INFLUENCE OF SEED CRYSTAL DIMENSION ON CRYSTAL GROWTH FROM SOLUTION UNDER MICROGRAVITY

The influence of the dimension of seed crystal on the characteristics of crystal growth from solution under microgravity is studied. The dimensionless average velocity of fluid V_av, the dimensionless maximum velocity of fluid V_max, the temperature distribution index S_\theta, the concentration distribution index S_\phi and the dimensionless average growth rate of crystal \overlineV_\rm cg are calculated by only taking into account the variation of the solution density caused by the temperature change, that caused by the concentration change being neglected. In certain regions of the parameter (Ra, Pr, Sc and \mu) space, some scaling laws are generated: the scales of S_\phi and \overlineV_\rm cg are given by power functions of \mu with negative exponents. It is shown that the characteristics of crystal growth for small seed crystal are different from those for large seed crystal.