Effect of Wall Wettability on LBE Two-Phase Flow

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K06959
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Nuclear engineering
• Research Institution: Kyoto University
• Principal Investigator: Saito Yasushi 京都大学, 複合原子力科学研究所, 教授 (40283684)
• Co-Investigator(Kenkyū-buntansha): 伊藤 大介 京都大学, 複合原子力科学研究所, 助教 (30630024)
• Research Collaborator: ARIYOSHI Gen ; INATOMI Ryota ; MAEDA Keisuke
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 液体重金属 / 加速器駆動システム / 鉛ビスマス共晶合金 / 気液二相流 / 速度計測法 / ボイド率計測法 / シビアアクシデント解析 / 電磁流速計

Outline of Final Research Achievements

Experimental and theoretical studies have been conducted on lead bismuth eutectic (LBE) - Nitrogen gas two-phase flow, by varying the wall wettability. To study the wall wettability, the wall wettability was changed by using soldering flux for the bubble column test sections. From measurement results, the wall wettability affected the two-phase flow behavior and its phase distributions. The distribution parameters C0 in the two-phase flow analytical model was estimated from experimental results, and compared to the theoretical analysis. The comparison shows that the wall wettability might affect especially the bubble behavior near the wall region.
For the forced convection experiments, "wall peak" distribution was observed for the void fraction and liquid velocity distributions. Such wall-peak distribution could be reproduced by theoretical model if the slip velocity on the wall surface is assumed for poor wattability conditions.

Free Research Field

原子力工学

Academic Significance and Societal Importance of the Research Achievements

本研究は、特に高レベル核廃棄物の減容を目的とした加速器駆動システム（ADS）の安全解析の高度化に必要な基礎的研究であり、特に壁面濡れ性が流動特性に与える影響は、材料腐食とともにシステムの安全性に重要な役割を果たす。この研究により、高温液体金属の詳細な流動構造を取得することが可能となり、さらに、理論的な予測法も開発できており、今後、ADSのみならず、液体金属を用いるシステムの高度化に極めて重要な知見を与えた。