Connections between Organ Pipe Noise and Shannon Entropy of the Airflow: Preliminary Results

Possible connections between statistical airflow parameters and amount of noise in the flue organ pipe signal was investigated by means of particle image velocimetry (PIV). Differences between free-run and phase-locked PIV synchronization techniques were discussed. Results show a strong evidence that there is a region in which there is a linear relation between the airflow Shannon entropy H obtained by biorthogonal decomposition of the PIV data and harmonics-to-noise ratio HNR expressed in dB. A preliminary linear relation was received: HNR ≈ –125 H + 77.9.