Study On Four Component Surrogate Model And Combustion Reaction Mechanism Of RP-3 Aviation Kerosene

Chemical kinetics mechanism plays an important role in the design and optimization of aero-engine combustion chamber.It is very important for the development and research of aero-engine to explore the chemical reaction process of fuel in aero-engine combustion chamber and construct its micro chemical reaction mechanism.Aviation kerosene is composed of hundreds of hydrocarbons.Aiming at this kind of fuel with complex components,researchers put forward the method of constructing an alternative model,and on this basis,develop the reaction kinetics mechanism to make it show similar chemical characteristics with the actual aviation kerosene.Compared with JP-8 and Jet-A aviation kerosene abroad,there is a lack of research on alternative model mechanism of domestic RP-3 aviation kerosene in a wide temperature range in China.Therefore,it is very important for the design and optimization of aero-engine combustor in China to build an alternative model for domestic RP-3 aviation kerosene and develop reaction kinetics mechanism.Firstly,for RP-3 aviation kerosene with complex components,a four component substitution model including 60%(mole fraction)n-dodecane,10% ndecane,20% methylcyclohexane and 10% 1,2,4-trimethylbenzene was proposed.The model was analyzed from three aspects of molecular weight,functional groups and thermophysical properties,and the accuracy of the alternative model was verified by comparing with the experimental data.Secondly,according to the comprehensive mechanism of oxidation reaction developed by creck modeling laboratory,the detailed mechanism of the four component substitution model is proposed.The detailed mechanism is used to calculate the ignition delay time and flame propagation velocity.The comparison with the experimental data shows that the detailed mechanism has a good ability to predict the macro combustion parameters of RP-3 aviation kerosene.Then,in order to verify the prediction ability of the detailed mechanism of the alternative model built in this paper for the micro parameter component distribution in the cracking and combustion process of RP-3.On the one hand,the supercritical cracking experiment of RP-3 aviation kerosene was carried out.The oil temperature curves and pyrolysis products were measured and collected at different outlet oil temperatures.The gas-liquid ratio,pyrolysis rate and distribution of main components were obtained by analyzing the pyrolysis products,and the prediction ability of the detailed mechanism of the alternative model for supercritical cracking of RP-3 aviation kerosene was verified.On the other hand,the premixed combustion experiments of RP-3 aviation kerosene were carried out to explore the distribution of combustion products at different equivalence ratios(0.5,1.0,1.5)and verify the prediction ability of the model mechanism for RP-3 aviation kerosene combustion.Finally,based on the detailed mechanism of RP-3 aviation kerosene four component substitution model proposed and verified in this paper,the effects of different reaction conditions on the ignition and combustion characteristics of the fuel are explored,and the sensitivity analysis is carried out for the calculated phenomena.In addition,in order to obtain a relatively small semi detailed mechanism,the detailed mechanism is simplified by gdrgep,and a 1580 step semi detailed mechanism with 120 components is obtained.The results are compared with the ignition delay time and laminar flame propagation velocity predicted by detailed mechanism.At the same time,the reaction path of the two mechanisms was analyzed to explore the evolution process of the fuel reaction process and verify the accuracy of the mechanism.