Task 39 Publications

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The goal of IEA Wind TCP Task 39 is to accelerate the development and deployment of quiet wind turbine technology. The task will convene an international expert panel to exchange learning, identify and report best practices in the measurement and assessment of noise.

Work Programmes

As part of the WP1 Interdisciplinary Education and Guidance, a number of documents are being drafted and will be released when reviewed and approved by the participants of Task 39.

A summary of the work programme for Phase 1 can be downloaded here.

The new work programme for Phase 2 can be downloaded here.

Fact Sheets

As part of the WP1 Interdisciplinary Education and Guidance, a number of documents are being drafted and will be released when reviewed and approved by the participants of Task 39.

A fact sheet on wind turbine noise Amplitude Modulation is available here.

A fact sheet on wind turbine Low Frequency Noise is available here.

Technical Reports

A number of documents reporting the different on-going Task 39 activities are available here.

This document aims at providing technical guidance for measuring wind turbine noise, focusing on noise propagation effects. It is however not a step-by-step technical guide on how to conduct a wind turbine noise measurement campaign. Rather, it takes the form of an exhaustive list of information that should be documented in addition to the acoustic measurement data themselves. These information are categorized into a number of topics. The objectives are to improve the content of the resulting measurement dataset (e.g. by increasing its completeness), as well as prepare and facilitate the post-processing of the measured data and their interpretation during a subsequent scientific analysis. Some specifications for the measuring equipment is also provided that should also contribute to the latter objectives.

This document has been drafted as an Expert Group Study report by the participants of Task 39 – WP3, which focuses on wind turbine noise propagation issues. An Experts Group Studies report includes the latest background information on the topic as well as a survey of practices, where possible.

A wind turbine noise prediction codes benchmark was initiated during Phase 1 of Task 39. This benchmark is joined to a similar effort conducted as part of Task 29. Task 29 is mainly concerned with aerodynamic and aeroelastic features but it also has a WP dedicated to acoustics. Here, the focus is on aerodynamic noise generation, hence mechanical noise, as well as long-range propagation effects, are not considered, at least in the first phase of this benchmark. The current status of this ongoing work is available here.

A benchmark was initiated about noise measurements on serrated airfoil trailing edges. Trailing edge serrations have been widely used to reduce the trailing edge noise of wind turbine blades. However, large uncertainties in terms of analytical and computational modeling as well as testing do persist. The challenges in wind tunnel testing are found in the low signal-to-noise ratio because an aerofoil equipped with trailing edge serration is very quiet and
background noise in the aeroacoustic test setup can become dominant.

Three leading groups working with aeroacoustics (5 wind tunnel test facilities in total) in Europe joined forces to quantify these uncertainties in testing. The participating institutions are the Technical University of Denmark (DTU, DK), the German Space Agency (DLR, DE), and the Delft University of Technology (TU Delft, NL). The strategy was to test the same aerofoil model in the different facilities in order to compare results and quantify the spread of the data. Furthermore, the data set should be published as a reference for benchmarking computational models. It is planned to use the BANC framework for this purpose. The current status of this benchmark is reported here.

Publications in Conferences and Journals

Various of the Task 39 activities have been presented in scientific conferences.

The IEA Wind TCP and Task 39 framework and its activities were presented as a poster during the Wind Turbine Noise 2019 conference.

The wind turbine noise code benchmark was introduced with an oral presentation at the Wind Turbine Noise 2019 conference, and published in the proceedings provided here.

A collaboration work has been initiated between Task 19 (Cold Climate) and Task 39. This study is concerned with a review of potential additional noise generated by icing on the blades. A numerical study is also conducted in an attempt to qualitatively evaluate increased noise levels. This collaboration resulted in a joined Tasks 19-39 presentation at the Winterwind International Wind Energy Conference in April 2021. The slides are available here.


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