Theoretical Study of Heat and Mass Transfers

The process of heat and mass transfers through the tri-layer films is similar to that in bilayer films. Thus the theoretical treatment described in Section 3.3.1 is of value for the heat transfer, and the theoretical treatment described in Section 3.3.2 can be used for the mass transfer controlled by diffusion. 

When the thermal parameters are constant, Equation (3.16) can be used in the case of forced convection on both surfaces with the same coefficient of convective convection which appears in Equation (3.17) expressing the dimensionless number Rj.  

However, a numerical treatment is made, based on finite differences, for the following two reasons the thermal parameters are temperature-dependent, and the diffusivity of the coupled mass transfer controlled by diffusion is also temperature-dependent. 

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