Study on thermal striping phenomena in triple-parallel jet; Investigation on non-stationary heat transfer characteristics based on numerical simulation

平行三噴流によるサーマルストライピングに関する研究; 数値解析による非定常熱伝達挙動に関する評価

木村 暢之; 上出 英樹 ; Emonot, P.*; 長澤 一嘉*

Kimura, Nobuyuki; Kamide, Hideki; Emonot, P.*; Nagasawa, Kazuyoshi*

温度の異なる流体の混合により発生する温度変動に起因する高サイクル熱疲労現象を評価するために、平行三噴流水流動試験体系を対象とした流体構造連成解析を実施した。これにより、構造材表面での温度変動強度の減衰を定量的に明らかにするとともに、温度変動の伝達挙動の評価を行った。

A quantitative evaluation on thermal striping, in which temperature fluctuation due to convective mixing between hot and cold fluids causes thermal fatigue in structural components, is of importance for reactor safety. In this study, a water experiment of parallel triple jets configuration was performed in order to evaluate temperature fluctuation characteristics in fluid, transfer characteristics of temperature fluctuation from fluid to structure. The power spectrum densities of temperature fluctuation, furthermore, were in good agreements between the experiment and calculation. The calculated results showed that the heat transfer coefficient obtained from the experiment was appropriate and proper. The decay due to the heat transfer at the wall surface was dominant for the decay of temperature fluctuation at the neighborhood of the wall.