Figure 6 - uploaded by Michael Smith
Content may be subject to copyright.
Source publication
NZS 6808 and other similar wind farm assessment standards require sound level measurements at neighbouring houses with and without the wind farm operating. While outlining a procedure for assessment using regression curves, the standards allow significant discretion in how the data are analysed. Issues with this analysis are reviewed and suggestion...
Context in source publication
Context 1
... inclusion of data outside of the critical range may disturb the fit of a polynomial curve. In other instances, the wider wind speed range may result in a better fit, as demonstrated in Figure 6. In general, a wider wind speed range is more likely to include different trends in sound level versus wind speed, requiring a higher order polynomial. ...
Similar publications
Despite the remarkable performance of Vision Transformers (ViTs) in various visual tasks, the expanding computation and model size of ViTs have increased the demand for improved efficiency during training and inference. To address the heavy computation and parameter drawbacks, quantization is frequently studied in the community as a representative...
This paper considers a robust piecewise linear regression model with an unknown number of change points. Our estimation framework mainly contains two steps: First, we combine the linearization technique with rank-based estimators to estimate the regression coefficients and the location of thresholds simultaneously, given a large number of change po...
In recent years, various accidents caused by pipeline corrosion and groundwater infiltration have brought irreparable losses to people’s lives and property safety. Therefore, it is very important to lay sensors on the pipeline for real-time monitoring and alarm. Aiming at the problem of distributed optical fiber sensing in the real-time pipeline mo...
How to facilitate users to quickly and accurately search for the text information they need is a current research hotspot. Text clustering can improve the efficiency of information search and is an effective text retrieval method. Keyword extraction and cluster center point selection are key issues in text clustering research. Common keyword extrac...
Citations
... At the Te Rere Hau review, it was argued that if 10% of measurements within a 1 m/s wide wind speed bin were tonal, then the penalty should be applied to the windspeed bin. This approach requires bin analysis [95,96], rather than polynomial regression. This approach was suggested because it would not overly penalise very infrequent occurrence of Special Acoustic Characteristics (SACs) but would apply an appropriate penalty to 'encourage mitigation' where SACs occur with reasonable regularity. ...
This manuscript describes a range of technical deliberations undertaken by the authors during their work as members of the Australian Government’s Independent Scientific Committee on Wind Turbines. Central to these deliberations was the requirement upon the committee to improve understanding and monitoring of the potential impacts of sound from wind turbines (including low frequency and infrasound) on health and the environment. The paper examines existing wind turbine sound limits, possible perceptual and physiological effects of wind turbine noise, aspects of the effects of wind turbine sound on sleep health and quality of life, low-frequency noise limits, the concept of annoyance including alternative causes of it and the potential for it to be affected by low-frequency noise, the influence of amplitude modulation and tonality, sound measurement and analysis and management strategies. In so doing it provides an objective basis for harmonisation across Australia of provisions for siting and monitoring of wind turbines, which currently vary from state to state, contributing to contention and potential inequities between Australians, depending on their place of residence.
... There are also many consultants and engineers in Australia and New Zealand who are undertaking excellent research, people like Tom Evans, Jon Cooper, Christophe Delaire and Colin Tickell amongst others in Australia, and Michael Smith and Stephen Chiles in New Zealand. These engineers are exploring new techniques to measure and assess noise from wind farms in a fair and equitable way [8][9][10], for example, by exploring 'bin analysis' of measured background and wind farm noise level [11] rather than the cumbersome 'regression' analysis which is usually adopted. ...
Some aspects of wind turbine noise generation can be best observed and understood by taking measurements in wind tunnels of noise from models of wind turbines complete with wind turbine blades and turbine blade sections. These tests are referred to as fixed-blade testing. Wind tunnel testing can remove some of the complicating factors related to atmospheric conditions. Also, scaling requirements result in higher rotor speeds and hence the frequency range of interest is not so low as to require specialised low-frequency microphones. The chapter focuses on wind tunnel testing and shows how to take acoustic measurements in wind tunnels, as aerodynamic and acoustic measurements are important when evaluating rotor blade sections. This includes single-microphone and acoustic-array measurements plus a summary of some recent wind tunnel measurements relevant to wind turbines. The chapter also focuses on recent acoustic-array testing of full-scale turbines.
Current wind farm noise regulations stipulate wind speed dependant criteria (referenced to wind speed at the hub height of the turbines), under the assumption that during high-wind speed conditions (when wind turbines generate higher noise levels), there will be a corresponding high wind speed and masking noise level at nearby receivers. However, under very stable conditions, high wind speeds at the turbine hub height will create significant noise, while low wind speeds at the receiver will not be sufficient to provide a masking effect. This has been considered in assessment guidelines by filtering day/night background data, but this approach ignores the impact of changes in the level and spectral content of turbine noise due to high shear velocities across turbine blades. This paper examines meteorological data in the vicinity of an undisclosed future wind farm site in South Australia, which was used to filter noise and wind speed data based on stability criterion, and discusses the potential impact on the noise criteria used for wind farm developments.
