デﾕアルエルボにおける複雑流動構造の解明
Clarification of complex flow structure in dual elbow
著者:
矢内 宏樹 Hiroki YANAI 吉田 和弘 Kazuhiro YOSHIDA 結城 和久 Kazuhisa YUKI 戸田 三朗 Saburo TODA 河上 晃 Akira KAWAKAMI 秋葉 真司 Shinji AKIBA
発刊日:
公開日:
complex flowFACmulti-elbows-shaped dual elbow
概要
Relatively a large number of pipe failures in a nuclear power plant occur in a multi-component region such as the bends, the orifices and so on. Especially, it has been reported that FAC (Flow Accelerated Corrosion) frequently occurs in a multi-elbow. In this study, therefore, a complex flow structure in a s-shaped dual elbow is observed by using a PIV system to clarify the flow structure. The diameter of the elbow D is 56mm and the curvature radius rate y (=R/D,where Re is a curvature radius) is 1.5. A f low field obtained by the PIV system is analyzed to determine the velocity distribution and the fluctuation characteristics at Reynolds number of 4.3 X 104. The experimental results showed that peak velocity in 1st elbow is about 1.6 times of average flow velocity at the entrance of 1st elbow while, the peak velocity in 2nd elbow velocity is about 2 times of average flow velocity at the entrance of 1st elbow. This result indicates that the FAC could occur more easily at the 2nd elbow than at the 1st elbow.
