非定常かく乱に対するディフューザ内はく離流れの応答
1997 年 63 巻 605 号 p. 54-61
詳細
1997 年 63 巻 605 号 p. 54-61
The response of a separating flow in a two-dimensional diffuser to an unsteady disturbance is investigated. The disturbance is generated by the turbulent wake of a circular cylinder moving in front of the entrance of the diffuser. Thus the disturbance makes an angle to the main-flow direction. The pressure recovery coefficient, time-mean velocity distribution and phase-averaged velocity distribution are obtained for several disturbances with different frequencies and different angles. Reynolds number based on the velocity of the main flow at the inlet of the diffuser and its height is 5.2 x 104. The pressure recovery coefficient is found to be modified by the disturbance, depending on the frequency of the disturbance. The local deceleration and acceleration are observed near the wall of the inlet of the diffuser due to the disturbance. Thus the disturbance generated by the wake acts as an oscillator to induce a velocity fluctuation at a specific area.
