Application of a ray theory model to the prediction of noise emissions from isolated wind turbines and wind parks

Prospathopoulos, JM; Voutsinas, SG

dc.contributor.author	Prospathopoulos, JM	en
dc.contributor.author	Voutsinas, SG	en
dc.date.accessioned	2014-03-01T01:25:56Z
dc.date.available	2014-03-01T01:25:56Z
dc.date.issued	2007	en
dc.identifier.issn	1095-4244	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/17821
dc.subject	noise	en
dc.subject	propagation	en
dc.subject	wind turbine	en
dc.subject	wind park	en
dc.subject	ray theory	en
dc.subject	complex terrain	en
dc.subject.classification	Energy & Fuels	en
dc.subject.classification	Engineering, Mechanical	en
dc.subject.other	OUTDOOR SOUND-PROPAGATION	en
dc.subject.other	PROFILE	en
dc.subject.other	BOUNDARY	en
dc.subject.other	LAYER	en
dc.title	Application of a ray theory model to the prediction of noise emissions from isolated wind turbines and wind parks	en
heal.type	journalArticle	en
heal.identifier.primary	10.1002/we.211	en
heal.identifier.secondary	http://dx.doi.org/10.1002/we.211	en
heal.language	English	en
heal.publicationDate	2007	en
heal.abstract	Various propagation models have been developed to estimate the level of noise near residential areas. Predictions and measurements have proven that proper modelling of the propagation medium is of particular importance. In the present work, calculations are performed using a ray theory methodology. The ray trajectory, and transport equations are derived from the linear acoustics equations for a moving medium in three dimensions. Ground and atmospheric absorption, wave refraction and diffraction and atmospheric turbulence are taken into account by introducing appropriate coefficients in the equations. In the case of a wind turbine (WIT) it is assumed that noise is produced by a point source located at the rotor centre. Given the sound power spectrum, the noise spectrum at the receiver is obtained by solving the axisymmetric propagation problem. The procedure consists of (a) finding the eigenrays, (b) calculating the energy losses along the eigenrays and (c) synthesizing the sound pressure level (SPL) by superposing the contributions of the eigenrays. in the case of a wind park the total SPL is calculated by superposing the contributions of all W/Ts. Application is made to five cases of isolated W/Ts in terrains of varying complexity. In flat or even smooth terrain the predictions agree well with the measurements. In complex terrain the predictions can be considered satisfactory, taking into account the assumption of constant wind velocity profile. Application to a wind park shows clearly the influence of the terrain on the wind velocity and consequently on the SPL. Copyright (C) 2006 John Wiley & Sons, Ltd.	en
heal.publisher	JOHN WILEY & SONS LTD	en
heal.journalName	WIND ENERGY	en
dc.identifier.doi	10.1002/we.211	en
dc.identifier.isi	ISI:000245481200001	en
dc.identifier.volume	10	en
dc.identifier.issue	2	en
dc.identifier.spage	103	en
dc.identifier.epage	119	en