Perturbed Energy Equation for Small Peclet Number

2 Perturbed Energy Equation for Small Peclet Number 

The first terms on the left and right-hand sides of Eq. (11.27) are on the order of St and Pe respectively, whereas the second and third terms on left-hand side of Eq. (11.27) have the order of one. When Pe C 1 and St 3 1 it is possible to omit the terms accounting for convective heat transfer due to oscillations and present Eq. (11.17) as follows  

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