Investigation on cavitating flow of a novel high pressure nozzle with grooved needle

摘要

In this paper, a computational study was carried out to investigate the influence of the use of grooved needles on the cavitation flow with needle movement inside a injector nozzle. With this aim, high pressure nozzles with needle movement have been simulated and analysed for 2 different nozzles: one with grooved needle valve and one ordinary nozzle. The internal cavitating flow during the full opening period has been modeled with a multi-hole nozzle model that considers the cavitating flow in thermodynamic and homogeneous equilibrium state. The comparison between two type nozzles has been made in terms of velocity, vorticity, vapor volume fraction and mass flow rate over the needle opening period. The results of the investigation have shown that the groove leads to an increment of the cavitation bubbles of the injector orifice entrance.