Semi-empirical framework for predicting the noise from wind-turbine blades with serrated trailing edges

This work proposes a semi-empirical framework to predict the noise of wind turbines with serrated trailing edge blades. The framework is employed for studying the reduction of the noise of the SWT 2.3-93 benchmark wind turbine. The framework is verified against field acoustic measurements of the real wind-turbine model and of noise reduction...

Aeroacoustic Benchmarking of Trailing-Edge Noise from NACA 63₃ –018 Airfoil with Trailing-Edge Serrations

Experimental results on trailing-edge (TE) noise from a NACA 63₃ –018 airfoil are presented for a chord-based Reynolds number Re_c range between 2 × 10⁵ and 3 × 10⁶. Far-field TE noise from the baseline airfoil with a straight TE and TE serrations is measured with varying Re_c, angle of...

A parametric study of serration design for trailing–edge broadband noise reduction

This work discusses the physics of noise reduction achieved from serrated trailing–edges and its impact by the serration design. An experimental campaign is carried out with a benchmark 2D model based on a NACA 63₃–018 airfoil. Different trailing-edge serrations are tested under several flow speeds and angles of attack conditions...

Benchmarking of the NACA 633-018 Trailing-Edge Noise in a Broad Reynolds Number Range as Part of the IEA Task 39

An experimental aero-acoustic characterisation of the NACA 63 ₃-018 airfoil is presented in this study, featuring trailing-edge noise emissions with and without serrations. Measurements have been carried out for a chord-based Reynolds number range between 0.18 × 10 ⁶ and 4.8 × 10 ⁶ . Two airfoil models with...

A physics-based description and modelling of the wall-pressure fluctuations on a serrated trailing edge

A physical description of the flow mechanisms that govern the distribution of the wall-pressure fluctuations over the surface of a serrated trailing edge is proposed. Three main mechanisms that define the variation of turbulent pressure fluctuations across the serrated edge are discussed and semi-empirical models are formulated accordingly....

Aeroacoustics of sawtooth trailing-edge serrations under aerodynamic loading

The impact of aerodynamic loading on a serrated trailing edge is studied experimentally. Aerodynamic and acoustic measurements are conducted on a sawtooth-shaped trailing edge, retrofitted to a flat plate featuring a trailing-edge flap, and placed at incidence to the free-stream flow. The turbulent flow across the trailing edge is inspected...

Wall pressure fluctuations over a serrated trailing edge at different angles of attack

iew Video Presentation: https://doi-org.tudelft.idm.oclc.org/10.2514/6.2021-2179.vid<br/><br/>The unsteady surface pressure fluctuations over trailing-edge serrations retrofitted to the benchmark NACA 633-018 profile are experimentally measured. Miniaturized unsteady pressure transducers installed on the serration surface are used to describe...

Aeroacoustic design and characterization of the 3D-printed, open-jet, anechoic wind tunnel of Delft University of Technology

The newly refurbished vertical tunnel (V-tunnel) at Delft University of Technology has been redesigned as a state-of-the-art facility for research in aeroacoustics (A-tunnel), as well as fundamental studies in laminar-turbulent transition and flow control. This manuscript focuses on the design and refurbishment aspects of the facility,...

Pressure fluctuations from large-scale PIV over a serrated trailing edge

Abstract: Measurements of distributed surface pressure fluctuations over trailing-edge serrations at a Reynolds number Re _θ = 4900 are performed with time-resolved 3D particle imaging velocimetry using helium filled soap bubbles as flow tracers. The sparse velocity vector field obtained with Lagrangian particle tracking is densely...