Abstract: For the serious phenomenon of the traditional nozzle spray run into a wall and the spray interference of general porous nozzle under high injection pressure, this paper designed a staggered arranged porous nozzle with upper and lower layers, clarified the structure and theoretical basis of the doublestaggered arranged porous nozzle, established the spray and combustion models to study the spray characteristics of the doublestaggered arranged porous nozzle and the influence of its structural parameters on combustion and emissions performance of the common rail diesel engine. The spray simulation shows that the doublestaggered arranged porous nozzle has a shorter injection distance and better spatial distribution of fuel properties compared with conventional nozzle. The influence of structural parameters of doublestaggered arranged porous nozzle on common rail diesel engine combustion and emission performance shows that the upper nozzle spray angle using a large one or under nozzle using a small diameter, can make the diesel combustion and emissions performance further improved.

Key words: common rail diesel, double-staggered arranged porous nozzle, spray characteristics, combustion and emission