Application of U-RANS to elbow pipe flow with small curvature radius under high Reynolds number condition

高レイノルズ数条件下におけるショートエルボ流れへの非定常RANS解析の適用

田中 正暁  ; 大島 宏之; 山野 秀将   ; 相澤 康介 ; 藤崎 竜也*

Tanaka, Masaaki; Ohshima, Hiroyuki; Yamano, Hidemasa; Aizawa, Kosuke; Fujisaki, Tatsuya*

ナトリウム冷却高速炉の大口径エルボ配管部における流動解析評価手法の構築を目的とし、実機ホットレグ配管を1/3縮尺とした既往水流動試験を対象にCFDコードのレイノルズ応力モデル(RSM)を用いた非定常解析を行い、適用可能な解析オプションの検討と解析結果の妥当性を確認した。さらに、レイノルズ数3.7E+6の条件における、ショートエルボで発生する非定常渦構造と圧力変動との関係について知見を得た。

In this study, applicability of the Unsteady Reynolds Averaged Navier-Stokes equations (U-RANS) approach with the Reynolds Stress Model (RSM) to the flow through the short-elbow under high Reynolds number condition was examined through an analysis of 1/3 scaled water experiment (mean velocity is 9.2 m/s and Re number is 3.7E+6) simulates the hot-leg piping of the JSFR. Applicable numerical options in the U-RANS approach were identified through parametric study for time integration schemes and discretization schemes comparing with the experimental results. By the numerical simulation, a dominant frequency component of the pressure fluctuation was captured and mechanism of the pressure fluctuation generation was predicted in the relation of horseshoe eddy structure and secondary flow around the elbow outlet.