A study on the prediction of aerofoil trailing-edge noise for wind-turbine applications

This paper presents a comparative study between the so-called BPM and TNO models for the prediction of aerofoil trailing-edge noise with particular emphasis on wind-turbine applications (the BPM model is named after Brooks, Pope and Marcolini who first proposed the model, and the TNO model is named after the TNO institute of Applied Physics where it was first proposed). In this work, two enhanced versions of the BPM model are proposed, and their performances are compared against two recent anisotropic TNO models that require more detailed boundary-layer information than the BPM-based models. The two current enhanced models are denoted as BPMM-PVII and BPMM-BLk?, where the former uses a panel method with viscous-inviscid interaction implemented (PVII) for boundary-layer calculations, the latter estimates the boundary-layer (BL) properties using a two-dimensional k-? turbulence model (k?), and BPMM stands for BPM-Modified. By comparing the predicted sound spectra with existing measurement data for seven different aerofoils tested in the current study, it is shown that the BPMM-PVII model exhibits superior results to those by the other models for most cases despite the simplicity without considering anisotropy. The BPMM-PVII model is then combined with Prandtl's nonlinear lifting-line theory to calculate and investigate three-dimensional rotor noise characteristics of an NREL UAE Phase-VI wind turbine (NREL UAE stand for the National Renewable Energy Laboratory Unsteady Aerodynamic Experiment). It is demonstrated that the current approach may provide an efficient solution for the prediction of rotor aerodynamics and noise facilitating industrial design and development for low-noise wind turbines