A Study on Light Control for Heat Transfer Performance Using Photo-sensitive Viscoelastic Fluids

2015 Fiscal Year Final Research Report

• Project/Area Number: 26630064
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Thermal engineering
• Research Institution: Kyoto University
• Principal Investigator: Nakabe Kazuyoshi 京都大学, 工学(系)研究科(研究院), 教授 (80164268)
• Co-Investigator(Kenkyū-buntansha): TATSUMI Kazuya 京都大学, 大学院工学研究科, 准教授 (90372854)
• Project Period (FY): 2014-04-01 – 2016-03-31
• Keywords: 対流 / 機能性流体 / 熱伝達 / 光制御 / 粘弾性 / 異性体

Outline of Final Research Achievements

To develop innovative methods to effectively control the heat transfer performance of heat exchangers, we investigated the easy-and-active control of heat transfer rates using photo-sensitive viscoelastic fluids, the properties of which can be tuned by light wavelength. A photo-sensitive chemical (OMCA) was added to an aqueous mixture of surfactants and counter-ions, the solution of which induces the formation of wormlike micelles. OMCA has trans- and cis-arrangements of the substituents, and trans-OMCA irreversibly undergoes a photo-isomerization to cis-OMCA upon exposure to UV light and shortens the micelles, so that the viscoelasticity of the aqueous solution as a working fluid of heat transfer becomes weaker as the exposure time increases. As a result, both the heat transfer coefficient and pressure loss penalty were decreased irreversibly with an increase in the exposure time, which implies attractive and realizable possibility for the light control of heat transfer.

Free Research Field

熱材料力学分野