements of wind farm’s high power performance and low noise radiation. Previous works were more focused on individual wind turbine noise source predictions. For a long time wind turbine noise studies have been separated from wind turbine noise source generation and noise propagation. As wind farm noise has become an essential research topic, the objective of the current work is to couple a wind farm wake model with a wind farm noise source model and generate the wind farm noise map using a long range noise propagation method. Previous work done by Andersson [1] found out that species

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