Diffusion, Convection Phenomena under Reduced G-jitter

Abstract

In performing microgravity experiments, g-jitter is unavoidable in space stations, air planes and even in drop shafts. This acceleration affects convective motion in the experiments. A novel non-linear passive damper for microgravity experiments has been developed. The damper is small and does not consume electrical power. The performance of the damper in the Space Station has been estimated. They also measured diffusion coefficient of aqueous solution under microgravity and reduced g-jitter. The diffusion coefficient under the reduced g-jitter shows smaller value than that under normal gravity or with g-jitter. This tendency is similar to the anomalous diffusion decrease of water performed in the Mir Station. Crystal growth in microgravity experiments was measured under reduced g-jitter. The growth rate and surface super saturation were measured accurately using optical measurement system and numerical simulations. A comprehensive growth model applicable in micrograviy and normal gravity was developed.