オリフィス下流における流れ加速腐食機構に関する数値的研究
Numerical research on flow accelerated corrosion mechanism behind the orifice-Numerical simulation close to the wall
著者:
七條 慎太郎 Shintaro SHICHIJO 古谷 真伍 Shingo HURUYA 近藤 昌也 Masaya KONDO 辻 義之 Yoshiyuki TSUJI
発刊日:
公開日:
and turbulence kinetic energyflow accelerated corrosionKey wordsLESOrifice
概要
Abstract The accident to which the secondary system piping of the Mihama Power Station Unit-3 was damaged in August, 2004 happened. This is due to thinning of the pipe, and it is thought to be flow accelerated corrosion mechanism (FAC). The turbulence kinetic energy is considered as one of the flow factors in FAC. This is because the location where the amount of thinning is large and the parts where the turbulence kinetic energy is high are corresponding comparatively well. However, the causal relation between both parts is no t clarified enough and the research advances now. Then, the flow field in the orifice downstream is calculated by the numerical simulation. The numerical simulation of LES in flow field (Re=25000) in the orifice downstream is performed. The distribution of the turbu lence kinetic energy indicates the maximum value at the position that depended on s of the open area ratio of the orifice. In the rough side shape, the position in which the turbulence kinetic energy shows the maximum changes depending on the distance from the wall.
