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Thermocapillary convection in a shallow annular pool (depth d = 1 mm) of silicone oil (0.65 cSt, Pr = 6.7), heated from the inner wall, is investigated by numerical simulations. Under a fixed value of temperature difference between the outer and inner walls, surface temperature gradient in the inner heated pool is about 10% higher than that in the outer heated pool. Accordingly, the critical temperature difference for the incipience of HTW (ΔTc = 4.58K) is smaller than that (ΔTc = 5.0K) in the outer heated pool. Numerical simulations indicate that two groups of HTW, propagating in opposite azimuthal directions to each other, coexist and produce interference patterns in the inner heated pool. Rotation of the pool around its axis gives no significant influence on the behavior of HTW in the inner heated pool. The characteristics of HTW are discussed in contrast with those in the outer heated pool.Copyright © 2007 by ASME

The physical and mathematical models of the Marangoni convection of KF-96 silicone oil and FC-70 fluorinart in an encapsulated liquid bridge were established. To contrast to this configuration, the Marangoni convection of KF-96 silicone oil in a liquid bridge was also studied in present work. We conducted a series of unsteady two-dimensional numerical simulations. Simulation conditions correspond to those in the experiments of Majima and Kawamura (2001). The simulation results with large Marangoni number (Ma) predicted oscillatory flows under microgravity. The critical conditions for the onset oscillatory flow were determined and compared with the experimental results. Details of the flow and temperature fields were discussed. Oscillation frequencies were also exhibited.Copyright © 2005 by ASME

In order to understand the mechanism of the surface patterns on silicon melt in Czochralski furnaces, we conducted a series of unsteady three-dimensional numerical simulations of silicon melt flow in a rotating shallow annular pool in the counter-clockwise direction under micro-gravity. The pool is heated from the outer cylindrical wall and cooled at the bottom of an inner cylinder. The temperature differences between the vertical outer wall and the inner wall are 16 K, 21 K, 26 K and 32 K. Bottom and top surfaces of the melt pool are adiabatic. When the rotation rate is very slow, the hydrothermal waves are dominant in the pool and propagate in a direction opposite to the pool rotation. When the rotation rate exceeds the first critical value, the phase velocity of the hydrothermal waves increases rapidly and its propagating direction becomes same as that of the pool rotation. With much larger rotation rate, the flow becomes an axisymmetric steady flow. Details of the flow and temperature disturbances are discussed and the critical rotation rates are determined.Copyright © 2004 by ASME