液压圆柱滑阀K-K型节流槽流量面积参数模型

Flow Area Parameter Model of K-K Shape Notch of Hydraulic Cylinder Spool Valve

针对K-K型节流槽流量系数复杂时变及结构参数强耦合的特征,采用流量面积参数模型(FAPM),开展了液压圆柱滑阀K-K型节流槽阀口流量压降特性研究。首先,推导出K-K型节流槽阀口面积的数学模型,并将其等效为3个单阶K型节流槽阀口面积的组合形式;其次,基于计算流体动力学(CFD)和响应面模型(RSM),建立了极限饱和流量下K-K型节流槽的FAPM模型;最后,通过对FAPM模型的分析,得到组合型节流槽阀芯结构与流量压降的映射关系。研究结果表明:当入口体积流量大于7.31 L/min时,满足极限流量饱和条件,此时流量系数与入口体积流量无关;当入口体积流量分别为20、30、50 L/min时,FAPM模型预测的K-K型节流槽阀口压降与CFD仿真值的平均误差均控制在7%以内。该模型完成了对K-K型节流槽阀芯结构的近似表达,并可应用于其他类型的组合型节流槽。

Aiming at the complicated time-variant flow coefficients and strong coupling notch structure parameters of K-K shape notches,the research of K-K shape notch flow pressure drop characteristics of the hydraulic cylinder spool valve is carried out using the flow area parameter model(FAPM).First,the mathematical model of K-K shape notch’s flow area is derived,which is equivalent to the combination of three single-stage notches.Then,based on computational fluid dynamics(CFD)and response surface model(RSM),the FAPM model of the K-K shape notch under limit saturation flow is established.Finally,the mapping relationship between the combined notch spool structure and flow-pressure drop is obtained on the basis of the FAPM model.The results show that the limit saturation flow requirement is met when the inlet volume flow is 7.31 L/min,and the flow coefficient is independent of inlet volume flow at this moment.When the inlet volume flow is 20,30 and 50 L/min,the average deviations of the K-K shape notch valve port pressure drop between the value predicted by the FAPM model and the CFD simulation value are all below 7%.The proposed model effectively realizes the approximate expression of K-K shape notch structure and can be applied to other types of notches.