Influence of Injection Pressure Fluctuations on Cavitation inside a Nozzle Hole at Diesel Engine Conditions 2008-01-0935

The influence of injection pressure fluctuations on cavitation inside a nozzle hole under diesel engine conditions was simulated using a two-fluid model. Injection pressure fluctuations with different amplitudes and frequencies were introduced at the inlet boundary. A comparison of the calculated results with experimental results available in the literatures was performed to verify the model. The simulation results indicate that both partial cavitation and supercavitation are just sensitive to the inlet pressure fluctuations with higher amplitude. As the amplitude decreases, the influence of the pressure fluctuations on cavitation process diminishes and it becomes negligible at the amplitude of around 5%. The frequency of inlet pressure fluctuation has an obvious influence on the inception of cavitation and quasi-periodic behaviors of supercavitation. Moreover, the exit flow structures corresponding to partial cavitation and supercavitation show different responses to the inlet pressure fluctuations.