What type of study is this?

This is a Experimental Study study.

September 23, 2025

Coupled plasma–flow interaction in moderate or intense low-oxygen dilution combustion: Insights from a phenomenological force model

Key Points

Plasma enhances combustion by increasing velocity through ionic forces by ∼ 2 m/s, benefiting flame stability and efficiency.
The Suzen–Huang model was validated against experimental data, leading to insights on temperature increases of approximately 200 K due to plasma.
Enhanced mixing along the central burner axis accelerated fuel consumption and improved reaction rates, significantly reducing CO emissions.
Plasma's impact on the nozzle velocity field emphasizes the need for accurate modeling of electrohydrodynamic interactions in combustion.

Abstract

Plasma-assisted combustion has garnered significant interest due to its potential to enhance engine performance, improve flame stability, increase fuel efficiency, and reduce hydrocarbon emissions. This study addresses the dynamic effects of plasma in a MILD (Moderate or Intense Low-oxygen Dilution) combustion environment using the Suzen–Huang model, departing from conventional approaches that often predefine plasma effects or rely on simplified boundary values. After implementing the Suzen–Huang model in the form of a user-defined function code and validating its performance using the results and geometry of Suzen–Huang and another experimental work, this model was validated against experimental data from Wada et al. and subsequently used to investigate the impact of plasma on velocity fields, temperature fields, combustion behavior, flame characteristics, and CO pollutant production. The findings reveal that plasma enhances combustion by providing a non-uniform velocity profile at nozzle with acceleration near the electrode, increasing velocity through ionic forces by ∼ 2 m/s, and promoting better mixing via vortex generation in the plasma discharge region. Despite the diluted oxygen conditions of MILD combustion, plasma increased temperatures by approximately 200 K, indicating greater heat release. Enhanced mixing was observed along the central burner axis, leading to faster fuel consumption and improved reaction rates. Additionally, plasma reduced the flame length and lift-off length by altering the distribution of OH species, while significantly decreasing CO pollutant production. An increase in oxygen concentration (from 6% to 12%) in the plasma reactor intensified OH and CO species production but reduced their spatial extent, indicating localized enhancement of combustion reactions. The observed modifications to the nozzle velocity field caused by plasma discharging highlight the critical importance of accurately modeling the force effects of plasma in combustion environments. Conventional approaches that overlook these electrohydrodynamic interactions fail to capture the essential physics governing plasma-enhanced combustion.

Demander à l'IA

Bookmark