Numerical study on tri-fuel combustion: Ignition properties of the mixture of methane-hydrogen-diesel fuel

The research on the multi-fuel combustion is of great significance for power machinery especially rocket engines. In this study, the ignition characteristics of tri-fuel (TF) are studied in the aspects of chemical dynamics through sensitivity analysis, rate of production (ROP) analysis and pathway analysis. The role of trace diesel in different CH4/H2 mixtures was researched, especially three components of diesel alternative fuels (NC16H34, IC16H34, A2CH3 (1-methylnaphthalene)) were studied in detail. In addition, the stop changing effect of trace diesel was investigated in the ignition process of TF. The results showed that the increase of pressure reduces the ignition delay times (IDTs) of TF, and it makes the linear relationship between IDTs and temperature stronger at the equivalence ratio of 0.5. Among the diesel alternative fuels in this study, NC16H34 has the greatest influence on ignition through sensitivity analysis, and A2CH3 is the component that has the most complex reaction paths through pathway analysis. In the process of TF ignition, the stop changing effect of trace diesel still exists, and the temperature at which the stop changing occurs rises gradually with the increase of epsilon CH4 and the effect is closely related to reaction NC16H34 + O2 = NC16H33 + HO2. (c) 2022 Elsevier Masson SAS. All rights reserved.

Automated summary

The study investigates the ignition characteristics of tri-fuel and the influence of trace diesel. The results show that an increase in pressure reduces the ignition delay time, NC16H34 has the greatest impact on ignition, and A2CH3 has the most complex reaction pathways. Trace diesel exhibits a stop changing effect during ignition.