| Summary: | 碩士 === 國立交通大學 === 機械工程系所 === 97 === A simulation of low temperature nitrogen dielectric barrier discharge (DBD) at atmosphere pressure is proposed in this thesis. The parallelized fluid modeling is used to simulate the pure nitrogen discharge. All of the model equations are discretized using fully coupled Newton-Krylov-Schwarz algorithm, in which the preconditioner and linear matrix solver are overlapping additive Schwarz method and Bi-CGStb/GMRES scheme.
The transport coefficients of nitrogen plasma and chemical reaction rate are obtained from BOLSIG, which is a Boltzmann solver can evaluate electron energy distribution function by the user given cross sections. A chemistry module take care the reactions in fluid modeling, in which pure nitrogen chemistry in this thesis include 8 species, N2, N2(A3), N2(B3), N2(C3), N2(a’1), N2+, N4+ and electron. 30 reaction channels are considered which include excitation, ionization and recombination reactions.
The total currents of simulation and experiment are compared, and it reveals that the simulation result is corresponding to the experiment data. The power absorption is evaluated, and it shows that the absorbed power of ions is higher than the electron. According to the number densities of electron and positive ions simulated, it shows that the discharge is Townsend-like discharge. Furthermore, the influence of different dielectric permittivity and different discharge gap are discussed.
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