Elucidation of ice slurry flow with heat transfer by microscopic approach including solid-liquid phase change

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K03873
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 19010:Fluid engineering-related
• Research Institution: Shinshu University
• Principal Investigator: YOSHINO Masato 信州大学, 学術研究院工学系, 教授 (00324228)
• Co-Investigator(Kenkyū-buntansha): 鈴木 康祐 信州大学, 学術研究院工学系, 准教授 (10735179) ; 浅岡 龍徳 信州大学, 学術研究院工学系, 准教授 (30508247)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 格子ボルツマン法 / 氷スラリー流 / 固液二相流 / 融解・凝固 / 相変化 / 平均ヌッセルト数

Outline of Final Research Achievements

We constructed a numerical model for simulation of melting and solidification, and then developed a thermal immersed boundary-lattice Boltzmann method with solid-liquid phase changes. First, using this method, we calculated heat-transfer (Stefan) problems, demonstrating the validity of the method in comparison with a reference solution by the finite-difference method. Next, we applied the method to ice slurry flows in a circular tube, where numerous spherical particles were subjected to the particle-particle and particle-wall adhesion models. We investigated the effects of the aggregated particles (clusters) on the flow characteristics and temperature fields as well as the space-averaged Nusselt number. Also, taking account of buoyancy effect, we computed how the particles were distributed in the radial direction of the tube. Finally, on the basis of these results, we discussed the characteristics of flow and heat transfer from the microscopic point of view.

Free Research Field

数値流体力学

Academic Significance and Societal Importance of the Research Achievements

本研究で開発した熱流動計算法は，複雑流れに対してもアルゴリズムが簡単な格子ボルツマン法と，任意形状の境界を扱う問題に対して複雑なメッシュ生成が不要な埋め込み境界法を組み合わせた計算効率の高い手法であり，これに融解・凝固の固液相変化を組み込んだ計算手法はこれまでにあまり例がなく，学術的な意義は大きい．また，固体粒子一つ一つを十分な空間解像度で表現することが可能であることから，氷スラリーのような移動境界を伴う熱流動問題の計算に対して有効である．