Drift-Diffusion Modeling of Non-equilibrium Plasma Streamers with Photoionization

Non-equilibrium plasma streamers play a critical role in nanosecond pulsed discharges, plasma-assisted combustion enhancement, and plasma-based flow control, yet their accurate modeling requires a self-consistent treatment of electrodynamics, transport, and plasma chemistry. In this work, we present a drift-diffusion-convection framework for simulating plasma streamer propagation at atmospheric or higher pressures interacting with gas flows. An in-house OpenFOAM-based solver is developed from a reacting flow framework (originally for combustion simulation) to incorporate charged species equations, electron energy equation, Poisson’s equation of electrostatic potential, and photoionization models. The governing equations couple the compressible Navier–Stokes system with reacting multi-species transport, total enthalpy conservation, and plasma-specific source terms, while electron-impact kinetics and electron transport coefficients are evaluated using pre-tabulated rate coefficients generated by BOLSIG+. The resulting solver provides a self-consistent description of plasma streamer dynamics with photoionization, capturing the distortion of background electric fields by space�charge effects and the subsequent front propagation. Numerical demonstrations include a negative (anode-directed) streamer in nitrogen, streamer propagation with photoionization, and nanosecond repetitively pulsed (NRP) discharges in air, highlighting the predictive capability of the extended framework for plasma streamer evolution.