U-RANS simulation of elbow flow with a 1/7 scale experimental loop simulating JSFR cold-leg piping

Yamano, Hidemasa   ; Kaneko, Tetsuya*; Aizawa, Kosuke ; Tanaka, Masaaki  ; Ebara, Shinji*; Hashizume, Hidetoshi*

In this study, Unsteady Reynolds Averaged Navier-Stokes equations (U-RANS) approach with the Reynolds Stress Model using a commercial computational fluid dynamics code has been applied to the flow through single and double short-elbows under a high Reynolds number condition (1.010). This numerical simulation has utilized a 1/7 scaled water experiment simulating the JSFR cold-leg piping in order to investigate the flow pattern in a three-dimensionally connected double elbow. As a result, validity and applicability of the U-RANS numerical simulation method were confirmed by comparison between the numerical and experimental results. The simulation has also shown that unsteady flow fields including vortex structures in the 1st elbow were very different from that in the 2nd elbow. This is because horseshoe vortexes generated in the 1st elbow downstream enter sideways the 2nd elbow. In addition, the simulation has indicated that the influence of distance between two elbows in the double elbow flow addressed in this paper was small.