Non-Equilibrium Plasma Ignition Studies for Enhanced Reactivity

Transitioning to sustainable energy fuels is critical for mitigating climate change, ensuring energy security and meeting future energy demands. However, operability issues regarding low flames speeds, unstable flames, narrow flammability limits, and long ignition delays are potential obstacles that have hindered their widespread adoption into practical systems. Non-equilibrium plasmas (NEP) have been shown to promote energy-efficient chemical reactivity through quenching and transport of electronically excited atoms and molecules, selective radical production, and fast gas heating. In the present work, on-going efforts are discussed to demonstrate the efficacy of NEP as an enabling technology to improve the operability characteristics of combustion devices. Demonstrating NEP-assisted ignition at elevated pressures remains a challenge, but rapid compression machine experiments and novel plasma igniter designs are being explored to evaluate ignition performance. Preliminary results demonstrate pulsed plasma ignition can enhance burn rates compared to conventional spark ignition technologies. Transitions from pulsed spark to glow discharge appear to influence flame kernel development and modify reaction kinetics, contributing to improved ignition behavior. Derived insights are expected to facilitate the optimization of plasma-based technologies for next generation power and propulsion applications.