The effect of the initial charge temperature under various injection timings on the second law terms in a direct injection SI hydrogen engine

In this study, the effect of the initial charge temperature on the second law terms under the various injection timings in a direct injection spark ignition hydrogen fuelled engine has been performed theoretically during compression, combustion and expansion processes of the engine cycle. The first law analysis is done by using the results of a three dimensional CFD code. The results show a good agreement with the experimental data. Also for the second law analysis, a developed in house computational code is applied. The results reveal that the indicated work availability is more affected by varying hydrogen injection timing in comparison with other second law terms. Also increasing the initial charge temperature causes the heat loss availability and exhaust gas availability be increased and indicated work availability, combustion irreversibility and entropy generation be decreased.