Open AccessEvaporation induced solidification of cyclohexane drops under acoustic levitation condition
Author(s) -
Du Ren-Jun,
Wenjie Xie
Publication year - 2011
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.60.114302
Subject(s) - materials science , drop (telecommunication) , cyclohexane , evaporation , nusselt number , levitation , mechanics , natural convection , thermodynamics , acoustic levitation , liquid drop , heat transfer , composite material , chemistry , reynolds number , physics , magnet , mechanical engineering , turbulence , engineering , organic chemistry , quantum mechanics
The evaporation process of a cyclohexane drop is investigated by single-axis acoustic levitation method. It is found that the evaporation of the cyclohexane drop results in the decrease of its temperature below the melting point, and leading to solidification. The real-time observation with a high speed camera shows that the cyclohexane nucleates near the equator of the drop surface and grows dendritically with an average velocity ranging from 12.5 to 160.4 mm/s. Further studies indicate that the ratio Sh/Nu of the average Sherwood number to Nusselt number under acoustic levitation condition is 1.3 times of that under natural convection condition. This suggests that the acoustic streaming boundary layer effectively strengthens the evaporation but has less promotion effect on the heat transfer. Therefore, the drop temperature declines to a lower value and the evaporation induced solidification occurs under acoustic levitation condition. Accordingly, a necessary condition for the occurrence of evaporation induced solidification of volatile liquids is proposed.