Analyses of the characteristics of crystal growth from solution under microgravity III. Effects of the orientation of microgravity

Abstract The characteristics of crystal growth from solution under microgravity are analyzed using a cuboidal model. A set of partial differential equations is numerically solved to study the effects of the orientation of gravity on the distribution of solute concentration and of temperature, fluid velocity and growth rate of crystal. Two extreme cases of the Rayleigh number Ra are taken into account. In the case of small Ra (Ra 4 ), the results for the angle y between the vector of gravity and the - y axis are essentially the same as those for - y , and only the y component of gravity should be of concern. The convection of solution is the strongest at the angle γ = O ° and weakens with the increase of |γ|. In the case of large Ra (Ra 5 x 10 5 ), the results for γ are obviously different from those for - y . The convection of solution is the strongest at a certain angle unequal to zero.