• Mr. Vijay C Patel
• Mr. Piyush L Bhogayata

Natural gas, owing to its high octane rating and low carbon-to-hydrogen ratio, is a promising alternative fuel for spark-ignition (SI) engines. However, combustion stability and exhaust emissions are strongly dependent on the air–fuel (A/F) ratio. This work investigates the influence of A/F ratio on cyclic variation and emissions of a single-cylinder natural gas SI engine. Experiments were carried out at varying equivalence ratios (λ = 0.8–1.6). The results showed that stoichiometric conditions (λ ≈ 1.0) provide stable combustion with moderate emissions, whereas lean mixtures (λ > 1.3) significantly reduce NOx but increase unburned hydrocarbons (HC) and cyclic variability. Rich mixtures (λ < 1.0) increase CO and HC emissions. The study demonstrates the importance of optimizing the A/F ratio for achieving stable and environmentally sustainable engine operation.

Natural Gas Engine, Air-Fuel Ratio, Cyclic Variation, Spark-Ignition Engine Emissions, Lean Burn Combustion, Equivalence Ratio.

"Importance of Optimizing Of Air–Fuel Ratio on Cyclic Variation and Exhaust Emissions in A Natural Gas Spark-Ignition Engine", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.8, Issue 12, page no.g53-g56, December-2021, Available :http://www.jetir.org/papers/JETIR2112605.pdf

"Importance of Optimizing Of Air–Fuel Ratio on Cyclic Variation and Exhaust Emissions in A Natural Gas Spark-Ignition Engine", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.8, Issue 12, page no. ppg53-g56, December-2021, Available at : http://www.jetir.org/papers/JETIR2112605.pdf