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Iwamoto, Yukiharu*; Yamano, Hidemasa
Proceedings of 4th International Conference on Jets, Wakes and Separated Flows (ICJWSF 2013) (CD-ROM), 6 Pages, 2013/09
Wall pressure measurements were made for a 90 degree elbow of which the axis curvature coincided with its inner diameter (125 mm). Reynolds numbers examined were 3.2 
10
and 5.0 10. Results showed that distributions of fluctuating normalized pressures obtained here and the result made by Shiraishi et al. for the Reynolds number of 3.25 10
coincided one another within 0.02 of the dynamic pressure. The peak spectrum with the Strouhal number of 0.5 could be found in the inner region downstream of the elbow. They correspond to the vortex shedding from the boundary layer developed in the inner and aft part of the elbow. The peak intensity having the Strouhal number of 0.5 quantitatively coincided with the data obtained in the experimental setup that Shiraishi et al. used, suggesting that the law of dynamical similarity could be applied with regard to this oscillation.
Takase, Kazuyuki; Misawa, Takeharu; Yoshida, Hiroyuki
Proceedings of 4th International Conference on Jets, Wakes and Separated Flows (ICJWSF 2013) (CD-ROM), 6 Pages, 2013/09
For the thermal design of supercritical water reactors, it is necessary to develop an analysis method to correctly predict turbulent heat transfer characteristics in subchannels of fuel bundles. Spacers are set into the subchannels to keep a distance between adjacent fuel rods. The turbulent heat transfer generally enhances by reduction of cross-sectional area in the subchannels due to the existence of the spacers. However, since thermo-physical properties of supercritical fluids drastically change at the vicinity of the pseudocritical point, the enhancement of the turbulent heat transfer depends on the thermal design. Then, the Japan Atomic Energy Agency is developing the analysis method to predict thermal-hydraulic characteristics of the supercritical fluids. The heat transfer calculations were performed using a newly developed code under the condition of a subchannel with a specer, and the enhancement of the turbulent heat transfer coefficient in subchannels with the spacer was analyzed numerically.
Hanari, Toshihide; Muramatsu, Toshiharu; Yamashita, Masanori*; Sakakibara, Jun*
no journal, ,