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The purpose of this study is to investigate the effects of injection timing and injection pressure on combustion characteristics and emissions of the direct injection single cylinder CI engine fueled with ethanol ED95 fuel (95% hydrous ethanol blended with 5% commercial additive by volume) under partially premixed combustion condition. The engine was modified to increase the compression ratio from 18 to 28. The experiment was tested at maximum engine load under a constant engine speed for all testing conditions. The experimental results show a lower coefficient of variation (COV) for the indicated mean effective pressure (IMEP), which implies that higher combustion stability is achieved when the injection timing is advanced. However, the ignition delay significantly increases. In addition, when injection timing is advanced and the injection pressure is increased, THC and CO emissions increase due to lower combustion efficiency.

The purpose of this study is to investigate the startability characteristics of a single cylinder direct injection compression ignition engine fueled with ethanol and blended with ignition improvers. The engine is modified to increase the compression ratio from 18:1 to 23:1 and 28:1. In this study, glycerol ethoxylate and palm oil methyl ester (POME) are considered as the ignition improvers blended with ethanol in various concentrations. Engine speed is used as the key parameter to explain the startability characteristics and categorize them into four types. Type A has excellent engine startability similar to diesel. Type B has good engine startability. Type C has fair engine startability. Engine startability for Type D is unsuccessful. The results show that increasing the concentration of the ignition improver enhances engine startability and reduces the number of misfiring cycles due to improvements in combustion.

Registered vehicles in Thailand, are currently required to pass the European standard (EURO3) driving cycle. Motorcycles comprise the registered vehicles in Thailand, thus it is important to study the exhaust emissions of motorcycles tested with both the European standard driving cycle: Hot emission (EURO3H) and the Bangkok driving cycle. The Bangkok driving cycle has been developed to represent Bangkok traffic. This was a study of gasoline motorcycles with three-way catalytic converters installed to investigate the exhaust emissions using a chassis dynamometer test to compare the EURO3H with the Bangkok driving cycle. The comparison of idle time, velocity and emissions of Carbon Monoxide (CO), Nitrogen Oxide (NOx) and Total Hydrocarbon (THC) for the EURO3H and 6 different phases of the Bangkok driving cycle were investigated.

This work investigates the effects of ignition improvers on the ignition and combustion characteristics of hydrous ethanol with 5% by weight water and 1% by weight Lauric acid (Eh95) under simulated diesel engine conditions using the rapid compression and expansion machine (RCEM). Results indicate that hydrous ethanol with commercial additive (ED95) and hydrous ethanol with 5% by weight glycerol ethoxylate in hydrous ethanol exhibit a near identical rate-of-pressure-rise and heat release rate. Ignition delay of hydrous ethanol with 5% by weight glycerol ethoxylate is shorter, but hydrous ethanol with 1% by weight glycerol ethoxylate has longer ignition delay time and different combustion characteristics compared with hydrous ethanol with commercial additive (ED95). Hydrous ethanol with 1% by weight glycerol ethoxylate and hydrous ethanol with 5% by weight glycerol ethoxylate are considered suitable fuels for high compression-ratio diesel engines.