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Recent efforts to reduce emissions of NOx, N2O, and NH3-slip in ammonia-methane (NH3/CH4) combustion using Nanosecond Repetitively Pulsed Discharges (NRPD) have relied largely on complex plasma-assisted combustion experiments in three-dimensional, turbulent, swirl-stabilized burners. In this work, we introduce a modular experimental platform based on a flat-flame McKenna burner to isolate and study the fundamental plasma-flame interactions that govern NRPD-assisted combustion of NH3/CH4/air mixtures. The burner-plasma assembly supports both nanosecond-spark and uniform-discharge operating modes when generating the plasma in the hot exhaust gases. Preliminary NO measurements, with NRPD applied either in the post-flame region or directly within the reaction zone, indicate a net NO penalty under the conditions tested. These results highlight the need for further mechanistic investigation of NRPD-driven chemistry in ammonia-methane flames and its implications for emissions reduction strategies.
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Numerical Study of Nanosecond Pulsed Discharge Effects on Flame Speed and Emissions in Ammonia Flames
Plasma-assisted combustion of ammonia leverages non-equilibrium electrical discharges to modify flame dynamics and emissions. In this work, we perform a numerical investigation using a one-dimensional model to examine the influence of nanosecond-repetitively pulsed discharges on the propagation of stoichiometric ammonia-air flames at atmospheric conditions. The model incorporates detailed plasma chemistry solved with ZDPlasKin. In particular, we look into the influence of pulse repetition frequency on laminar flame speed and NOx emissions. The simulations reveal unexpected behavior in the spatial distribution of plasma energy deposition within the flame. The plasma is found to significantly speed up the flame, up to +140%, although some numerical challenges prevented us from exploring operation at higher frequencies. The chemical kinetics used also predict a small decrease in 𝑁𝑂 in the product region of the flame.
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- Award ID(s):
- 2339518
- PAR ID:
- 10661571
- Publisher / Repository:
- AIAA SCITECH 2025 Forum
- Date Published:
- Format(s):
- Medium: X
- Location:
- https://arc.aiaa.org/doi/abs/10.2514/6.2026-0395
- Sponsoring Org:
- National Science Foundation
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