Abstract:In order to understand the nature of surface patterns on siliconmelts inindustrial Czochralski furnaces, we conducted a series of unsteadythree-dimensional numerical simulations of thermocapillary convections inthin silicon melt pools in an annular container. The pool is heated from theouter cylindrical wall and cooled at the inner wall. Bottom and top surfacesare adiabatic. The results show that the flow is steady and axisymmetric atsmall temperature difference in the radial direction. When the temperaturedifference exceeds a certain threshold value, hydrothermal waves appear andbifurcation occurs. In this case, the flow is unsteady and there are twopossible groups of hydrothermal waves with different number of waves, whichare characterized by spoke patterns traveling in the clockwise andcounter-clockwise directions. Details of the flow and temperaturedisturbances are discussed and number of waves and traveling velocity of thehydrothermal wave are determined.