Investigating the effect of the heat transfer correlation on the predictability of a multi-zone combustion model of a hydrogen-fuelled spark ignition engine

Abstract

Research on the heat transfer in hydrogen-fuelled spark ignition engines indicates that the two most common heat transfer correlations, namely the Annand correlation and the Woschni correlation, cannot perfectly predict the heat flux during the engine cycle. This questions the accuracy of thermodynamic hydrogen engine models because the heat transfer is one of the important submodels in the development of a thermodynamic model. In addition, the Hohenberg correlation and the Shudo–Suzuki correlation have not been evaluated for hydrogen engines. In this study, a thermodynamic model of the closed cycle of a spark ignition engine is developed with a multi-zone combustion submodel to predict the pressure and the heat flux traces and to compare the predicted values with the available experimental results. The effects of implementing different heat transfer correlations in the prediction of the maximum pressure of the cycle, the total heat transfer and the work are presented for two different compression ratios and two equivalence ratios with different ignition timings. The results indicated that, although the implemented heat transfer correlations predicted the heat flux and the heat transfer with a large percentage error, the fractal-based combustion model implementing the Annand correlation and the Shudo–Suzuki correlations predicted the maximum pressure and the total work with less than 10% error. Finally, a modified version of the Hohenberg correlation for predicting the total heat transfer in a hydrogen spark ignition engine was presented.