Within the framework of the phenomenological theory of turbulence of compressible chemically active gas continuum the thermodynamic approach to the problem of closure of hydrodynamic equations of average motion of a mixture at the level of the first-order models is considered. The Onzager formalism of nonequilibrum thermodynamics allows to obtain the most common structure of rheological relations for turbulent flows of diffusion and turbulent flow of heat in a multicomponent mixture, in particular, in the form of the generalized Stefan–Maxwell relations for turbulent flows of milticomponent diffusion. As an example, the detailed derivation of similar relations for a small-scale turbulence is considered, when the tendency to establishment of a local statistical isotropy in a flow is observed. On the considered level closing closure obtained defining relations of 'forces through flows' most fully describe the turbulent heat- and mass transfer in multicomponent gas mixture.

irreversible thermodynamics, multicomponent continuum, developed turbulence, model circuit of the first order

Mathematical modelling in actual problems of science and technics