Construction And Verification Of Quasi-one-dimensional Simulation Platform For Plasma Assisted Combustion

Plasma-assisted combustion plays a very important role in rapidly heating gases,reducing ignition delay time,improving flame stability,broadening the combustion limit,increasing flame propagation rate,and reducing pollutant emissions for ignition and combustion enhancement.Researchers at home and abroad have demonstrated the effectiveness of plasma-enhanced combustion characteristics from phenomena,but the specific enhancement mechanism remains unclear.In order to understand the inherent mechanism between plasma effect and combustion,researchers have made great efforts in developing new experimental platforms,advanced diagnostic methods,quantitative experimental databases and dynamic models.However,since the plasma discharge time(in ns)is much shorter than the typical combustion time(in ms),the establishment of a plasma enhanced combustion kinetic model still presents significant challenges.This paper mainly establishes a plasma combustion combustion calculation platform with wide applicability based on the existing calculation models in the laboratory.And the experimental platform was built in coordination,and the accuracy of the platform was verified by experimental data.The main contents are as follows:(1)A plasma is established by coupling a set of ordinary differential equations describing the density of different substances(neutral groups,excited states and charged particles,etc.),the energy equation for predicting the temperature of the mixture,the Boltzmann equation,and the quasi-one-dimensional flow equation.Body combustion platform.The material concentration equation is coupled with the steady-state binomial expansion of the Boltzmann equation to calculate the plasma electron energy distribution function(EEDF).Taking the experimental cross section as the input parameter,the Boltzmann equation solver iteratively solves the EEDF,and obtains the rate constants of the electron collision excitation,dissociation and ionization processes.The hard equation solver(LSODE)is then used to solve the above equations,and the change in the concentration of the material along the flow direction of the reactor with the reaction is calculated by the combination of plasma and thermochemical kinetics.(2)Coordinated the construction of a nanosecond pulse discharge assisted methane cracking/oxidation experimental platform,designed a flow reactor suitable for plasma dynamics model calculation,and carried out experiments.(3)By searching the literature to collect the kinetic mechanism of plasma-assisted methane cleavage,the kinetic effect of nanosecond pulse DBD discharge on methane cleavage was studied using the plasma combustion-supporting platform.Firstly,the energy of the reaction process,the field strength,the concentration of the components and the reaction path were studied.Then the accuracy of the calculation platform was verified by comparing the experimental data.The effects of different initial temperature,discharge voltage and repetition frequency on the cracking process of CH4 were studied.(4)Based on the plasma combustion-supporting platform constructed in this paper,the kinetics of methane oxidation under nanosecond pulse DBD discharge was studied.Firstly,the kinetics of plasma-assisted methane oxidation under a single working condition was studied and analyzed.The effects of initial temperature,discharge voltage and repetition frequency on methane oxidation process were studied by comparing the experimental data,which further verified the accuracy of the calculation platform.