Wind Farm Noise

Professor Colin Hansen has been consulting, researching and teaching in the field of noise and vibration for 40 years. He has authored or co-authored eleven books, edited two books, and contributed seven chapters to various other books. His current research is focused on the generation, assessment and control of wind farm noise, on which he has been working since 2010 and for which he has been funded by the Australian Research Council. He is an Honorary Fellow and past-president of the International Institute of Acoustics and Vibration, a Fellow of the Australian Acoustical Society and a Fellow of Engineers Australia. He was awarded the 2009 Rayleigh Medal by the British institute of Acoustics for outstanding contributions to acoustics, the 2013 A.G.M. Michell medal by Engineers Australia for outstanding service to the discipline of Mechanical Engineering and the 2014 Rossing Prize in Acoustics Education by the Acoustical Society of America.AssociateProfessor Doolan has an Honours Degree in Mechanical Engineering and a PhD in Aerospace Engineering from the University of Queensland.  He has over 20 years experience in research and development, teaching and consulting, with over 150 technical publications.  His research interests focus upon compressible flow, which includes the area of aeroacoustics - the science of how fluid flow creates sound - with the aim to control noise from modern technologies such as aircraft, wind turbines and submarines.  Associate Professor Doolan has been involved for many years in the understanding and control of wind turbine noise, with funding from the Australian Research Council to perform aeroacoustic testing of scaled turbines in wind tunnels.Dr Kristy Hansen completed an Honours Degree in Mechanical Engineering and a PhD in Aerodynamics/Fluid Mechanics at the University of Adelaide. She spent 3 years working on an Australian Research Council funded grant investigating the impact of wind farm noise on rural communities. This work involved collection of an extensive data set which resulted from simultaneous measurements of noise, vibration and meteorological data at rural locations near different wind farms. Results from the analysis of these data have been presented in a number of peer-reviewed journals and conference papers. She is continuing her research on wind farm noise as part of her current employment at Flinders University.

• Wiley Series in Acoustics, Noise and Vibration xvPreface xvii1 Wind Energy and Noise 11.1 Introduction 11.2 Development of the Wind Energy Industry 21.3 History of Wind Turbine Noise Studies 131.4 Current Wind Farm Noise Guidelines and Assessment Procedures 181.5 Wind Farm Noise Standards 291.6 Regulations 321.7 Inquiries and Government Investigations 431.8 Current Consensus on Wind Farm Noise 52References 522 Fundamentals of Acoustics and Frequency Analysis 572.1 Introduction 572.2 Basic Acoustics Concepts 572.3 Basic Frequency Analysis 792.4 Advanced Frequency Analysis 882.5 Summary 117References 1173 Noise Generation 1193.1 Introduction 1193.2 Aeroacoustics 1223.3 Aerodynamic Noise Generation on Wind Turbines 1283.4 Aero-elasticity and Noise 1483.5 Other Noise Sources 1493.6 Summary and Outlook 151References 1524 Wind Turbine Sound Power Estimation 1574.1 Introduction 1574.2 Aerodynamic Noise Prediction 1574.3 Simple Models 1584.4 Semi-empirical Methods (Class II Models) 1594.5 Computational Methods (Class III Models) 1684.6 Estimations of Sound Power From Measurements 1694.7 Summary 177References 1775 Propagation of Noise and Vibration 1805.1 Introduction 1805.2 Principles Underpinning Noise Propagation Modelling 1825.3 Simplest Noise Propagation Models 2125.4 Danish Low-frequency Propagation Model 2135.5 Concawe (1981) 2145.6 ISO9613-2 (1996) Noise Propagation Model 2235.7 NMPB-2008 Noise Propagation Model 2315.8 Nord2000 Noise Propagation Model 2425.9 Harmonoise (2002) Noise Propagation Engineering Model 2605.10 Required Input Data for the Various Propagation Models 269\5.11 Offshore Wind Farm Propagation Models 2725.12 Propagation Model Prediction Uncertainty 2725.13 Outside versus Inside Noise at Residences 2765.14 Vibration Propagation 2805.15 Summary 283References 2856 Measurement 2896.1 Introduction 2896.2 Measurement of Environmental Noise Near Wind Farms 2906.3 Vibration 3936.4 Wind, Wind Shear and Turbulence 3956.5 Reporting on Noise, Vibration and Meteorological Conditions 4056.6 Wind Tunnel Testing 4086.7 Conclusions 425References 4257 Effects of Wind Farm Noise and Vibration on People 4367.1 Introduction 4367.2 Annoyance and Adverse Health Effects 4417.3 Hearing Mechanism 4557.4 Reproduction of Wind Farm Noise for Adverse Effects Studies 4657.5 Vibration Effects 4677.6 Nocebo Effect 4677.7 Summary and Conclusion 468References 4708 Wind Farm Noise Control 4768.1 Introduction 4768.2 Noise Control by Turbine Design Modification 4778.3 Optimisation of Turbine Layout 4878.4 Options for Noise Control at the Residences 4888.5 Administrative Controls 4928.6 Summary 493References 4939 Recommendations for Future Research 4969.1 Introduction 4969.2 Further Investigation of the Effects of Wind Farm Noise on People 4979.3 Improvements to Regulations and Guidelines 4999.4 Propagation Model Improvements 5049.5 Identification and Amelioration of the Problem Noise Sources on Wind Turbines 5049.6 Reducing Low-frequency Noise Levels in Residences 506References 506A Basic Mathematics 507A.1 Introduction 507A.2 Logarithms 507A.3 Complex Numbers 508A.4 Exponential Function 508B The BPM model 509B.1 Boundary-layer Parameters 509B.2 Turbulent Trailing-edge Noise Model 511B.3 Blunt Trailing-edge Noise Model 513Reference 515C Ground Reflection coefficient calculations 516C.1 Introduction 516C.2 Flow Resistivity 517C.3 Characteristic Impedance 518C.4 Plane-wave Reflection Coefficient 520C.5 Spherical-wave Reflection Coefficient 521C.6 Incoherent Reflection Coefficient 524References 525D Calculation of Ray Path Distances and Propagation Times for the Nord2000 Model 526D.1 Introduction 526D.2 Equivalent Linear Atmospheric Vertical Sound-speed Profile 527D.3 Calculation of Ray Path Lengths and Propagation Times 529References 532E Calculation of Terrain Parameters for the Nord2000 Sound Propagation Model 534E.1 Introduction 534E.2 Terrain Effects 534E.3 Approximating Terrain Profiles by Straight-line Segments 539E.4 Calculation of the Excess Attenuation due to the Ground Effect for Relatively Flat Terrain with no Diffraction Edges 540E.5 Calculation of the Excess Attenuation due to the Ground Effect for Relatively Flat Terrain with a Variable Impedance Surface and no Diffraction Edges 541E.6 Calculation of the Excess Attenuation due to the Ground Effect for Valley-shaped Terrain 543E.7 Identification of the Two Most Efficient Diffraction Edges 544E.8 Calculation of the Sound Pressure at the Receiver for each Diffracted Path in Hilly Terrain 547E.9 Calculation of the Combined Ground and Barrier Excess-attenuation Effects 556References 563F Calculation of Fresnel Zone Sizes and Weights 564F.1 Introduction 564F.2 Fresnel Zone for Reflection from Flat Ground 564F.3 Fresnel Weights for Reflection from a Concave or Transition Ground Segment 567F.4 Fresnel Weights for Reflection from a Convex Ground Segment 570Reference 571G Calculation of Diffraction and Ground Effects for the Harmonoise Model 572G.1 Introduction 572G.2 diffraction Effect, ΔL d 574G.3 Ground Effect 577G.4 Fresnel Zone for Reflection from a Ground Segment 584References 587H Active Noise-control System Algorithms 588H.1 Introduction 588H.2 Single-input, Single-output (SISO) Weight Update Algorithm 588H.3 Multiple-input, Multiple-output Weight Update Algorithm 590References 592Index 593