EXPERIMENTAL STUDYING THE EFFECT OF AIR-INJECTION ON THE COMBUSTION BY AN AIR-CELL AND EMISSIONS CHARACTRESTICS IN A DI ENGINE

This research uses an experimental method to explore the effect of air-injection during the late combustion period produced by an air-cell on the combustion and emissions in directinjection diesel engine. In this work which is done at Motorsazan (Iran tractor manufacturing company), the engine considered is a 135TI test engine which was modeled with an air-cellincluded as part of the piston geometry. Pollutant emission and combustion characteristicsmeasurements were performed according to the (ECE-R96) for baseline and modified engines. The comparing of the results shows that the emissions of the modified DI diesel engine are improved than the baseline engine while bsfc is remaining almost the same. In this study, a moreimprovement in particulates was obtained, while reducing of NOx by the mean of 5.4 percent, by the using of air-cells for injecting air into the combustion chamber to augment mixing and thereby increasing the rate of soot oxidation.