Measurements of Turbulent Flows in a 2x2 Rod Bundle
Turbulence models such as the k-ε model have been used in numerical predictions of turbulent flows in rod bundles. However, the validation of the turbulence models is not an easy task mainly due to the lack of experimental data on turbulent flows in rod bundles. In this study, we therefore measured three-dimensional velocity and turbulence intensities of water flows in a 2x2 rod bundle by using a PIV system. The diameter and pitch of the rods were 20 and 25 mm, respectively. The mean velocity ranged from 1 to 2 m/s. To measure velocity distribution in the whole subchannel, the rod in the measurement region was made of fluorinated ethylene propylene resin (FEP), refractive index of which is almost the same as that of water. The time-averaged velocity and turbulent intensities were obtained from 10,000 instantaneous velocities. Time-series velocity distributions were also acquired to discuss motion of turbulence eddies in the subchannel. The experimental results indicate that the axial mean velocity at the center of subchannel is by 27％ higher than that at the center of rod gap, and that the axial turbulence intensity along the centerline of the subchannel takes a peak between the gap and the center of the subchannel. Numerical simulations using the k-ε model were carried out to examine the applicability of the k-ε model to the turbulent flow in the rod bundle.
Turbulence Rod bundle Particle image velocimetry k-εturbulence model
Jun Okajima Shigeo Hosokawa Taishi Yamamoto Akio Tomiyama
Graduate School of Engineering,Kobe University 1-1 Rokkodai,Nada,Kobe 657-8501
国际会议
上海
英文
1260-1271
2010-10-10（万方平台首次上网日期，不代表论文的发表时间）