Molecular diffusion and Boussinesq effects in heterogeneous fluid convection

摘要: The modelling of molecular diffusion in heterogeneous fluids, satisfying the Onsager hypothesis, always read as equations involving cross effects. In present paper, we show how double diffusive effects allow us to write uniformly valid asymptotic Boussinesq when medium is deep or, even, unbounded. This formulation introduces a small parameter e, namely, ratio vertical scale motion and related static state medium. reduce, inert mixtures, classical Fick's laws if at first order e. At second order, appear. non-inert appear order. By way applications, cases moist unsaturated air (inert ideal mixture), salt sea-water non-ideal mixture) saturated (non-inert mixture).