Performance Analysis of Four-Stroke Multi-Cylinder Petrol Engine Using Alternate Fuels
Dr.S.Maniraja,A.Anandharajb,T.Dharsanc,M.K.Gokuld,G.Iyppane
Professor, Department of Mechanical Engineering, Paavai Engineering College. UG Scholar, Department of Mechanical Engineering, Paavai Engineering College. UG Scholar, Department of Mechanical Engineering, Paavai Engineering College UG Scholar, Department of Mechanical Engineering, Paavai Engineering College UG Scholar, Department of Mechanical Engineering, Paavai Engineering College
Abstract The progressive exhaustion of conventional fossil-fuel reserves, combined with increasingly stringent emission legislation under Euro 6 and Bharat Stage VI (BS-VI) norms, has created an urgent imperative to develop and validate alternative fuel pathways for spark-ignition (SI) engines. This paper presents a rigorous experimental investigation of the performance and emission characteristics of a four-stroke, four-cylinder water-cooled petrol engine fuelled with four configurations: neat gasoline (baseline), 10% ethanol–gasoline blend (E10), 20% ethanol–gasoline blend (E20), and a compressed natural gas (CNG) pilot blend. Dynamometer tests were conducted at 1500 rpm across four discrete load conditions (25%, 50%, 75%, and 100% of rated load). Measured performance parameters include Brake Thermal Efficiency (BTE), Brake Specific Fuel Consumption (BSFC), Mechanical Efficiency, and Volumetric Efficiency. Exhaust emission constituents—HC, CO, CO₂, and NOₓ—were quantified using a calibrated five-gas analyser in accordance with ISO 8178. The Morse test was used to determine Indicated Power independently for each cylinder. Results demonstrate that E20 achieves the highest BTE of 33.2% at full load, a 10.3% relative improvement over the petrol baseline (30.1%), with BSFC concurrently reduced from 275 g/kWh to 245 g/kWh. HC emissions decrease by 27.6% and CO by 31.6% with E20, while NOₓ rises marginally by 7.2%. CNG blend delivers the lowest CO (1.68% vol) and NOₓ (810 ppm) but at a volumetric efficiency penalty. Uncertainty analysis confirms BTE values within ±1.32% at 95% confidence. E20 is substantiated as a viable drop-in alternative fuel requiring no hardware modification, aligned with India's EBP 2025 mandate.
Index Terms alternate fuels, brake thermal efficiency, BSFC, CNG, ethanol blends, exhaust emissions, four-cylinder engine, SI engine.
