A micro-gravity simulation of the Marangoni convection

An experimental verification of Marangoni convection in the liquid inter-space between two-coaxial discs is carried out at reduced gravity effect using small Bond's number obtained by choice of small characteristical diameter. Silicon oil is used as working fluid. The upper or lower disc can be heated electrically. The flow is visualized by illuminating fine powder of Titandioxide in the fluid with a vertical “light cut” of about 0.1 mm thickness, which is produced by a laser with a cylindrical glass rod and a microscope objective. Photographs and moving pictures are taken from a TV monitor. From these the vortex configuration and the velocity distribution can be determined, which would be expected for the Marangoni convection in the zero-g condition, for example in the spacelab.