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Abstract
The three-dimensional numerical simulations of spoke pattern in a vertical cylinder (like the Bridgman top seeding convection) were performed. The fluid was assumed to be incompressible, Newtonian, and Boussinesq. Comparison of numerical result and experimental observation given by Kowalewski and Cybulski of evolution of spoke pattern has shown good agreement. Calculations were presented at a Rayleigh number in the range between 1.3 2 10 5 and 1.3 2 10 7 (for the transient region from laminar to turbulent flow). With increasing Grashof number the flow structure became unsteady and unstable, and the vertical "cold jet" became dominant in the melt. The Rayleigh-Benard instability is an indispensable factor in forming the surface spoke pattern in Bridgman top seeding convection.