基于CFD和FEM的超磁致伸缩驱动水压伺服阀性能研究

发布时间：2018-02-14 18:38

本文关键词： 超磁致伸缩水压传动伺服阀 CFD 有限元法　出处：《北京工业大学》2011年硕士论文　论文类型：学位论文

【摘要】：超磁致伸缩材料(GMM)是一种具有应变大、响应速度快、能量传输密度高、输出力大等优异性能的新型功能材料。基于超磁致伸缩驱动器(GMA),提出了一种新型的双相对置超磁致伸缩自传感驱动水压伺服控制阀,并以此为研究对象,采用了计算流体力学(CFD)、有限元法(FEM)以及自动控制系统MATLAB动态仿真等方法,对所设计的双相对置超磁致伸缩自传感驱动水压伺服阀进行了系统、深入的分析和研究。基于流体力学中管道流动和各种典型节流口流动理论,对超磁致伸缩水压伺服阀的液压桥路进行了理论分析,建立了液压桥路简化模型和阀芯两端压差与挡板位移之间的关系式,验证了后续仿真分析结果的正确性。利用CFD稳态流技术研究了挡板和喷嘴前端面的压力分布,以及阀芯两端压差随着挡板位置的变化情况。利用CFD动网格技术建立了滑阀启闭过程的动态计算模型,节流口的大小变化通过FLUENT软件中的UDF函数来定义,研究了开口量逐步减小过程中流场的分布情况。对两种不同结构型式的滑阀进行了CFD动网格分析,结果表明带有环形槽的滑阀产生了较小的稳态液动力。利用CFD稳态流技术计算得到滑阀阀芯的径向不平衡力。结果表明,径向不平衡力远远小于静压支撑力,阀芯可很好的悬浮于阀套内。利用ABAQUS软件的ABAQUS/Standard模块对喷嘴头和喷嘴块的过盈配合进行了仿真分析,比较了不同温度下接触力的变化情况。仿真表明,由于温度的升高和材料的线膨胀效应,接触应力会发生变化,但是总体来说接触应力变化不大,喷嘴头和喷嘴块能保持很好的接触。对水压伺服阀的反馈杆-滑阀组件的稳定状态进行了力学分析,提出了伺服阀稳态分析的有限元计算模型。计算得到了不同反馈杆配置下水压伺服阀滑阀的位移输出,可用于指导设计出合适粗细的反馈杆。提出了双相对置超磁致伸缩驱动器的等效动力学模型,并由此得到了磁致伸缩水压伺服阀的物理传递模型。利用自动控制系统MATLAB动态仿真方法对该伺服阀的物理模型进行了仿真。结果表明,该阀的响应时间为0.016s,幅频宽为60Hz,相频宽为50Hz,能够满足快速响应的要求。
[Abstract]:Giant Magnetostrictive material (GMMM) is a kind of material with large strain, high response speed and high energy transfer density. Based on giant magnetostrictive actuator (GMA), a new type of double relative giant magnetostrictive self-sensing drive hydraulic servo control valve is proposed. By using the methods of computational fluid dynamics (CFD), finite element method (FEM) and dynamic simulation of automatic control system (MATLAB), the design of double relative giant magnetostrictive self-sensing driven hydraulic servo valve is systematically analyzed and studied. Based on the theory of pipe flow and various typical throttle flow in hydrodynamics, the hydraulic bridge of giant magnetostrictive hydraulic servo valve is analyzed theoretically. The simplified model of hydraulic bridge and the relationship between the pressure difference between the two ends of the valve core and the displacement of the baffle are established to verify the correctness of the subsequent simulation results. The pressure distribution of the baffle and the front end of the nozzle is studied by using the CFD steady flow technique. And the pressure difference between the two ends of the valve core with the change of baffle position. The dynamic calculation model of sliding valve opening and closing process is established by using CFD dynamic grid technology. The change of throttle port is defined by UDF function in FLUENT software. The distribution of the flow field in the process of gradual decrease of the opening is studied. The CFD dynamic grid analysis of two kinds of sliding valves with different structures is carried out. The results show that the sliding valve with annular grooves produces small steady fluid power. The radial unbalance force of the valve core is calculated by using CFD steady state flow technique. The results show that the radial unbalance force is much smaller than the static pressure supporting force. The valve core is well suspended in the valve sleeve. The interference fit between nozzle head and nozzle block is simulated and analyzed by using ABAQUS/Standard module of ABAQUS software, and the change of contact force at different temperature is compared. The simulation results show that due to the increase of temperature and the linear expansion effect of material, The contact stress will change, but the contact stress will not change, and the nozzle head and nozzle block can keep in good contact. In this paper, the stable state of feedback rod and slide valve assembly of hydraulic servo valve is analyzed, and the finite element calculation model of steady state analysis of servo valve is put forward. The displacement output of slide valve of hydraulic servo valve with different feedback rod configuration is calculated. Can be used to guide the design of the appropriate thickness of the feedback rod. An equivalent dynamic model of double relative giant magnetostrictive actuator is presented. The physical transfer model of the magnetostrictive hydraulic servo valve is obtained. The physical model of the servo valve is simulated by using the automatic control system MATLAB dynamic simulation method. The response time of the valve is 0.016 s, the amplitude width is 60 Hz, and the phase width is 50 Hz, which can meet the requirement of rapid response.
【学位授予单位】：北京工业大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：TH137.52

【引证文献】