偏导射流阀前置级流场特征参数的仿真计算

根据偏导射流阀前置级的结构以及内部油液的流动特性，将前置级射流过程分为两个阶段。采用标准k-e模型对前置级流场进行了两相流二维数值计算，对两次射流过程中油液的流动形态以及流场压力和速度分布特点展开研究。分析得出，初次射流为自由紊动射流，二次射流为冲击射流，并发现在偏转板处于中位时两接收腔外侧圆弧拐角低压区处出现空化现象。偏导射流阀实际工作过程中偏转板会发生偏移，因此，建立了不同偏移量下的仿真模型，分析了不同偏移量下流场信息的变化规律，获得了前置级流场的压力云图以及对应的速度矢量图。利用仿真结果中两接收腔压力值和V形槽两侧壁静态压力数据，分别计算出了前置级流场的压力增益和液动力的大小。为偏导射流阀基础特性的深入分析奠定了基础，并对该类阀设计的改进和优化具有理论指导意义。

Simulation Calculation of Characteristic Parameters for Deflector Jet Valve's Flow Field

Based on structure of pre-stage in deflector jet servo valves and flow characteristics of internal fluid, the pre-stage jet process is divided into two stages. The standard k-e model is used to calculate the two-dimensional flow field of two-phase flow in the pre-stage flow field. The flow pattern of oil and characteristics of pressure and velocity distribution in the flow field are studied. The results show that the initial jet is a turbulent jet and the second jet is an impinging jet. It is found that cavitation occurs at low pressure zone of outer arc corner of two receiving chambers when the deflector is in the middle position. In the actual operation process of deflecting jet valve, the deflection plate will shift. Therefore, simulation models with different offsets are established, and the variation rules of flow field information under different offsets are analyzed. A pressure cloud map and a corresponding velocity vector map of pre-stage flow field are obtained. We calculate pressure gain and hydrodynamic force of pre-stage flow field by using the two receiving cavities pressure values and the static pressure data on both sides of V groove. The research lays a foundation for deep analysis of basic characteristics of deflector valve and has a theoretical guiding significance for improvement and optimization of the design of this type of valve.