Numerical analysis of the momentum and heat transfer in an atmospheric pressure dielectric barrier discharge

In this paper, the momentum and heat transfer between charged particles and neutral particles in a needle-to-plane dielectric barrier discharge reactor with Ar as the working gas are simulated. In this simulation, the heat transfer from ions to the neutral atom is described by the interaction term between ions and atoms. Detailed discharge reaction mechanisms are considered in the simulation including metastable atom. The Navier-Stokes equation is solved in combination with the Poisson equation and the charged particles drift-diffusion equations. The interrelation between the gas discharge and the gas flow characteristics are preliminary revealed. In particular, when the streamer strikes the cathode, the maximum gas temperature can reach 1026 K, and the high temperature area is concentrated in a confined space around the needle cathode tip with a thickness of 0.01 mm and a diameter of 0.1 mm. Then, the temperature change decreases to 400 K in 1 μs. Induced by the discharge, the pressure perturbation of the gas can exceed 6×104 Pa at 1.1 μs, and an expanding wave is created. The propagation velocity of the expanding wave is close to the sound velocity. The forward velocity decreases from approximately 120 m/s at 1.1 μs to 5.5 m/s at 4.4 μs. The inverted velocity remains at approximately 5 m/s. The number density for the neutral particles has a minimum value, which is approximately 8×1024 m-3, in the sheath as well as changes in the expanding wave propagation in the plasma bulk.