射流管式伺服阀冲蚀磨损特性

Erosion wear characteristic of jet pipe servo valve

射流管式伺服阀是一种典型的两级流量控制电液伺服阀,其喷嘴至接收器部位的流场最复杂,会因液压介质的污染而产生冲蚀磨损。以射流管式伺服阀为研究对象,将计算流体力学(CFD)理论与冲蚀磨损理论相结合,应用雷诺平均Navier-Stokes方程、标准k-ε两方程模型(液相)、离散相模型(DPM)(固相)和塑性材料冲蚀磨损模型,通过流体动力学软件FLUENT建立射流管式伺服阀喷嘴至接收器部位的可视化仿真模型,并进行了冲蚀磨损率的数值模拟和理论寿命的计算。研究结果表明:液压介质中的固体颗粒对射流管式伺服阀的冲蚀磨损主要集中于左右接收孔所夹中间内壁区域,磨损率最大值随喷嘴偏移量的增加而减小且此趋势左右对称。研究方法和结果对于射流管式伺服阀故障的定性分析、预测和理论寿命的定量计算具有重要参考价值。

The jet pipe servo valve is a kind of typical two-stage flow control electro-hydraulic servo valve; the flow field of the nozzle to the receiver parts is the most complex part, which can produce erosion wear because of the pollution of hydrau- lic medium. Taking the jet pipe servo valve as the research object, combining the theory of computational fluid dynamics （CFD） with the erosion wear theory, applying Reynolds averaged Navier-Stokes equations, the standard k-ε two-equation model （liquid phase）, discrete phase model （DPM）（solid phase） and the erosion wear model of plastic material, through the fluid dynamics software FLUENT, we establish a visual simulation model of the nozzle to the receiver parts of the jet pipe servo valve, conducte the erosion wear rate of the numerical simulation and calculate the theoretical life in this paper. The research results demonstrate that the erosion wear of the solid particle in the hydraulic medium to the jet pipe servo valve is mainly focused on the middle inwall area between the left and right receiving holes, the maximum wear rate decreases with the increase of the offset of the nozzle and the trend of left and right sides is symmetrical. The methods and results have pro- vided an important reference for failure＇s qualitative analysis and forecast and theoretical life＇s quantitative calculation of the jet pipe servo valve.