The structure of a turbulent boundary layer and its relation to the wall pressure fluctuation

The wall pressure fluctuation and its relation to the turbulence structure of a boundary layer have been investigated experimentally. The effect of common mode noise of the pressure which are known to be caused by the vibration of the wall and the fan were carefully removed and various correlation analyses together with ensemble averagings which refer either to the bulge or the burst were carried out. The correlation measurements show that the wall pressure fluctuation is very much related to the flow fluctuation whole through and beyond the boundary layer. The ensemble average of the pressure fluctuation reveals that the bulge and the burst are both responsible to the wall pressure fluctuation, although the latter is more direct and effective. Various correlations suggest a strong causality between the bulge and the burst.