The spray of micro injection was simulated by CFD. Meanwhile

parameter optimization of a spray breakup model for diesel micro injection spray was mainly studied

and the parameter optimization law of the spray breakup model was obtained. Compared with the CFD simulation of traditional spray

the size and time parameters of first and second breakup models for micro spray CFD simulation should be decreased

and the adjustments of time and size parameters for first and second breakup models are based on the inflection point of penetration curve

which could be used for accurate numerical simulation of diesel micro injection spray in the conditions of different injection quantity.