Printed book · Report
High frequency microphone measurements for transition detection on airfoils. Risø C2-18 appendix report
Aeroelastic Design, Wind Energy Division, Risø National Laboratory for Sustainable Energy, Technical University of Denmark1
Wind Energy Division, Risø National Laboratory for Sustainable Energy, Technical University of Denmark2
Risø National Laboratory for Sustainable Energy, Technical University of Denmark3
Time series of pressure fluctuations has been obtained using high frequency microphones distributed over the surface of airfoils undergoing wind tunnel tests in the LM Windtunnel, owned by ’LM Glasfiber’, Denmark. The present report describes the dataanalysis, with special attention given to transition detection.
It is argued that the transition point can be detected by observing the increase in the mean of the Fourier spectre and that thismethod is very stable froma numerical point of view. Other important issues are also discussed, e.g. the variation of pressure standard deviations (sound pressure) and Tollmien-Schlichting frequencies.
The tests were made at Reynolds and Mach numbers corresponding to the operating conditions of a typical horizontal axis wind turbine (HAWT). The Risø B1-18, Risø C2-18 and NACA0015 profiles were tested and the measured transition points are reported.
| Language: | English |
|---|---|
| Publisher: | Danmarks Tekniske Universitet, Risø Nationallaboratoriet for Bæredygtig Energi |
| Year: | 2008 |
| Pages: | 179 s. |
| Series: | Denmark. Forskningscenter Risoe. Risoe-r |
| ISBN: | 8755036767 and 9788755036765 |
| ISSN: | 01062840 |
| Types: | Printed book and Report |
