基于CFD的压电驱动精密流量阀流场仿真分析

发布时间：2018-06-29 04:59

本文选题：压电陶瓷 + 流场仿真分析　；参考：《南昌大学》2016年硕士论文

【摘要】：随着社会的发展,在航空航天、生物工程、医疗器械等领域,对其控制系统也提出了体积更小、重量更轻、降低能耗、提高性能的要求,因此对超高压、微流量精密控制系统的研究尤为重要。但在传统的流量控制阀研究领域,原有的阀芯驱动器很难满足需要。从而加快了对新的微流体驱动控制系统的研究并已有所成效。在智能材料领域,压电陶瓷由于具有位移控制精度高、力输出明显、响应快、功耗小和便于数字化等优点被广泛应用于阀芯的驱动。本文以压电陶瓷作为驱动元件,利用压电陶瓷的逆压电效应产生的微位移来驱动阀芯运动,从而实现对流量阀的精密控制来进行研究。随着三维建模软件的成熟和计算机技术的应用的迅速发展,利用数值计算方法来研究阀内部流体的流场分布已经能够取得很好的效果。本文利用三维建模软件建立阀的整体结构和阀内流体模型,运用前处理软件对流体模型进行网格划分,选用CFD软件对阀的内部流场进行了仿真分析。首先,通过对不同阀芯半锥角和不同阀芯直径的流体模型进行流场仿真,得到了不同条件下的流场参数和流场分布规律,比较分析流体纵面的流场压力云图、速度矢量图、湍动能云图、迹线流量图的变化情况,确定了阀芯的半锥角和直径的数值。然后,根据阀内部流体的流场仿真结果,对阀的结构进行改进,分析比较改进前后的流场参数和流场分布状况,有效的改善了流场的分布状态和部分参数,提高了阀的使用寿命。最后,对相同阀芯开口度不同进出口压差时的流场进行分析比较,得到了进出口压差对阀内流场参数和分布的影响规律,为压电驱动精密流量阀的结构设计改进和合理选择边界条件提供了理论依据和参考。
[Abstract]:With the development of society, in the fields of aerospace, bioengineering, medical device and so on, the control system is required to be smaller in volume, lighter in weight, lower in energy consumption and better in performance. The research of micro-flow precision control system is particularly important. But in the traditional flow control valve research field, the original valve core driver is difficult to meet the needs. Thus, the research on the new micro-fluid drive control system has been accelerated and some results have been achieved. In the field of intelligent materials, piezoelectric ceramics have been widely used in the drive of valve core because of its high displacement control accuracy, obvious force output, fast response, low power consumption and easy digitization. In this paper, piezoelectric ceramic is used as the driving element, and the micro-displacement caused by the inverse piezoelectric effect of the piezoelectric ceramic is used to drive the movement of the valve core, thus the precise control of the flow valve is studied. With the maturity of 3D modeling software and the rapid development of computer technology, the numerical calculation method has been used to study the flow field distribution in the valve. In this paper, the whole structure of the valve and the fluid model in the valve are established by using three-dimensional modeling software, and the fluid model is meshed by pre-processing software, and the internal flow field of the valve is simulated and analyzed by using CFD software. First of all, through the flow field simulation of the fluid models with different core semi-cone angles and different spool diameters, the flow field parameters and flow field distribution laws under different conditions are obtained, and the flow field pressure cloud diagram and velocity vector diagram of the longitudinal plane of the fluid are compared and analyzed. The change of turbulent kinetic energy cloud diagram and trace flow chart is used to determine the half cone angle and diameter of the valve core. Then, according to the simulation results of the flow field inside the valve, the structure of the valve is improved, the flow field parameters and the flow field distribution are analyzed and compared before and after the improvement, and the distribution state and some parameters of the flow field are effectively improved. The service life of the valve is increased. Finally, the influence of inlet and outlet pressure difference on the flow field parameters and distribution is obtained by analyzing and comparing the flow field of the same valve core opening degree and different inlet and outlet pressure difference. The theoretical basis and reference are provided for the structure design improvement and reasonable selection of boundary conditions of piezoelectric actuated precision flow valve.
【学位授予单位】：南昌大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TH134

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