Results are presented from body-fitted coordinate finite-volume analysis of the floating-zone (FZ) growth of tube crystals based on a thermal-capillary model. The model governs the steady-state and conduction-dominated heat transport in the system and simultaneously determines the shapes of melt/solid interfaces and melt/air free surfaces, and the size of the steadily growing tube crystal. Calculations are mainly performed for the FZ growth of silicon. The effects of heat input, growth speed, growth direction, internally applied pressure, and feed tube size on the dimension of the crystal as well as on the shapes of the melt/solid interfaces and the melt/air free surfaces are predicted for the FZ tube growth system. Caused by the contractive force of free surfaces, the inner free surface is concave toward the axis, thus resulting in a decrease in the size of the grown tube for both upward and downward growth. However, an overpressure inside the tube can counterbalance the contractive force and increases the grown tube size. Simulation is also conducted for electron beam FZ growth of the tungsten tube. The calculated inner and outer radii of the crystal agree reasonably well with the experiment of Glebovsky et al.
