Aeroacoustic Wind Tunnel Tests

Aero-acoustic wind tunnel tests


This project will develop and validate the aero-acoustic measurement setup in the Poul la Cour Wind Tunnel.

Background

The Danish National Wind Tunnel, also called the “Poul la Cour Tunnel”, is being established at DTU Risø Campus and will be dedicated for wind energy use. The tunnel is designed for aerodynamic and aero‐acoustic tests of wind turbine blade sections. It will be possible to test blade sections at flow speeds of up to 105 m/s - equivalent to the typical flow speed near the blade tip of a large wind turbine. The test section is surrounded by a large anechoic chamber to enable aero‐acoustic measurements. The aerodynamic noise emitted from the blade will pass through porous Kevlar® walls of the test section and measured with a microphone array outside the flow. The microphone array can filter out unwanted background noise in the tunnel and focus the analysis on specific parts of the blade section to give a precise estimation of the noise emission.

Objectives

Measurements in the “Poul la Cour tunnel” can simultaneous map the aerodynamic and acoustic performance of a wind turbine blade section including the noise sources and the dependencies on turbulence intensities.

This project will:

  • Implement and develop signal processing techniques for microphone array measurements specific to the conditions in the wind tunnel. It will account for background noise, losses introduced by the Kevlar walls and make corrections related to the aerodynamic properties of the flow.
  • Setup and validate aero-acoustic measurement techniques.
  • Develop algorithms for the quantification of trailing edge noise including uncertainty estimates.
  • Determine conditions for simultaneous measurement of aerodynamic and acoustic properties of wing sections.

The study requires development of theoretical and experimental methods within aerodynamics and acoustics and will result in a measurement setup that is capable of quantifying aerodynamic noise from a blade section.

Perspectives

The aim is to provide precise aero-acoustic measurements to help researchers and companies evaluate prototypes of future blade designs as well as noise reducing mechanisms.

Contact

Oliver Ackermann Lylloff
PhD student
DTU Wind Energy