Influence of the turbulent boundary layer pressure fluctuation on the sound intensity measurement in a mean flow

The influence of turbulent boundary layer pressure fluctuation on the sound intensity measurement in a flow is a subject of practical concern, because the sound intensity probe is generally exposed to the airflow and is sensed the turbulent boundary layer (TBL) pressure fluctuation which may even overwhelm the true source pressure in some cases.

In this paper, the model of the sound intensity caused by the TBL pressure fluctuation is described firstly. Based upon the developed model, the sound intensity caused by the TBL pressure fluctuation is calculated using the available models of the wave-vector frequency spectra of the TBL pressure fluctuation.

In order to validate the model and the numerical results, a serious of measurements were carried out. It is shown that the calculated results of the TBL pressure fluctuation agree fairly well with the measured results which are corrected with the estimated spatial response function of the microphone.

Also, the characteristics of the measured sound intensity are consistent with that of the calculated sound intensity.