【摘要】 高速开关阀内部存在相对复杂的流动状态,在阀芯高速启闭过程中产生低压区和油液回流,引起气穴和旋涡等现象,影响板阀内部流场稳定性以及高速开关阀的流量特性。针对高速开关阀流量小和内流场不稳定的问题,设计了一种新型的阀芯结构,建立了不同开口的二孔和三孔板绕轴的流场模型,并选择ANSYS Workbench软件对模型进行了网格化处理。基于FLUENT仿真软件,选择标准k-ε湍流模型进行数值模拟研究,得到了在相同压力和不同开口度下的压力分布和速度分布。得到了优化模型的结构和参数。对不同压力下的流场进行了稳定性分析,三孔阀芯的流场变化与二孔阀芯相似,但不会形成低压区,三孔阀芯在2 MPa及以下均能稳定工作。改善了阀芯高速开闭过程中低压区和油液回流现象,提高了高速开关阀的流场稳定性和流量。最后对比了本文设计的板式高速开关阀和现有液压阀产品的流量特性。结果表明,本文设计的三孔板式高速开关阀在200Hz和较大开口度下能够保持内流场稳定,并且实现了流量的提升。更多还原

【Abstract】 There is a relatively complex flow state inside the high speed on-off valve, which often produces low pressure area and oil reflux in the high-speed opening and closing process of the spool, causing cavitation and vortex and other phenomena. These phenomena will affect the stability of the internal flow field of the plate valve and the flow characteristics of the high speed on-off valve. Aiming at the problems of small flow rate and instability of internal flow field, a new spool structure was designed. The flow field models of two-hole and three-hole plate spools with different openings were established, and software ANSYS Workbench was chosen to mesh the model. The standard k-ε turbulence model was selected for numerical simulation using FLUENT software. The pressure distribution and velocity distribution under the same pressure and different opening degree were obtained. The structure and parameters of the optimization model were also obtained. The stability analysis of flow field under different pressure was carried out. The results demonstrate that the three-hole spool has a similar flow field change with the two-hole spool, but it does not create a low pressure zone, and the three-hole spool can work stably at 2 MPa or less. This method improves the appearance of low pressure area and oil backflow in the process of high speed opening and closing of spool. The stability of flow field and the flow rate of high speed switch valve are improved. Finally, the products designed in this paper are compared with existing hydraulic valve products. The results show that the three-hole plate type high speed on-off valve designed in this paper maintains the stability of the internal flow field under the condition of 200 Hz and large opening degree, and realizes the increase of flow rate.更多还原