Abstract
This paper describes the atomization characteristics of common-rail diesel injector using the KH-DDB hybrid breakup model. The KH-DDB hybrid breakup model assumes that the breakup within the breakup length is happened by the result of the competition between the Kelvin-Helmholtz instability of KH model and droplet deformation of DDB model. On the other hand, the DDB model is used to predict the breakup of droplet beyond the breakup length. The predicted results such as the images of spray development and SMD distribution are obtained by using the KH-DDB hybrid breakup model at the injection pressures of 60MPa and 80MPa. To verify the prediction accuracy of the hybrid model, the experiments on the atomization of common-rail diesel injector are conducted by using a PDPA system and spray visualization system, and the experimental results are compared with the predicted results.
It is revealed that the prediction accuracy of KH-DDB hybrid model is improved comparing with the results of original breakup model of KIVA-3 code.