Now Hear This! What All Environmental Engineers Should Know About Noise Control

Noise is an is an that affects almost everyone. And even though environmental engineers are often called on to deal with noise-related problems, most of them receive little or no academic training in noise control. This primer suggests why all environmental engineers should know something about noise control, what they need to know, and where they can find the necessary information

WIND TURBINE GENERATOR NOISE PREDICTION -COMPARISON OF COMPUTER MODELS

Abstract The development of wind turbine generators as alternative sources of energy supply is a growing fact both in Australia and worldwide. One of the many aspects of the environmental impact assessment process for new wind farms is the prediction of their noise impacts (immissions). As well as the assessment of objective sound levels for environmental noise, the other main activity in assessing their noise impact is the prediction of receiver sound levels caused by emissions of noise from the wind turbine generators (WTG's). There are a number of computer noise models available for the prediction of environmental noise, as well as some specifically designed for noise emissions from WTG's. This paper presents the results of modeling for a typical wind turbine generator using three different prediction models. There is a significant difference between the predicted results using a noise model designed for static industrial sources, compared to algorithms or models designed specifically for WTG's. The main difference appears to be the method in which elevated sources are computed. A significant contributor to WTG noise is aerodynamic noise from each blade tip. These blades can vary in height by as much as 80m per revolution and have an axis 60 to 80m above ground. Wind farm noise emissions also increase with wind speed (typically from 4 to 12m/s), as does associated background noise. This makes the monitoring of background sound levels over the range of operating wind conditions also important. Selection of accurate prediction models for WTG's will enable a better assessment of the noise impacts from wind farms to be made

What Should Environmental Engineers Know About Noise Control?

Noise is an issue that affects everyone. It is a problem that often becomes the responsibility of Environmental Engineers. Currently, most receive little academic training in Noise Control. This paper explores the reasons why Environmental Engineers need to know something about noise and what they need to know. In addition to recommending that graduating Environmental Engineers are exposed to Noise Control, this paper suggests some available resources