Development and validation of a new reduced diesel/natural gas mechanism under engine-relevant conditions

A simplified mechanism of diesel/natural gas blend was developed for a dual fuel engine built from a previously reported detailed mechanism of a n-dodecane and natural gas. In the model, n-dodecane was selected as the representative substance of diesel and the mixture of methane, ethane and propane was selected as the representative substance of natural gas. The simplified mechanism was obtained by using the direct relation graph, the directed relation graph with error propagation, and the sensitivity analysis simplification method. On this basis, a simplified n-dodecane-natural gas mechanism with 141 species and 739 reactions was established. In addition, the experimental data and detailed mechanism are used to compare with the n-dodecane-natural gas dual fuel simplified mechanism established in this paper, and have been widely verified in 0-D and 1-D combustion systems for the first time, including ignition delay time, laminar flame velocity, premixed flame species, HCCI combustion, which verify the rationality of the new simplified mechanism. Then the mechanism is coupled to CFD software to simulate the spray combustion of constant volume spray under engine like conditions. The results show that the mechanism has high reliability and can be coupled with CFD.

Automated summary

A simplified mechanism for a dual fuel engine using diesel/natural gas blend was developed based on a previous detailed mechanism of n-dodecane and natural gas. The simplified mechanism was obtained by applying direct relation graph, directed relation graph with error propagation, and sensitivity analysis simplification method. The mechanism was validated through comparison with experimental data and detailed mechanism, and was coupled with CFD software for simulating engine spray combustion.