Search

Your search keyword '"Makarewicz, Rufin"' showing total 163 results
Start Over Author "Makarewicz, Rufin"
163 results on '"Makarewicz, Rufin"'

1. Influence of refraction on wind turbine noise

Author

Makarewicz, Rufin

Subjects
Physics - Atmospheric and Oceanic Physics, Physics - Classical Physics
Abstract

A semi-empirical method is applied to calculate the time-average sound level of wind turbine noise generation and propagation. Both are affected by wind shear refraction. Under upwind conditions the partially ensonified zone separates the fully ensonified zone (close to the turbine) and the shadow zone (far away from the turbine). Refraction is described in terms of the wind speed linear profile fitted to the power law profile. The rotating blades are treated as a two-dimensional circular source in the vertical plane. Inside the partially ensonified zone the effective A-weighted sound power decreases to zero when the receiver moves from the turbine toward the shadow zone. The presented results would be useful in practical applications to give a quick estimate of the effect of refraction on wind turbine noise., Comment: 17 pages, 8 figures, submitted to International Journal of Aeroacoustics

Published
2013

2. Amplitude modulation of wind turbine noise

Author

Makarewicz, Rufin and Golebiewski, Roman

Subjects
Physics - Atmospheric and Oceanic Physics
Abstract

Due to swish and thump amplitude modulation, the noise of wind turbines cause more annoyance than other environmental noise of the same average level. The wind shear accounts for the thump modulation (van den Berg effect). Making use of the wind speed measurements at the hub height, as well as at the top and the bottom of the rotor disc (Fig.1), the non-standard wind profile is applied. It causes variations in the A-weighted sound pressure level, LpA. The difference between the maximum and minimum of LpA characterizes thump modulation (Fig.2)., Comment: 13 pages, 8 figures, submitted to Acta Acustica united with Acustica

Published
2013

9. Corrected Long-Term Time-Average Sound Level of Amplitude-Modulated Wind Turbine Noise.

Author

MAKAREWICZ, Rufin and BUSZKIEWICZ, Maciej

Subjects
*WIND turbines, *AMPLITUDE modulation, *NOISE
Abstract

Amplitude-modulated noise from a single wind turbine is considered. The time-varying modulation depth Dm and the short time-average sound level LAeq, τ; (with τ = 20 s) are measured at the reference distance d* Due to amplitude modulation, a penalty has to be added to LAeq, τ. The paper shows how to calculate the corrected long-term time-average sound level LAeq;,Τ (with Τ >> 20 s), which accounts for amplitude modulation at any distance d ≠ d* from the wind turbine. The proposed methodology needs to be tested by research. [ABSTRACT FROM AUTHOR]

Published
2023
Full Text
View/download PDF

11. Proposed Methodology for the Annoyance Penalty of Amplitude Modulated Wind Turbine Noise.

Author

MAKAREWICZ, Rufin

Subjects
*WIND turbines, *DISCONTENT, *AMPLITUDE modulation, *NOISE
Abstract

Amplitude modulation increases the annoyance caused by wind turbine noise. One gets the improved annoyance when a penalty is added to the measured or calculated time-average sound level. The amplitude modulated wind turbine noise consists of pulses. Each of them could be characterized by the short timeaverage sound level and the modulation depth. The latter determines the pulse penalty. This paper shows how to calculate the improved annoyance of amplitude modulated wind turbine noise, when the short time-average sound level and the penalty for each pulse are known. A special case of identical pulses is discussed. The proposed methodology needs to be tested by research. [ABSTRACT FROM AUTHOR]

Published
2022
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results