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The capabilities of various numerical models to accurately account for the onset and development of cavitation in diesel injector nozzles is assessed and evaluated. The numerical predictions of the models are computed, and are compared to measured experimental data and observations. The numerical predictions for actual diesel nozzle geometry have been validated with experimental measurements of the total vapor mass flow rate. This vapor flow is found to be developed along the nozzle length due to the nucleation of the cavitation bubbles inside the diesel injector. The cavitation inception criteria that is used for the quantitative cavitation calculations included vapor quality, voidage, cavitation kinetic energy and cavitation energy. The results indicate that the cavitation simulation model predicts a diffused and gradual vapor distribution inside the nozzle in agreement with the experimental data.

In recent years, entirely combined CFD-Multi-Zone chemistry combustion models have been developed fashionably in investigating the HCCI engine combustion. In this work, an enhanced Multi-zone chemistry model is recommended for the HCCI engine combustion and emission simulation. There are four sorts of zones enclosing the crevice zone; boundary layer zone, external zones and center zone of the engine cylinder have been applied. The volume of each zone is steady and depends on the engine geometry. The boundary layer zone is the closest zone to the engine cylinder wall. In this study, the reduced chemical kinetic oxidation mechanism of diesel/biodiesel-ethanol has been numerically investigated in homogenous charge compression ignition (HCCI) engine. The oxidation mechanism of the diesel oil-biodiesel-ethanol at different blends was developed and coupled with Multi-Zone chemical kinetics model.