Comment on "Convective heat transfer law for an endoreversible engine" [J. Appl. Phys. 100, 014911 (2006)]

In this Comment we emphasize that the Huleihil and Andresen approximation for the exponent of the convective heat transfer law expressed as n=1+epsilon, with epsilon a small number which is representative of convective heat transfer, is a reasonable proposal, and additionally it works well for another optimization criteria. We also show that some of the main analytical results of the article [M. Huleihil and B. Andresen, J. Appl. Phys. 100, 014911 (2006)] are particular cases of expressions previously published in the article [L.A. Arias-Hernandez, G. Ares de Parga, and F. Angulo-Brown, Open Syst. Inf. Dyn. 10, 351 (2003)] where internal irreversibilities were included in the engine models. (c) 2007 American Institute of Physics.