Fluid transport in capillary systems under microgravity

The wetting kinetics of model tubes of different geometries has been investigated experimentally and theoretically under conditions of simulated zero-gravity and microgravity. Numerical calculations of meniscus configurations and the rise of the menisci in tubes of different shape are compared with photographic pictures obtained from sounding rocket experiments (TEXUS-Programme). It is demonstrated that menisci under microgravity conditions are essentially different from those of simulated zero-g-experiments. These results, together with observed streamline patterns, yield valuable information with respect to the hydrodynamic deformation of phase interfaces and dynamic contact angles.