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Subjective assessment of wind turbine noise annoyance - tests in laboratory conditions

Pleban Dariusz, Szczepański Grzegorz, Kapica Łukasz, Alikowski Adrian, Łada Krzysztof, Włudarczyk Anna

Vibrations in Physical Systems

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2023

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Vol. 34, nr 2

art. no. 2023208

EN

The constant growth of energy demand, as well as the accompanying increase in environmental pollution resulting from the prevailing use of fossil fuels, has led to a rising use of energy from renewable sources. The use of wind turbines to generate electricity has many obvious advantages, such as lack of fuel costs during operation and lack of harmful pollutants, including carbon dioxide. Despite advantages, the use of wind turbines constantly raises questions concerning the impact of wind farms on humans. This impact includes many factors related to the operation of wind farms, and in particular noise emitted by these farms. The wind turbine noise impact on humans has been studied by the Central Institute for Labour Protection - National Research Institute. A test bench to conduct noise annoyance tests of different types of wind turbine noise in laboratory conditions have been developed. During exposures to 6 different virtual acoustic environments, representing different wind turbine noise, 40 participants assessed wind turbine noise annoyance. The paper describes the results of the studies concerning the assessment of wind turbine noise annoyance.

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Sprawdzenie przydatności metamateriału akustycznego do redukowania hałasu średnio- i wysokoczęstotliwościowego - symulacje numeryczne

Szczepański Grzegorz, Podleśna Marlena, Łada Krzysztof, Włudarczyk Anna

Bezpieczeństwo Pracy : nauka i praktyka

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2023

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nr 4

22-27

PL

Hałas na stanowiskach pracy wciąż jest głównym zagrożeniem dla pracowników zakładów przemysłowych. Zastosowanie obudów i barier dźwiękoizolacyjnych w celu ograniczania tego zagrożenia nie zawsze jest możliwe lub wystarczające. Stosunkowo nowym i obiecującym sposobem redukcji hałasu jest wykorzystanie metamateriałów akustycznych, które przekierowują bądź pochłaniają falę dźwiękową, a najwyższą skuteczność wykazują przy częstotliwości bliskiej częstotliwości rezonansowej. Metamateriały akustyczne służą przede wszystkim do redukcji hałasu wąskopasmowego. W artykule przedstawiono ich modele numeryczne, które posłużyły do wyznaczenia częstotliwości rezonansowych. Symulacje przeprowadzono w dwóch różnych programach przeznaczonych do analizy metodą elementów skończonych (MES). Otrzymane wyniki wskazują, że metamateriał o strukturze tunelowej z umieszczonymi wewnątrz rezonatorami Helmholtza może redukować hałas w kilku pasmach częstotliwości (w zakresie średnio- i wysokoczęstotliwościowym) oraz w większym stopniu niż metamateriał o strukturze tunelowej bez rezonatorów.

EN

Noise in workplace environments is still the main risk factor for workers in industrial plants. The use of sound insulation enclosures and soundproof barriers to reduce this risk is not always possible or sufficient. A relatively new solution used to reduce noise are acoustic metamaterials that redirect or absorb the sound wave, and show the highest efficiency at frequencies close to the resonant frequency. They are primarily used for narrowband noise. The article presents the developed numerical models which were used to determine the resonant frequencies. Simulations were performed in two different programs based on finite element method (FEM). The obtained results indicate that the tunnel structure with Helmholtz resonators placed within can suppress the noise in several frequency bands (mid-frequency and high-frequency range) and to a greater extent than tunnel structures without resonators.

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Investigation of the Acoustic Properties of a Metamaterial with a Multi-Ring Structure

Szczepański Grzegorz, Podleśna Marlena, Morzyński Leszek, Włudarczyk Anna

Archives of Acoustics

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2023

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Vol. 48, No. 4

497--507

EN

In this article, the authors present the geometry and measurements of the properties of an acoustic metamaterial with a structure composed of multiple concentric rings. CAD models of the structure were developed and subsequently used in numerical studies, which included the study of resonant frequencies using the Lanczos method and an analysis of sound pressure level distribution under plane wave excitation using the finite element method. Subsequently, experimental tests were carried out on models with the same geometry produced with three different materials (PLA, PET-G, and FLEX) using a fused deposition modeling 3D printing technique. These tests included: determining insertion loss for a single model based on tests using the measurement window of a reverberation chamber and determining transmission loss through tests in a semi-anechoic chamber. Sound wave resonance was obtained for frequencies ranging from 1700 to 6000 Hz. Notably, the experimental studies were carried out for the same structure for which numerical tests were conducted. The physical models of a metamaterial were manufactured using three different readily available 3D printing materials. The results of laboratory tests confirm that the created acoustic metamaterial consisting of multi-ring structures reduces noise in medium and high frequencies.