Study on a new simple prediction method of the melting in the complex convection

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K04231
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 19020:Thermal engineering-related
• Research Institution: Akita University
• Principal Investigator: Masahide Nakamura 秋田大学, 名誉教授, 名誉教授 (60172441)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 相変化 / 自然対流 / エネルギー貯蔵 / 融解

Outline of Final Research Achievements

Melting of ice layers in low freezing aqueous solutions is an important issue associated with the energy storage. In this study, the diffusion coefficient was predicted from the Stokes-Einstein relation, its correction formula, and the formula for the viscosity of the suspension, and the prediction formula of the melting amount was derived. Next, the melting experiment of the horizontal ice plate was performed. As a result, if the constant included in this prediction formula is selected correctly, the agreement with the experimental results will be better when the solute is the calcium chloride or magnesium chloride, but not when the solute is the sodium chloride. Furthermore, by visualizing the flow near the melting surface, it was clarified that when the solute is the sodium chloride, it has a slightly peculiar property that natural convection in the aqueous solution is maintained for a long time.

Free Research Field

機械工学

Academic Significance and Societal Importance of the Research Achievements

相変化はエネルギー貯蔵の面からも注目されている。本研究は、相変化を理解するための重要な基礎となるものであるため、今後新たなエネルギー貯蔵方法を開発するための基礎として重要な役割を演ずる可能性がある。そのため社会的な意義がある。また本研究から、溶質の種類が融解に与える影響について興味深い知見が得られたことは重要で、このことは学術的な意義があるものと思われる。