【摘要】 控制阀是电控单体泵燃油系统中的关键部件,该阀通过快速打开导通高、低压油路,实现喷嘴处的断油控制,该过程是一个动态过程.通过理论分析得出,导致控制阀流场为非定常流动的原因是阀芯的快速运动和进/出口压力的瞬态变化使燃油产生加速度,该加速度使燃油惯性力增强.通过控制阀区域流场动态及稳态仿真计算对比了控制阀阀芯区域在稳态和动态条件下的流场特性,结果表明:随着开度的增加,动态时空化呈增强趋势,而稳态则呈减弱趋势;在整个打开过程中,动态与稳态下锥面进/出口燃油流速存在较大差异;小开度时稳态流通能力强于动态,大开度时则相反.更多还原

【Abstract】 Control valve is one critical component of electronic unit pump fuel system.Control valve controls the pressure build-up within the high-pressure fuel line through rapid opening,which is a dynamic process.On the basis of theoretical analysis,there are two key reasons for the unsteady flow within the control valve:one is the acceleration of fuel which is induced by the valve needle’s dynamic movement,and another is the acceleration of fuel flow due to the change of the inlet/outlet pressure,and this acceleration of fuel flow enhances the inertia force.Comparison of the flow field characteristics of the control valve are made under both steady and dynamic conditions by simulation.Results show that with the increase of valve opening,the cavitation becomes stronger under the unsteady condition but cavitation declines under the steady condition.There are significant differences between steady and unsteady conditions on the flow velocity during the whole opening process.In small valve needle opening,the flow capacity of steady condition is higher than that of unsteady condition;however,with the increase of valve opening,the flow capacity of unsteady become greater than that of steady flow.更多还原