The Dufour effect

Abstract

Equations for the Dufour effect, which is the development of a temperature gradient due to diffusion, have been solved for geometrically well-defined cells which have either all walls adiabatic or adiabatic lateral walls and diathermic ends. Two self-consistent, well-ordered perturbation schemes have been used, and heat of mixing, variability of all properties, and the barycentric velocity are included explicitly. For typical nonelectrolytes, the temperature difference produced by the Dufour effect could be as large as 0.2 deg for a diffusing mixture with initial mass fraction difference of 0.8. These results can be used (I) to design experiments to test the ~nsager heat-matter reciprocal relation and (2) to avoid undesired temperature variations in diffusion experiments.

Theoretical and numerical analysis of a heat pump model utilizing Dufour effect

“…(a −1−1 a 11 − a 2 1−1 ), (A. 13) using the similar derivation to the three-dimensional expression in reference [14].…”

On the validity of the Onsager relations in an inert multiple dilute gas mixture

“…This representation in terms of the chemical potential or the concentration is the most commonly reported in experimental measurements [7,[9][10][11][12]. This representation in terms of the chemical potential or the concentration is the most commonly reported in experimental measurements [7,[9][10][11][12].…”

Triple diffusive convection with Soret–Dufour effects in a Maxwell nanofluid saturated in a Darcy porous medium

“…In gases, the difference can reach several degrees (for example, for nitrogen with hydrogen it measures approximately 10 3 °C). Ingle and Horne [25] mentioned that the effect is of interest in liquids for three important reasons: (1) it can be used to verify the heat matter Onsager reciprocal relation, (2) the temperature variations could cause complications in diffusion experiments, and (3) it has never been unambiguously observed. In 1879, a reverse phenomenon of thermo-diffusion in liquids was observed by another Swiss Scientist Soret [26].…”

“…But there are exceptions; Eckert and Drake [28], Nithyadevi and Yang [29] and Weaver and Viskanta [30] discovered several cases where the Soret and/or Dufour effects cannot be ignored. These effects are often encountered in chemical process engineering, in the area of reactor safety, in combustion flames, in high-speed aerodynamics, in oceanography, in solar collectors and in various porous flow regimes occurring in geophysical systems [25,28]. Ryskin et al [31] considered the Soret effect in ferromagnetic nanofluid and showed that nanoparticles inhibit the stability of the system in comparison with the conventional fluid.…”