Abstract
Although it is a known fact that there exist coherent motions in a turbulent boundary layer ; the slowly rotating flow in the outer region (turbulent bulge) and the burst in the inner region, the relations between them are not clear yet.
The present experiment was carried out in order to find the dependency between these coherent motions through the simultaneous measurements of the wall pressure and the velocity field because the pressure fluctuations are induced by flow fluctuations throughout the boundery layer. The conclusions are ; (i) the wall pressure fluctuations are composed of low and high frequency components which are responsible to the bulge and the burst respectedly, and (ii) the burst appears in a certain (acceleration) phase in the passage of the bulge, suggesting the close relationship between them.
