 it reduces to the popular form of Stanton number ("St") increasing with increasing "Re", whereas for variable μ it reduces to "St" increasing with decreasing "Re".Consequently, the Chilton-Colburn analogy of "St"•"Pr"2/3 increasing with increasing "c"f is qualitatively valid whenever the
Reynolds’ analogy is valid.Further, the validity of the Reynolds’ analogy is linked to the applicability of Prigogine's Theorem of Minimum Entropy Production.