NUMERICAL COMPUTATION OF HEAT-FLOW, FLUID-FLOW AND INTERFACE SHAPES IN THE FLOAT-ZONE OF LITHIUM-NIOBATE DURING A MELTING PROCESS

Computer simulations were performed to study the temperature and veloc ity distributions and the interface shapes in the floating-zone melt f or Lithium niobate materials. The input power distribution generated b y the heat source was assumed to be Gaussian. The variation of the int erface shapes and the transport phenomena in the flow zone relative to the input power was investigated. The results show that the shapes of the gas-melt and melt-solid interfaces and the temperature and veloci ty fields are modified by the gravity force; the influence of gravity increases as the input power increases. The present results are consis tent with the recent experimental observations. Copyright (C) 1996 Els evier Science Ltd.