Flow topology and acoustic emissions of trailing edge serrations at incidence

Arce Leon, C.A.; Ragni, D.; Pröbsting, S.; Scarano, F.; Madsen, Jesper

doi:10.1007/s00348-016-2181-1

Flow topology and acoustic emissions of trailing edge serrations at incidence

Title

Flow topology and acoustic emissions of trailing edge serrations at incidence

Author

Arce Leon, C.A. (TU Delft Aerodynamics)
Ragni, D. (TU Delft Wind Energy)
Pröbsting, S. (TU Delft Wind Energy)
Scarano, F. (TU Delft Flow Physics and Technology)
Madsen, Jesper (Aerodynamics and Acoustics Group)

Department

Flow Physics and Technology

Date

2016

Abstract

The flow past a NACA 0018 airfoil with sawtooth trailing edge serrations has been investigated using stereoscopic particle image velocimetry (PIV). The serration flap angle and airfoil incidence are varied in order to study the effect of secondary flow establishing between the suction and pressure sides of the serrations. The flow topology around the serrations is inferred from the analysis of time-averaged streamlines close to the airfoil surface and from the wall-normal flow velocity in between serrations. Additional PIV measurements with a plane in cross-flow highlight the formation of streamwise vortex pairs. The flow behavior is further characterized in terms of its turbulence statistics. Noise emissions are measured with an acoustic phased array in combination with beamforming. The serrations are found to be effective in reducing noise, and their application is studied for different degrees of airfoil incidence and serration flap angle.

Subject

Particle image velocimetry
Aeroacoustics
Serrated trailing
edges

To reference this document use:

http://resolver.tudelft.nl/uuid:206cddce-b82a-4f76-a389-e56657110b3b

DOI

https://doi.org/10.1007/s00348-016-2181-1

ISSN

0723-4864

Source

Experiments in Fluids: experimental methods and their applications to fluid flow, 57

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