Field Trip to the Wind turbine on October 26, 2005

 

·        Sound sources at the wind turbine

·        Layout of the observation grid:

Click on the red letters in order to hear a recording of the sound at this point. The actual sound from the turbine is weak compared to noises from wind –microphone interactions.

We were not able to access point H, only approximately, and points A and B were in a freshly plowed field.

 

·        Data:

Students rated the loudness of the sound for the designated grid points on a scale of 1 through 10.

Two student groups were equipped with decibel meters and recorded the readings.

All data have been normalized to a scale of 1 through 10, and are summarized below.

The excel data file can be found here.

 

·        Points A through H: Loudness along the axis of the turbine from upwind to downwind

·        Points I through L: Loudness across a line perpendicular to the axis of the turbine:

The blades were moving down ward close to J, and upward close to K

·        Noteworthy features:

-         There is a nice and clear correlation between the average subjective student rating of the loudness, and the actually measured sound level.

-         The sound is of highest intensity behind the wind turbine.

-         The data in front of the turbine (A-C) are skewed due the presence of the plowed field, which only some students chose to concquer.

-         The point directly under the wind turbine is actually one of least noise from the rotating blades.

-         The sound field to the left and right of the wind turbine is asymmetric.