Thermocapillary flow near a “cold corner”

The velocity field in a neighborhood of the point of contact between the free and solid boundaries is studied numerically for the problem of noncrucible zone melting in a two-dimensional model formulation. A distinct Prandtl boundary layer on the solid boundary and a Marangoni boundary layer on the free boundary and high gradients of the longitudinal velocity along the free boundary in the immediate vicinity of the “cold corner” are observed. It is found for the first time that with distance from the solid boundary, the velocity curve has a maximum, which is not typical of the ordinary flow near the solid boundary.