Effect of viscosity, temperature and nozzle length-to-diameter ratio on internal flow and cavitation in a multi-hole injector

Abstract

Two 3-D six-hole transparent enlarged model injector have been manufactured with full optical access; both were 15 times larger than the real size, but one had a length-to-diameter ratio twice as the second one. The working fluid was water and aqueous solutions of glycerol circulating through the nozzle injector under steady- state flow conditions at different flow rates, pressures and needle lift positions. Real-time in-nozzle flow visualisations were obtained using a high speed video recorder which allowed determination of in-nozzle flow patterns, in particular, formation, dynamics and the development of cavitation.