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Seminar: Fluid Mechanics

Role of hydrophobicity and dissolved air on onset of nucleate boiling

Speaker: Yasuyuki Takata
Organization: Kyushu University
Time: 2019-03-27 14:00
Place: Teknikringen 8

Abstract

Wettability effect is one of the key parameters that influences boiling characteristics. The present study reveals the role of hydrophobicity in relation to the effect of dissolved air in liquid water. The hydrophobicity works as an excellent nucleation site and, therefore, by making use of biphilic surface the nucleate boiling is significantly enhanced. The boiling performance of biphilic surface is of about 7 times larger than that of mirror copper surface. This enhancement technique is very effective in subatmospheric condition. The effect of dissolved air on the onset of nucleate boiling (ONB) has been made clear by making use of a special experimental apparatus that can remove air from boiling water. It was found that the dissolved air assists early onset of boiling and enhances boiling performance.