管内オリフィス下流の変動成分に関する実験的研究
1992 年 58 巻 556 号 p. 3547-3551
詳細
1992 年 58 巻 556 号 p. 3547-3551
The fluctuating velocity and pressure downstream of a pipe orifice were experimentally investigated at Red≒1.7×105. For the standard sharp-edged orifices, 0.4∼0.8 in diameter ratio, the inner velocity fluctuations and the wall pressure fluctuations were measured by means of hot wire probes and pressure transducers. It is clear that the turbulence intensity on the orifice jet periphery is about twice as high as that in the flow near the wall surface at a short distance from the orifice. More high-frequency components are included in the spectrum of the fluctuating wall pressures in the downstream reverse-flow region than in the irreverse-flow region further downstream. The reverse-flow region was detected by the flow direction detector and was visualized by a spark tracing method.
