Computational study of induced in nozzle cavitation and its effects on nozzle flow for a heavy duty diesel engine

For the combustion process to be controlled inside a heavy duty diesel engine, fuel atomization is thought to be the best tool. Engine efficiency and emissions reduction can only be controlled by controlling combustion. Atomization of fuel or breaking down the fuel into tiny droplets to increase the surface area which will result in for complete combustion. This occurs due the cavitation effect occurring inside the injector nozzle. Cavitation can be said to be one of the most important factor in the combustion process due to the fact that it has a strong effect on the nature of the spray injecting into the chamber. The phenomenon will lead to complete combustion process where as if the fuel will is not burnt completely, the unburnt hydrocarbon will pollute the atmosphere moreover the efficiency of the engine will be compromised which is indeed not desired. In diesel injectors the main role of atomization can be observed due to cavitation and the flow behaviour is significantly affected by the cavitation. Cavitation affect will determine the flow entering into the combustion chamber for combustion. The problem to limit the study of fuel injectors is that the fuel injectors are very small and they are operated at very high pressure. This study carried out will help us in better understanding of cavitation process occurring and the effects of cavitation on the flow. Different types of nozzles were studied. These parametric study will help us to develop better injectors in future and can improve engine efficiency. The process of cavitation has strong effects on different parameters of the flow which include mass flux, momentum flux, and the velocity of the flow entering into the chamber. Different geometries were modelled on Solid works and were imported in Ansys for simulating the effects of cavitation. Results obtained by a wide range of simulations can be analysed for better engine performance and low emission.