高压共轨喷油器内非稳态流动数值模拟

针对高压共轨喷油器内部非稳态流动现象，建立起瞬态流动的物理-数学模型，采用模块化分析方法进行了瞬态数值模拟．通过与试验结果的比较，验证了数值计算模型的准确性．在此基础上通过变参数数值模拟，分析了电磁阀通电时间、共轨压力、控制室进出口节流孔孔径及针阀弹簧预紧力对喷油过程的影响．结果表明：高压共轨喷油器不同结构参数对其动态特性、喷油率及循环喷油量等性能指标有很大的影响．其中，控制室进出口节流孔孔径的合理匹配和组合对获得良好的喷油特性尤为关键；燃油喷射系统要实现预喷，电磁铁的响应速度必须非常快．

Numerical simulation of transient flow in high pressure common rail injector

The mathematic model of the transient flow was set up to study the unsteady flow phenomena in the high-pressure common-rail injector.The numerical simulation was realized by applying the calculation analysis technique of block.The numerical simulation was validated by comparison with experimental results.Based upon the model,the numerical simulation was applied.The results show that the different structural parameters of the high-pressure common-rail injector have strong effects on the dynamic characteristic,injection rate and cycle fuel injection quantity.Among them,the inlet and outlet throttle hole diameters of the control volume are the key for the better injection performance.In this injection system,the electromagnet response speed has to be very fast in order to realize the pre-injection.