Technical Paper
Flame structure characteristics and performance comparison of a NG SI engine under stoichiometric and lean combustion using CFD
2024-01-08
2023-36-0120
The development and improvement of efficient compressed natural gas (CNG) engines align with efforts to reduce greenhouse gas and pollutant emissions. The objective of this study is to evaluate the flame structure and compare the performance characteristics of an engine powered by compressed natural gas (CNG) under stoichiometric and lean combustion in wide open throttle. CFD simulation alongside experimental tests are performed. The experimental data were obtained using a Hyundai 2.5-liter HR engine, originally a Diesel engine, adapted for spark ignition operation. Lean and stoichiometric conditions were evaluated at compression ratio 14:1, operating at 1800 rpm in MBT spark timing. The results showed that increasing lambda (λ) had a significant effect on apparent heat release rate, laminar flame speed, flame thickness and flame surface area.
