喷油器结构对喷雾特性影响计算分析

Simulation Analysis on Spray Characteristics Effected by Injector Structure

将喷油嘴内部空穴流动和喷雾计算耦合在一起,首先利用一维液力计算结果为边界进行了喷油嘴内部流动计算,然后将喷油嘴内部流动计算结果作为边界条件进行喷雾模拟,包括计算所得到喷孔出口处的速度、空穴、湍流动能等,通过此方法研究了喷油器结构参数,如控制腔进油孔、出油孔和控制腔容积、针阀弹簧预紧力、控制活塞直径对喷雾特性的影响规律,结果表明:控制腔进油孔、出油孔和控制活塞直径对喷雾特性影响较大。

The coupling calculation of the cavitation flow and spray in the diesel nozzle is carried out in this paper.The nozzle cavitation flow simulations are made with the multiphase flow model based on results of simulation for the dynamic analysis of hydro-mechanical systems,and the flow field values at nozzle outlet will be used as the inlet boundary conditions of the multiphase spray model.Local values at nozzle outlet have subsequently to be extracted,involved the velocity,the turbulent kinetic energy,cavitations,etc.Based on this means,Spray characteristics with various injector geometry,such as the diameters of the inlet throttle and the outlet throttle,amount of the control volume and preload force of needle's spring,the diameter of control piston are studied in this paper.The results indicate that the diameters of the inlet throttle and the outlet throttle in the control volume,the diameter of control piston have great influence on spray characteristics.