ANALYSIS OF DIESEL ENGINE OPERATION

In this paper is presented a method for both combustion irreversibility and working medium availability computations, in a diesel engine. The results of the second-law analysis of engine operation with dodecane (C12H26) fuel are compared with the results of a similar analysis for cases where a light, gaseous (CH4) and an oxygenated (CH3OH) fuel is used. It is shown theoretically that the decomposition of lighter molecules leads to less entropy generation compared to heavier fuels. This is verified computationally for the particular fuels and the corresponding decrease in combustion irreversibility is calculated. Special reference is made to the effect of the lower mixing entropy of the exhaust gas of an oxygenated fuel (CH3OH) as a contribution to the discussion of the advantages and disadvantages of the use of such fuels.