Shape measurement and dry-out mechanisms of a falling liquid film on a wall under thermal radiation

2023 Fiscal Year Final Research Report

• Project/Area Number: 19K04197
• 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: Shibaura Institute of Technology
• Principal Investigator: Tange Manabu 芝浦工業大学, 工学部, 准教授 (70549584)
• Co-Investigator(Kenkyū-buntansha): 大宮 喜文 東京理科大学, 創域理工学部建築学科, 教授 (10287469) ; 小野 直樹 芝浦工業大学, 工学部, 教授 (20407224)
• Project Period (FY): 2019-04-01 – 2024-03-31
• Keywords: 伝熱工学 / 火災安全

Outline of Final Research Achievements

To investigate the radiation heat shielding phenomenon of the wall surface downward water film for preventing the spread of fire in buildings, we studied the falling liquid film on a radiation-heated wall surface to clarify the effects of the liquid film shape and velocity distribution within the liquid film on the occurrence of dry patches. Specifically, a water film was formed on a glass wall surface at various flow rates, and the glass wall surface was heated from the water film side by a radiation panel. We develop a method to measure the thickness distribution and velocity distribution within the liquid film by measuring the three-dimensional position and velocity of the tracer particles. The possibility of measuring the internal flow velocity distribution of the water film by astigmatism PTV was demonstrated. It was also suggested that the liquid film rupture condition due to radiation overheating may differ from that due to wall overheating.

Free Research Field

伝熱工学

Academic Significance and Societal Importance of the Research Achievements

これまでマイクロ流路などで用いられていた流速の三次元計測手法を水膜内部の流速計測に適用した．これによって，壁面上の流下水膜が延焼防止に与える影響について，詳細に調査することができ，安全を確保しながらも使用水量を節約できる延焼防止システムの開発に寄与できるものと考える．