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Comparison analysis of noise generated by wind turbines with the other noise source in outdoor environment

Staniek Andrzej, Kompała Janusz, Bramorska Alicja, Bartmański Cezary

Vibrations in Physical Systems

2023

Vol. 34, nr 1

art. no. 2023108

The paper presents a comparison analysis of the noise generated by wind turbines and the one generated by a ventilation shaft of a working coal mine. The aim of the research was to compare the frequency and amplitude distribution of those sources, especially in the infra range. The ultimate aim it is evaluate possible environmental impact on human annoyance or severity. During the research noise signals were recorded utilizing low frequency microphones, shielded by windscreens. Microphones were localized at the heights of 0.0 m, 1.5 m (approximate location of a human ear in a standing position) and 4 m. Additionally, a measurement position of a microphone in relation to the ground surface was observed. Measurements at ground level were performed according to the standard PN-EN 61400-11:2013-07 and in vertical position, where the microphone was mounted "upside down" with the grid flush with the board. The possible influence of wind speed was also monitored. The results of the measurements are discussed.

Side Effect of the Use of Acoustic Barriers Observed in the Infra Range

Staniek Andrzej, Bartmański Cezary

Archives of Acoustics

2020

Vol. 45, No. 1

103--110

Acoustic barriers which are positioned along traffic lanes are designed to protect the surroundings from excessive noise. Such structures are to reverberate, diffract and damp the propagating acoustic waves. However, this method of shielding has some disadvantages which include constraint visibility and structure-born noise. The interaction between traffic-caused movement of air mass and acoustic barriers may generate infra noise waves. That is undesirable and should be estimated. The authors undertook the research to diagnose the plausible side effect of structure-born noise of such barriers because it may influence human body (Kasprzak, 2014). As a mechanical structure, the acoustic barrier is characterized by mechanical parameters which, in the field of modal analysis, are made up of natural frequencies, damping factors and mode shapes. In this paper the authors investigated the acoustic pressure distribution in the neighborhood of a real acoustic barrier in the scope of infra noise propagation. The methods of modal analysis were used to identify natural frequencies of the barrier and dominating frequencies of propagating waves in the far field. The correlation between observed vibration and acoustic signals is presented.