Description of the adhesive crystal growth under normal and micro-gravity conditions employing experimental and numerical approaches

Investigation of the crystal growth in solutions is closely related to effective and high quality production of medicine, food and new materials. In the present study, experiments and numerical simulations were performed to explain the mechanism of crystal growth from an aqueous solution. In the experiment, transient double diffusion fields were observed by using an accurate optical measuring system. In the numerical simulation, transient double diffusion fields were calculated by a numerical simulation code, applying initial and boundary conditions obtained by experiment. The results of numerical simulation show good agreement with experimental results. Taking these two approaches into consideration, it was considered that adhesive crystal growth was dominated by the temperature dependence of the solutal diffusion coefficient. The microscopic mechanism of adhesive crystal growth is almost the same between microgravity and normal gravity conditions; nevertheless, the macroscopic growth rate is different in each situation. Simulation of adhesive crystal growth can be performed easily using appropriate boundary conditions obtained by the present experiments. (C) 2002 Published by Elsevier Science B.V.