Numerical investigation on practicability of reducing MCST by using grid spacer in a tight rod bundle

Xiaojing Zhu*, Shinichi Morooka, Yoshiaki Oka


    研究成果: Article査読

    12 被引用数 (Scopus)


    The numerical investigation was carried out to reveal the practicability of reducing the maximum cladding surface temperature (MCST) within the inner sub-channel of a tight, hexagon rod bundle using commercial CFD code STAR CCM+ 6.04. The special heat transfer and pressure drop characteristics caused by four existing grid spacer designs were discussed in detail by analyzing the effects of grid strap length, different flow enhancing features and different Reynolds numbers. It was found that the local heat transfer within the grid strap is greatly enhanced due to the raised flow velocity. Both the standard grid spacer and the grid spacer with split-vanes cause decreased heat transfer in the downstream region. The friction drag is very influential in the tight rod bundle and can eliminate the positive effect of flow blockage on the heat transfer performance. The grid spacer with flow blockage discs induces relatively good heat transfer performance and higher pressure drop within sub-channels, indicating a tradeoff between the heat transfer augmentation and the pressure drop. The combination of multiple existing grid spacers can reduce the MCST to a certain level, but the corresponding disadvantages cannot be ignored. The improved grid spacer design was proposed based on the overall considerations of heat transfer and pressure drop characteristics and has been proved more suitable to widely reduce MCST for SCWR than any other grid spacer designs involved in present study.

    ジャーナルNuclear Engineering and Design
    出版ステータスPublished - 2014 4月 15

    ASJC Scopus subject areas

    • 原子力エネルギーおよび原子力工学
    • 機械工学
    • 安全性、リスク、信頼性、品質管理
    • 材料科学(全般)
    • 核物理学および高エネルギー物理学
    • 廃棄物管理と処理


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