Measuring Wind Turbine Coherent Infrasound Seminar
- Time:
- 16:00
- Date:
- 8 March 2016
- Venue:
- Building 13 Room 3017 University of Southampton
For more information regarding this seminar, please email isvr@soton.ac.uk .
Event details
To extract the optimum coherent infrasound signal from a wind turbine whose rotation is not precisely periodic, we use an optical telescope fitted with a photodetector to obtain reference blade passage periods, recording these together with the microphone infrasound signal.
Signal processing of the quasi-periodic microphone signal is then used to obtain periodic data, which are analyzed by an appropriate length DFT to extract optimum values for the fundamental and harmonics of the coherent signal. The general procedure is similar to order domain analysis for rotating machines and is thoroughly explained and illustrated with measurements and analysis from a number of different wind farms. If several turbines are measured by a single microphone with blade passage periods obtained from several separate reference tracks, it may be possible to retrieve separate useful coherent signals from multiple turbines by appropriate processing.
Speaker information
John Vanderkooy, University of Waterloo. John Vanderkooy has presented many AES papers over the years on a range of topics, many with his colleague Stanley Lipshitz, both founding members of the Audio Research Group at the University of Waterloo, Ontario, Canada. Since retirement, John and his wife Judy have spent winters in the UK at the Steyning Research Centre of Bowers and Wilkins. He continues both the supervision of graduate students and his audio research at the University of Waterloo. Some recent work includes the non-linear acoustics of the trumpet, and the measurement of infrasound inside cars and from wind turbines.