Aero-acoustics noise assessment for Wind-Lens turbine

This paper introduces an aero-acoustic computational study that investigates the noise caused by one of the most promising wind energy conversion concepts, namely the "Wind-Lens" technology. The hybrid method - where the flow field and acoustic field are solved separately, was deemed to be an appropriate tool to compute this study. The need to investigate this phenomenon increased gradually, since the feasibility of utilizing Wind-Lens turbine within densely populated cities and urban areas depends largely on their noise generation. Ffowcs Williams-Hawkings (FW-H) equation and its integral solution are used to predict the noise radiating to the farfield. CFD Simulations of transient three-dimensional flow field using (URANS) unsteady Reynolds-averaged Navier-Stokes equations are computed to acquire the acoustic sources location and sound intensity. Then, the noise propagates from the before-mentioned sources to pre-defined virtual microphones positioned in different locations. ANSYS-FLUENT is used to calculate the flow field on and around such turbines which is required for the FW-H code. Some effective parameters are investigated such as Wind-Lens shape, brim height and tip speed ratio. Comparison of the noise emitted from the bare wind turbine and different types of Wind-Lens turbine reveals that, the Wind-Lens generates higher noise intensity.

[1]  Yuji Ohya,et al.  A Shrouded Wind Turbine Generating High Output Power with Wind-lens Technology , 2010 .

[2]  M. H. Mohamed Aero-acoustics noise evaluation of H-rotor Darrieus wind turbines , 2014 .

[3]  Thomas F. Brooks,et al.  Airfoil self-noise and prediction , 1989 .

[4]  Masoud Ghasemian,et al.  Aerodynamic noise prediction of a Horizontal Axis Wind Turbine using Improved Delayed Detached Eddy Simulation and acoustic analogy , 2015 .

[5]  F. Farassat,et al.  Introduction to Generalized Functions With Applications in Aerodynamics and Aeroacoustics , 1994 .

[6]  Kun Luo,et al.  Large-eddy simulation and wind-tunnel measurement of aerodynamics and aeroacoustics of a horizontal-axis wind turbine , 2015 .

[7]  S Brentner Kenneth,et al.  Modeling Aerodynamically Generated Sound: Recent Advances in Rotor Noise Prediction , 2000 .

[8]  F. Farassat,et al.  An Analytical Comparison of the Acoustic Analogy and Kirchhoff Formulation for Moving Surfaces , 1997 .

[9]  W. Schröder,et al.  Acoustic perturbation equations based on flow decomposition via source filtering , 2003 .

[10]  F. Farassat,et al.  Modeling aerodynamically generated sound of helicopter rotors , 2003 .

[11]  Eric J. Simley,et al.  Development of an acoustic array for wind turbine aeroacoustic noise analysis , 2010 .

[12]  M. H. Mohamed Reduction of the generated aero-acoustics noise of a vertical axis wind turbine using CFD (Computational Fluid Dynamics) techniques , 2016 .

[13]  Pieter Sijtsma,et al.  Nationaal Lucht-en Ruimtevaartlaboratorium National Aerospace Laboratory NLR NLR-TP-2007-798 Location and quantification of noise sources on a wind turbine , 2008 .

[14]  Pierre Sagaut,et al.  Large-eddy simulation for acoustics , 2007 .

[15]  Thierry Maeder,et al.  Reduction of Wind Turbine Noise using Optimized Airfoils and Trailing-Edge Serrations , 2008 .

[16]  Gianfranco Guidati,et al.  Wind Turbine Noise , 1996 .

[17]  Lyle N. Long,et al.  AN AEROACOUSTIC ANALYSIS OF WIND TURBINES , 2004 .

[18]  Wenjing Ye,et al.  Theoretical and Numerical Studies of Noncontinuum Gas-Phase Heat Conduction in Micro/Nano Devices , 2010 .

[19]  Stefan Oerlemans,et al.  Experimental characterization of turbulent inflow noise on a full-scale wind turbine , 2016 .

[20]  N. Curle The influence of solid boundaries upon aerodynamic sound , 1955, Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences.

[21]  Kun Xu,et al.  Multiple temperature kinetic model and its applications to micro-scale gas flows , 2012 .

[22]  Esteban Ferrer,et al.  Investigation of computational aeroacoustic tools for noise predictions of wind turbine aerofoils , 2007 .

[23]  M. Zangeneh,et al.  Numerical prediction of wind turbine noise , 2011 .

[24]  裕二 大屋,et al.  A Simple Theory of Wind Turibine with Brimmed Diffuser , 2002 .

[25]  Takanori Uchida,et al.  Numerical Studies of Flow around a Wind Turbine Equipped with a Flanged-Diffuser Shroud Using an Actuator-Disk Model , 2012 .

[26]  M. Lighthill On sound generated aerodynamically II. Turbulence as a source of sound , 1954, Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences.

[27]  M. Lighthill On sound generated aerodynamically I. General theory , 1952, Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences.

[28]  D. W. Robinson,et al.  A re-determination of the equal-loudness relations for pure tones , 1956 .

[29]  N. D. Kelley,et al.  Acoustic noise associated with the MOD-1 wind turbine: its source, impact, and control , 1985 .

[30]  D. L. Hawkings,et al.  Sound generation by turbulence and surfaces in arbitrary motion , 1969, Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences.

[31]  Jens Nørkær Sørensen,et al.  AERO-ACOUSTIC COMPUTATIONS OF WIND TURBINES , 2002 .

[32]  S. Pope BOOK REVIEW: Turbulent Flows , 2001 .

[33]  John Cater,et al.  Aeroacoustic noise prediction for wind turbines using Large Eddy Simulation , 2015 .