Experimental measurement of Soret coefficient and numerical study on effect of g-jitter in liquid mixtures

A ground based experiment using digital optical interferometry was conducted to measure the Soret and thermodiffusion coefficients of a liquid binary mixture of water-isopropanol with different mass fractions in a rectangular glass cell. The cell was subjected to a temperature gradient of 6^oC, and the entire experimental setup was placed inside a heat insulation box. The results showed good agreement with published results and established that the method of measurement is a competitive and accurate method to measure the transport coefficients in binary liquid mixtures. In preparation for IVIDIL (influence of vibrations on diffision in liquids) experiments on board the International Space Station, a numerical analysis for the mixture of water-10% isopropanol was performed to determine the effects of g-jitter on the flow inside a cylindrical model subject to a temperature gradient of 10^oC. The data for g-jitter, Soret and thermodiffusion coefficients were obtrained fom FOTON-12 and used in the analysis. A comparison between zero-gravity, micro-gravity and g-jitter scenarios showed that the presence of g-jitter does affect the flow inside the cell. Temperature and concentration times to reach the steady state were increased.