Development of a plasma-coupled rapid compression machine to study advanced ignition concepts

Area of Science:

• Combustion science
• Plasma physics
• Chemical engineering

Background:

• Next-generation combustion devices require innovative ignition strategies for emerging fuels under near-limit conditions.
• Existing experimental platforms have limitations in studying ignition phenomena at extreme regimes.

Purpose of the Study:

• To develop and validate a novel modular plasma-coupled rapid compression machine (PRCM) for comprehensive ignition studies.
• To investigate the effects of non-equilibrium plasmas on fuel reactivity and combustion processes.

Main Methods:

• Designed a modular, mono-piston, single-stroke PRCM capable of pressures up to 70 bar and temperatures up to 1200 K.
• Utilized a high-voltage pulse generator for kilohertz repetitive nanosecond pulsed (KRNP) discharges.
• Integrated high-speed pressure transducers and optical access for time-resolved diagnostics.

Main Results:

• PRCM validated against literature auto-ignition data for methane and n-butane mixtures.
• Preliminary KRNP studies at 10 bar demonstrated a ~20% increase in burn rate for n-butane compared to conventional spark ignition.
• Observed significant plasma-combustion coupling effects on ignition delay and burn rate.

Conclusions:

• The PRCM is a versatile and high-fidelity platform for fundamental combustion research.
• Non-equilibrium plasma-assisted ignition, particularly KRNP, effectively enhances fuel reactivity and combustion kernel development.
• Findings will guide the design of optimized plasma-based ignition strategies for advanced propulsion and power systems.