Effects of nozzle geometry and fuel characteristics on cavitation phenomena in injection nozzles

Effects of nozzle geometry and fuel characteristics on cavitation phenomena in injection nozzles

Atomization is greatly affected by the cavitation occurring inside diesel fuel injector nozzles, and simulating this phenomenon will be helpful in future injector development. Among three different cavitation model that are available in Ansys Fluent v14, singhal et al. cavitation model have been chosen since this model is capable of predicting choke condition in cavitating flow accurately. This model assumes the two-phase flow inside a nozzle in homogeneous mixture of vapor, liquid and noncondensable gas. The pressure profile and the velocity profile obtained from the simulations were compared with the experimental results of planar throttle flow. In this paper the effect of nozzle contraction illustrated in nozzle and it was shown that as contraction increases the pressure at nozzle entrance will increase and critical cavitation condition will occur in different situation. Inlet radius and surface tension also have been explained, and inlet radius can affect cavitation formation and cavitation region significantly but surface tension is not a parameter that influence cavitation phenomena and atomization process greatly.