Mixture formation plays
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INTRODUCTION

Mixture formation plays as a key element on burning process that strongly affects the exhaust emissions such as nitrogen oxide (NOx) and Particulate Matter (PM). The reductions of emissions can be achieved with improvement throughout the mixing of fuel and air behavior.

In diesel engines, combustion progresses by nature heterogeneous. Diesel spray spontaneous ignites within short period after fuel injection. The diesel engine has undergone continues improvements through the development of engines technologies especially in controlling the combustion process in order to reduce the NOx and PM levels and also to tackle the fuel economy vehicle. The most important issue in diesel combustion is achieving sufficient rapid mixing between the injected fuel and the air in cylinder prior to ignition. In this research, the new combustion concept based on the characteristics of diesel ignition and combustion is investigated focusing on fuel-air mixing with changing ambient condition.

The oxidation reactions at the end of endothermic period depend on the physical process such as air entrainment, the breakup of the jet spray, and droplets evaporation. Along with these parameters, a better comprehension of combustible mixtured, auto-ignition and combustion process is also needed for the optimization of diesel engines.