A new measurement system of wall pressure fluctuations on a rotating machinery, composed of
digital recording device, was developed and evaluated. The small-sized digital recording device was
attached on the rotating machinery and then was detached for data reduction. In order to obtain the
system transfer function of the digital recording system, a dynamic calibration was performed utilizing
the signal from a 1/8 inch B&K microphone as input. The time history of the unsteady pressure was
then reconstructed from the output of the sensor by using this transfer function. The reconstructed
pressure signals showed good agreement with the reference signal in both temporal and spectral sense.
This sensor was then used to measure the wall pressure fluctuations on a rotating blade. An array of
microphones were installed on the blade in the circumferential and radial directions. Various statistical
moments were obtained from the measurement data set. Comparison of these quantities with the
existing studies demonstrated satisfactory agreement. These tests give credence to the relevance and
reliability of this device for applications in more complicated turbulent rotating machineries.