• CN:11-2187/TH
  • ISSN:0577-6686

›› 2013, Vol. 49 ›› Issue (2): 165-173.

• 论文 • 上一篇    下一篇

新型高压电-气伺服阀阀口气体射流数值研究

杨钢;高隆隆;李宝仁   

  1. 华中科技大学FESTO气动技术中心
  • 发布日期:2013-01-20

Numerical Simulation of Spool Orifice Gas Jet for Novel High Pressure Electro-pneumatic Servo Valve

YANG Gang;GAO Longlong;LI Baoren   

  1. FESTO Pneumatic Technology Centre, Huazhong University of Science & Technology
  • Published:2013-01-20

摘要: 提出一种新型音圈马达直接驱动滑阀式单级高压电-气伺服阀,针对其工作特点及阀芯受力情况,研究高压气体流经伺服阀阀口时气体射流角。在高压电-气伺服阀中阀口上下游压力比达到临界状态时,高压气体流经较小阀口时流速可达到声速,此时高压、高速气流产生的稳态气动力不容忽视,成为影响音圈马达直接驱动滑阀式单级高压电-气伺服阀控制精度及响应特性的重要干扰力。基于气体射流理论采用计算流体动力学方法对高压电-气伺服阀内部流场进行数值模拟,分析不同阀口开度对应的射流角大小,得出高压电-气伺服阀在不同阀口开度时射流角有较大差异,小阀口开度时射流角大于69°,当阀口开度达到设计最大开度时射流角接近69°,但伺服阀在精密控制系统中主要工作在零位附近,此时阀口开度较小,因此不同开度对应稳态气动力均采用射流角为69°的经典理论计算会产生较大误差。关于阀口射流角的数值研究可为高压气动伺服阀的研制及高压气动技术的发展提供一定的理论基础。

关键词: 高压电-气伺服阀, 矩形阀口, 气体附壁射流, 射流角, 数值模拟

Abstract: A novel voice coil motor direct-drive single stage high-pressure pneumatic servo valve is designed. And then the gas flow jet angle is investigated with numerical simulation, while the high-pressure gas flows through the valve orifice for the servo valve. At present, many studies about flow force are concentrated mainly on hydraulic valves, not on pneumatic valves. It is the reason that the gas flow force acting on the spool of low-pressure pneumatic valve is less, owing to small viscosity and density of low-pressure gas; besides the research on high-pressure pneumatic servo valve is seldom-reported so far. However, the velocity of gas flow is up to sonic when high-pressure gas flows through the micro servo valve orifice. And therefore, the steady gas flow force, generated by high pressure and high speed gas flow, cannot be neglected and is an important disturbance for the voice coil motor direct-drive high-pressure pneumatic servo valve. The jet angle for spool valve is usually considered as 69° to calculate the steady flow force, whose prerequisite is two-dimensional, irrational, inviscid and incompressible flow. In this paper, the high pressure gas flows through the servo valve is 3D compressible flow. Consequently, the numerical simulation with computational fluid dynamics(CFD) is adopted to analyze the internal flow filed and jet angles for the servo valve orifice with different valve openings. The simulation results are compared with classical theoretical formula, the results demonstrate that the gas jet angle for the servo valve is more than 69° and different with various spool openings.

Key words: High-pressure electro-pneumatic servo valve, Jet angle, Numerical simulation, Rectangle spool valve orifice, Wall-attached gas jet

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