抄録
A Rapidly-Pulsating flow was experimentally studied in a straight circular pipe. The flow was generated by a computer-controlled valve operated at the interval of 0.2 second. The distribution of axial velocity was measured using I-type hot-wire probe under three condition of the valve stroke such as small, medium and large amplitude. In case of medium amplitude, the velocity distribution was delayed due to the effect of oscillatory boundary layer in the downstream near Z=5d. In case of large amplitude, the similar phenomenon was observed in the inlet entrance during the accelerating phase and the velocity distribution was largely distorted in the central portion of pipe near Z=5d.
