A skeletal mechanism with 133 species and 877 reactions for MOD9D (one of the main unsaturated methyl esters in biodiesel fuels) is constructed by using decoupling methodology. The obtained skeletal mechanism consists of four parts: high temperature decomposition, low temperature oxidation, ester group reactions and detailed chemistry of small species. Extensive validations are firstly performed against available experimental data in shock-tube for autoignition delay. The predicted results by the skeletal mechanism matches well with the experiment results. The comparison has been conducted between the detailed mechanism and a semi-detailed mechanism. Good agreement or even better predictions at some initial conditions has been observed. Further validations are conducted against the experimental data of fuel species’ conversion rate and species concentration in PSR at varying initial temperatures. The results indicate that the developed skeletal mechanism is capable of predicting the combustion characteristics of MOD9D.
Keywords biodiesel, unsaturated methyl esters, mechanism reduction, decoupling methodology