Construction of NTO/UDMH combustion mechanism and analysis of ignition characteristics
To improve the CFD numerical calculation accuracy of the combustion of hypergolic propellant liquid rocket engines,a detailed combustion mechanism of nitrogen tetroxide(NTO)/unsymmetrical dimethylhydrazine(UDMH)with 63 components 357 elementary reactions was constructed based on the hierarchical method.The detailed mechanism was simplified using a single simplification method and a combination of multiple simplification methods,resulting in 35 components 149 elementary reactions and 23 components 19 elementary reactions that were in good agreement with the detailed mechanism.Based on this,the influence of different pressures,temperatures,and the ratios of oxygen and fuel on the ignition characteristics of the detailed mechanism and simplified mechanism was studied.Increasing the initial pressure will integrally increase equilibrium temperature and ignition delay time of the system.And the higher initial pressure leads to the slower the system equilibrium temperature increment:decreasing from 1 035-1 320 K/MPa to 170-320 K/MPa.Meanwhile,the increase in initial temperature will increase the equilibrium temperature of the system but shorten the ignition delay time.When the initial temperature increases by 1 K,the equilibrium temperature of the system will increase by about 3 K.The growth of the oxygen fuel ratio will lower the system equilibrium temperature and raise the ignition delay time.Larger oxygen fuel ratio results in a rapid increase in ignition delay time.The law provides an important reference and theoretical basis for the study of NTO/UDMH reaction kinetics.The detailed and simplified mechanism constructed helps to establish a more accurate simulation model of engine combustion flow field.
unsymmetrical dimethyl hydrazinenitrogen tetroxideconstruction of reaction mechanismsimplify the mechanism
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维普
