CFD analysis of combustion on direct injection diesel engine with two different piston bowl configurations

Direct injection diesel engines have served in both light duty and heavy duty vehicles because of higher thermal efficiency compared to SI engines. However, due to the short duration of fuel-air mixing time, combustion process is quite affected. As a result, DI Diesel engine emits more Nox and soot emissions into the atmosphere. Therefore to achieve better combustion with less emission in such engines to accelerate the fuel-air mixing to improve the combustion is by designing of proper combustion chamber. Hence an attempt has been made to study the effect of combustion chamber configuration on Diesel combustion with two different piston bowls through CFD analysis. The two different piston configurations considered in this study are centre bowl on flat piston and pentroof offset bowl piston. From this CFD analysis, combustion pressure, heat release rate, flame structure, fuel injection on flow field, spray structure, droplet diameter, droplet velocity, Nox and soot emissions has been studied and the best piston configuration has arrived. As combustion studies could not be validated, the flow field studies are validated.