Approximate ecological efficiency with a non-linear heat transfer

The optimisation of a thermal engine performing a Carnot type cycle is considered under the criterion that it should produce high power output with the least possible entropy production in the cycle. It is assumed that the heat transfer between the reservoirs and the engine takes place according to the Dulong and Petit heat transfer law. Also an expression was found for the efficiency as a power series in a parameter that is a function of the compression ratio. It was also shown that this result reduces itself to the ecological efficiency calculated without taking explicitly into account the time of the adiabatic processes.