Two-dimensional simulation of nanosecond surface dielectric barrier discharge-assisted ignition in premixed H2/air mixtures

Nanosecond surface dielectric barrier discharge (nSDBD) is a promising approach for plasma-assisted ignition. In this work, a two-dimensional coupled plasma–combustion model is developed to study nSDBD-assisted ignition in a premixed stoichiometric H2/air mixture at atmospheric pressure with an initial temperature of 800 K. The simulations show that a negative surface streamer propagates along the dielectric surface, forming a radical-rich layer mainly composed of O, H, and OH, together with a localized thermal layer near the high-voltage electrode. During the afterglow, ignition first occurs near the electrode edge and then develops into an expanding flame kernel. The flame initially spreads faster along the dielectric surface and later transitions to self-sustained propagation into the unburned mixture. Additional calculations with separated thermal-only and kinetic-only initial conditions show that under the present operating conditions, the plasma-generated radical pool plays a leading role in ignition initiation, while gas heating mainly accelerates subsequent flame-kernel development.