| Original Articles |
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Experimental Study on Liquid Free Surface in Buoyant-Thermocapillary Convection |
| DUAN Li;KANG Qi;HU Wen-Rui |
| National Microgravity Laboratory (CAS), Institute of Mechanics, Chinese Academy of Sciences, Beijing 100080 |
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| Cite this article: |
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DUAN Li, KANG Qi, HU Wen-Rui 2008 Chin. Phys. Lett. 25 1347-1350 |
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Abstract We investigate the surface deformations of buoyant-thermocapillary convection in a rectangular cavity due to gravity and temperature gradient between the two sidewalls. The cavity is 52×42mm in horizontal cross section, the thickness of liquid layer h is changed from 2.5mm to 6.5mm. Surface deformations of h= 3.5mm and 6.0mm are discussed and compared. Temperature difference is increased gradually, and the flow in the liquid layer will change from stable convection to unstable convection. Two kinds of optical diagnostic system with image processor are developed for study of the kinetics of buoyant-thermocapillary convection, they give out the information
of liquid free surface. The quantitative results are calculated by Fourier transform and correlation analysis, respectively. With the increasing temperature gradient, surface deformations calculated are more declining. It is interesting phenomenon that the inclining directions of the convections in thin and thick liquid layers are different. For a thin layer, the convection is mainly controlled by thermocapillary effect. However, for a thick layer, the convection is mainly controlled by buoyancy effect. The surface deformation
theoretically analysed is consistent with our experimental results. The present experiment proves that surface deformation is related to temperature gradient and thickness of the liquid layer. In other words, surface deformation lies on capillary convection and buoyancy convection.
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| Keywords:
47.20.Bp
47.20.Dr
47.27.Nd
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Received: 29 November 2007
Published: 31 March 2008
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| PACS: |
47.20.Bp
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(Buoyancy-driven instabilities (e.g., Rayleigh-Benard))
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47.20.Dr
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(Surface-tension-driven instability)
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47.27.nd
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(Channel flow)
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[1] Burguete J et al 2001 Phys. of Fluids 13 2773
[2] Schatz M F et al 2001 Ann. Rev. Fluid Mech. 33 93
[3] Sen A K and Davis S H 1982 J. Fluid Mech. 121163
[4] Shu J Z et al 1994 Microgravity Sci. Technol. 7 83
[5] Ezersky A B et al 1993 Phys. Rev. E 47 1126
[6] Duan L, Kang Q and Hu W R 2006 Sci. Chin. E 49601
[7] Kang Q, Duan L and Hu W R 2004 Microgravity Sci.Technol. X$\!$V 18
[8] Dabiri D and Gharib M 2001 Exp. Fluids 30 381
[9] Leneweit G et al 1999 Exp. Fluids 26 75
[10] Lapham G S et al 2001 Exp. Fluids 30 448
[11] Saylor J R et al 2000 Exp. Fluids 29 509 |
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