Title: Performance and emissions of motorcycle engines using water-fuel emulsions

Authors: Yuh-Yih Wu, Bo-Chiuan Chen, Jen-Jyh Hwang, Chung-Ying Chen

Addresses: Department of Vehicle Engineering, National Taipei University of Technology, No 1, Sec 3, Jhongsiao E. Rd., Taipei 10608, Taiwan, ROC. ' Department of Vehicle Engineering, National Taipei University of Technology, No 1, Sec 3, Jhongsiao E. Rd., Taipei 10608, Taiwan, ROC. ' Department of Mechanical and Electro-Mechanical Engineering, National Sun Yat-sen University, Kaohsiung, No 70, Lienhai. Rd., Kaohsiung 80424, Taiwan, ROC. ' Department of Mechanical and Electro-Mechanical Engineering, National Sun Yat-sen University, Kaohsiung, No 70, Lienhai. Rd., Kaohsiung 80424, Taiwan, ROC

Abstract: This article studied water–gasoline emulsions for reducing the NO_x emissions of a motorcycle engine. Emulsified gasoline fuels of 0, 5, 10 and 15% water by volume were used in a four-stroke, 125 cc, port injection, spark-ignition engine. Both full throttle speed ranging from 2,000 to 7,000 rpm and low load were tested. The engine torque, fuel consumption, exhaust emissions and combustion characteristics were investigated. The experimental results show that the engine torque and fuel consumption are improved for 5 and 10% water emulsions. However, at 15%, the engine torque and fuel consumption deteriorate and the exhaust temperature is increased owing to slow burn rate. The exhaust emissions of NO_x and CO decrease as the water percentage in the emulsion increases. A higher oxygen concentration in exhaust gas of emulsified fuel was found, which results in lower CO emission. The HC emission is increased with increasing water content, which might be caused by the thicker quench layer of emulsified fuel combustion. An appropriate concentration of water in the emulsified gasoline fuel for a 125 cc motorcycle engine is found to be 10%.

Keywords: heat release rate; motorcycle engines; SI engines; spark ignition engines; water–gasoline emulsion; motorbikes; engine performance; engine torque; fuel consumption; exhaust emissions; combustion characteristics.

DOI: 10.1504/IJVD.2009.024242

International Journal of Vehicle Design, 2009 Vol.49 No.1/2/3, pp.91 - 110

Published online: 30 Mar 2009 *

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