The entropy generation Eq. (19) may be useful to explore the
entropy generation mechanisms in thermal non-and quasi-equilibrium.
Eq. (19) is the governing equation for the second law of thermodynamics.
The internal heat generation per unit length
q0
i ¼ T0s0=k is also obtained by comparing Eq. (1) with Eq. (21). This
means internal thermal convection plays the role of source in the
thermal diffusion equation.
During quasi-equilibrium heat transfer, two irreversible processes
are possible:The constraint for the particle number constants is b2 = k2.
During the isothermal process (TS = jT T0j = 0), Eq. (19) yields
the equation for entropy diffusion