Influences of Compression Ratio on Performance of Single Cylinder Otto Engine Using E50 Fuel

Abstract

Ethanol mixed with a primary fuel is a promising alternative fuel. To increase performance, an optimal compression ratio must be set. The compression ratio is the ratio of the maximum volume divided by the minimum volume. Ethanol-gasoline mixtures have high octane and can be used in high-compression engines. This research aims to identify how changes in compression ratio can affect various aspects of engine performance, including torque, power, fuel efficiency, and thermal efficiency. This study is expected to reveal new insights that can aid in optimizing engine performance and developing a more comprehensive understanding of the characteristics of the E50 fuel within the context of Otto engine usage. A single-cylinder Otto engine was used for testing. Compression ratios of 9.3:1, 10.3:1, and 11.3:1 were tested. The results showed that the compression ratio of 9.3:1 produces a peak torque of 7.17 N∙m, peak power of 3.36 kW, lowest BSFC of 0.275 kg/kWh, and highest BTE of 37.49%. A compression ratio of 10.3:1 produces a peak torque of 7.21 N∙m, peak power of 3.57 N∙m, lowest BSFC of 0.281 kg/kWh, and highest BTE of 39.46%. A compression ratio of 11.3:1 produces a peak torque of 7.73 N∙m, peak power of 3.81 kW, lowest BSFC of 0.275 kg/kWh, and highest BTE of 40.36%. Compared with pertalite, E50 reduces torque by 9.25%, power by 9.93%, BSFC by 3.66%, and BTE by 8.76% at all compression ratios.