Re: What is Soret effect?
The soret effect is where small light molecules and large heavy molecules separate under a temperatue gradient. Usually this effect is important where more than one chemical species is present under a very large temperature gradient such as CVD problems and chemical reactors. This effect is found when solving the species mass fraction equations.
The Dufour effect describes the energy (heat) flux created when a chemical system is under a concentration gradient. This could also be important in CVD problems. This effect is found in the energy equation. The soret coefficient is the ratio of the thermal diffusion coefficient divided by the ordinary diffusion coefficient. |
Re: What is Soret effect?
Dear Zeng
Dufour Effect : Concentration gradients produce a heat flux. Soret Effect : Reverse of Dufour effect It is known that both Soret & Dufour effects are negligible, for most applications. Sincerely, Jinwook |
Re: What is Soret effect?
Soret effect- This is a mass flux due to a temperature gradient and appears in the species continuity equation when you have a multicomponent mixture where each species has its own diffusional velocity.
Dufor Effect-This is enthalpy flux due to a concentration gradient and appears in the energy equation for a multicomponent mixture.These effects depend on thermal diffusion which is generally very small but can be sometimes significant when the participating species are of widely differing molecular weights Venkat |
What is Soret effect?
Can you help me to understand: (1) Soret effect (2) Soret diffusion coefficent (3) Dufour effect
Thanks in advance. |
soret effect
In isothermal mixtures of two or more species (gases, liquids and even liquid mixtures Soret (Ludwig-Soret) effect.solids), mass diffusion occurs if the species are initially distributed unevenly, i.e., when a concentration gradient exists. A temperature gradient can also work as a driving force for mass diffusion, in a phenomenon which is called thermodiffusion, thermal diffusion, or in Free open access paper on Soret effect http://www.thermalfluidscentral.org/...hp?a=206&g=242 |
Hi, as far as I know, Soret effect is not negligible when you compute the transport of light species (typically H radical in combustion applications).
Cheers. |
soret effect
Whenever there is a temperature gradient in the mixture, Soret effect is present. The higher the temperature gradient, the larger the Soret effect. Pressure diffusion is usually negligible but not the Soret effect.
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Sorret and Dufour effect on forced convection
Hey, in the case of forced convection can we study the effect of Soret and Dufour ???
If the answer is yes, it makes a notable difference when we neglect these parameters ? Thanks in advance :) |
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