Abstract
Abstract: Petroleum resources are finite and therefore search for alternative fuel is continuing all over the world. The rising prices of petroleum fuels, dwindling oil reserves and stringent regulations for exhaust emissions have necessitated the substitution of fossil fuels with less polluting and easily available renewable fuels for internal combustion engines. The application of ethanol as a supplementary fuel will reduce environmental pollution, strengthen agricultural economy, create job opportunities, reduces petroleum fuel requirements and thus contributes in conserving a major commercial energy source. At present ethanol has been recognized as a quality engine fuel for the spark ignition engine because of its high octane number and better performance in terms of power and efficiency and it has cleaner burning characteristics. The proposed paper presents the results of experimental research carried on the IT 9- 2M octane number engine, when the engine is fuelled with ethanol-gasoline blends at different proportions in order to establish the gasoline-ethanol blend knock behaviour and flame propagation velocity. The experimental research carried on the IT 9-2M engine, using gasoline-ethanol blends in different proportions presents the following aspects: the average flame velocity increases for blends with high ethanol content; the NOx emission level decreases when using gasoline - ethanol blends; the CO emission decreases in case of fuelling with gasoline-ethanol blends for leaner dosages; when the ethanol content increases, the fuel antiknock quality improves.
Keywords: ethanol, knock, ionisation plug, compression ration, octane number, SI engine