TY - EJOU AU - Yan, Y. AU - Shevtsova, V. AU - Saghir, M. Z. TI - Numerical Study of Low Frequency G-jitter Effect on Thermal Diffusion T2 - Fluid Dynamics \& Materials Processing PY - 2005 VL - 1 IS - 4 SN - 1555-2578 AB - Convection has a major impact on diffusion in fluid mixtures either on the Earth or in the microgravity condition. G-jitters, as the primary source that induces the vibrational convection in space laboratories, should be studied thoroughly in order to improve the diffusion-dominated fluid science experiments. In this paper we consider the effect of g-jitters on thermal diffusion. The mixture water-isopropanol (90:10 wt%) bounded in a cubic cell is simulated with a lateral heating and various vibration conditions. The fluid flow, concentration and temperature distributions are thoroughly analyzed for different g-jitter scenarios. It is shown that the overall effect of vibrations on diffusion can be regarded basically as a nonlinear interaction between the effects caused by each individual g-jitter component. In the presence of large static residual gravity, the effect of convection on diffusion is very significant, thus resulting in a limited Soret separation. On the contrary, the importance of periodic vibration on diffusion changes according to the frequency. Low frequency vibrations exhibit a more dangerous effect on diffusion measurements with respect to high frequency vibrations. The dependence of the Soret separation on frequency and the driving mechanisms at low frequency g-jitters are discussed on the basis of these behaviors. KW - Thermal diffusion KW - Convection KW - Numerical simulation KW - Finite volume KW - Microgravity KW - G-jitter DO - 10.3970/fdmp.2005.001.315