In this letter, it is shown that the applied relations
in the paper by Hakan O¨ zcan [H. O¨ zcan, The effects
of heat transfer on the exergy efficiency of an air-standard
Otto cycle, Heat and Mass Transfer (2011) 47:571–577]
are erroneous and thus the reported results are invalid.
These incorrect relations [Eqs. (8), (9), (10), (14) and (16)
of HO¨ 2011] are replaced by correct ones. Moreover, the
obtained results (graphs and tables) are modified based on
the correct relations. Finally, to achieve more realistic
results, the internal irreversibility described by using the
compression and expansion efficiencies is added to the
analysis.
