Performance of diesel engine using gas mixture with variable specific heats model

Abstract

Abstract A thermodynamic, one-zone, zero-dimensional computational model for a diesel engine is established in which a working fluid consisting of various gas mixtures has been implemented. The results were compared to those which use air as the working fluid with variable specific heats. Most of the parameters that are important for compression ignition engines, such as equivalence ratio, engine speed, maximum temperature, gas pressure, brake mean effective pressure and cycle thermal efficiency, have been studied. Furthermore, the effect of boost pressure was studied using both the gas mixture and dependent temperature air models. It was found that the temperature dependent air model overestimates the maximum temperature and cylinder pressure. For example, for the air model, the maximum temperature and cylinder pressure were about 1775 K and 93·5 bar respectively at 2500 rev min−1, and the fuel/air equivalence ratio Φ = 0·6. On the other hand, when the gas mixture model is used under the same con...