Comparative Study on The Effect of Oxygen-Enriched Air on Combustion of a Spark Ignition Engine Fuelled with Methanol and Ethanol

Abstract

An experimental investigation was carried out on a single-cylinder four-stroke spark-ignition engine fuelled fuelled with methanol (M100) and ethanol (E100) to study the effect of oxygen enrichment on combustion characteristics of the engine. The experiments were carried out at base compression ratio 9.8 and the results were compared at higher compression ratio 10.6. The compression ratio was increased by decreasing the clearance volume from the cylinder head. The engine was operated at the maximum torque (4.5 Nm at 3600 rpm) achieved with M100 fuel and the results were compared for both the fuels at the same torque. The results indicate that with oxygen enrichment at the increased compression ratio, in-cylinder peak pressure increased significantly by 34.7% with M100 and 8.4% with E100 compared to base gasoline. The rate of pressure rise increased by 2.7 times with M100 and by 20% with E100. Due to high peak pressure, heat release rate, and rate of pressure rise, the combustion duration decreased significantly with both fuels. The cycle-to-cycle variation in indicated mean effective pressure decreased to 1.48% with E100 and M100. A notable outcome of the study was that the effect of oxygen enrichment was more prominent in methanol combustion than with ethanol at both compression ratios with greater effect at higher CR.

Keywords

• Methanol
• ethanol
• combustion
• IC engine
• oxygen-enriched air

Ethical Statement

This manuscript has not been submitted elsewhere for publication, nor has it been published previously. All authors listed have contributed significantly to the research and preparation of this manuscript. Any potential conflicts of interest have been disclosed.

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