The effects of equivalence ratio, pressure, and temperature on nanosecond surface dielectric barrier discharge ignition for ammonia/air mixtures

Multi-point ignition and non-equilibrium plasma ignition technologies were both certified to enhance the ignition and combustion processes of ammonia (NH 3 ). High-frequency Nanosecond Surface dielectric barrier discharge (nSDBD) ignition is a promising strategy to carry out both multi-point ignition and non-equilibrium plasma ignition with high energy supply. However, there is little research on how equivalence ratio, initial pressure, and initial temperature affect NH 3 /air mixtures ignited by nSDBD in Constant Volume Chamber (CVC). This study experimentally-investigated the plasma assisted NH 3 /air ignition with a high-frequency nSDBD device in a CVC. The effects of equivalence ratio, initial pressure, and initial temperature on this plasma assisted NH 3 /air ignition strategy were evaluated by discharge performance, flame morphology, and combustion parameters. Results showed that initial pressure strongly influenced the total supplied energy to nSDBD, with a bell-shaped tendency as the initial pressure increased. Near-stoichiometric mixtures exhibited the fastest flame kernel development, the highest pressure rise, and the greatest heat release. Lower initial pressure and higher initial temperature generally promoted flame kernel growth but delayed pressure rise and heat release, though extremely low pressure prevented ignition. • Nanosecond-scale high-frequency nSDBD was applied to ignite NH 3 /air mixtures. • Effects of equivalence ratio, initial pressure, and initial temperature on NH 3 ignition. • Near stoichiometric equivalence ratios achieved optimal combustion. • Increasing initial temperature promoted NH 3 ignition and combustion.