A volumetric 3D measurement tool for velocity field diagnostics in microgravity experiments

An optical whole-field 3D particle tracking velocimetry tool for diagnostic s in microgravity experiments is presented. To demonstrate the potential of the technique it is applied to a Marangoni convection experiment and to a flow within a fluid column, as typical microgravity experiments. In experim ents under gravity conditions in an observation volume for the Marangoni ex periment of 20 x 14 x 14 mm(3), 200-500 velocity vectors per time instant c ould be determined, whereas in the fluid column experiment the observation volume was 40 x 40 x 15 mm(3), and up to 850 velocity vectors per time inst ant could be determined.