Effect of Marangoni number on thermocapillary convection and free-surface deformation in liquid bridges

The influence of airflow shear on the free surface deformation and the flow structure for large Prandtl number fluid (Pr = 111.67) has been analyzed numerically as the parallel airflow shear is induced into the surrounding of liquid bridge from the lower disk or the upper disk. Contrasted with former studies, an improved level set method is adopted to track any tiny deformation of free surface, where the area compensation is carried out to compensate the nonconservation of mass. Present results indicate that the airflow shear can excite flow cells in the isothermal liquid bridge. The airflow shear induced from the upper disk impulses the convex region of free interface as the airflow shear intensity is increased, which may exceed the breaking limit of liquid bridge. The free surface is transformed from the “S”-shape into the “M”-shape as the airflow shear is induced from the lower disk. For the nonisothermal liquid bridge, the flow cell is dominated by the thermocapillary convection at the hot corner if the airflow shear comes from the hot disk, and another reversed flow cell near the cold disk appears. While the shape of free surface depends on the competition between the thermocapillary force and the shear force when the airflow is induced from the cold disk.

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A new experimental technique for measuring the dynamical free surface deformation in liquid bridges due to thermal convection

Measurement Science and Technology ◽

10.1088/0957-0233/19/1/015410 ◽

2007 ◽

Vol 19 (1) ◽

pp. 015410 ◽

Cited By ~ 17

Author(s):

C Ferrera ◽

J M Montanero ◽

A Mialdun ◽

V M Shevtsova ◽

M G Cabezas

Keyword(s):

Free Surface ◽

Experimental Technique ◽

Thermal Convection ◽

Surface Deformation ◽

Liquid Bridges ◽

Free Surface Deformation

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Thermosolutocapillary Convection in an Open Rectangular Cavity With Dynamic Free Surface

Journal of Heat Transfer ◽

10.1115/1.4029270 ◽

2015 ◽

Vol 137 (8) ◽

Cited By ~ 9

Author(s):

Xiaoming Zhou ◽

Xiulan Huai

Keyword(s):

Free Surface ◽

Aspect Ratio ◽

Capillary Number ◽

Marangoni Number ◽

Surface Deformation ◽

Central Zone ◽

Deformation Mode ◽

Rectangular Cavity ◽

Left Wall ◽

Free Surface Deformation

Thermosolutocapillary convection within a rectangular cavity with dynamic free surface is numerically investigated in the absence of gravitational effects. Both the temperature and solute concentration gradients are applied horizontally. The free surface deformation is captured by the level set method. Two cases of the ratio of thermal to solutal Marangoni number Rσ < −1 and Rσ = −1 are considered. For Rσ < −1, the free surface bulges out near the left wall and bulges in near the right wall; with the increase of Marangoni number, the free surface deformation decreases and with the increase of capillary number and aspect ratio, it increases. For Rσ = −1, the free surface bulges out near the left and right walls and bulges in at the central zone; with the increase of Marangoni number, the free surface deformation mode is changed and with the increase of capillary number and aspect ratio, the free surface deformation increases.

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