二维阀先导级污染颗粒分布的数值模拟

Numerical Simulation of Pollution Particle Distribution in 2D Pilot Stage of Valve

二维阀将先导级和功率级集成在一个阀芯上,易于实现阀的快速工作和高频响应,具有体积小、性能稳定、功重比大等优点。通过数值计算,分析不同参数条件下固体颗粒在二维阀内的分布特点和规律,揭示二维阀对油液污染的敏感程度。结果发现:阀芯转动形成的节流口,其上下游压差与射流形成的旋涡离心力的共同作用,使得固体颗粒物极易进入阀套斜槽区形成聚集现象;固体颗粒在旋涡中心区域分布较少,在旋涡边缘区域,特别是阀套斜槽外侧浓度较高。节流口开度、固相密度、颗粒粒径的不同,均对固体颗粒的分布产生影响,总体来看,旋涡态流束对其分布影响最大,即斜槽周边浓度大、中间区域浓度低,二维阀对油液污染较为不敏感。阀芯正、反转对阀套斜槽区内固相颗粒的体积分数分布影响不大。

The 2D valve integrates the pilot stage and the power stage into one spool,which is easy to realize the fast operation and high frequency response of the valve.It has the advantages of small size,stable performance and large power to weight ratio.Through numerical calculation,the distribution characteristics and rules of solid particles in 2D valve under different parameters were analyzed,and the sensitivity of 2D valve to oil pollution was revealed.The results show that the combined action of the pressure difference between upstream and downstream of the orifice formed by the spool rotation and the vortex centrifugal force formed by the jet makes the solid particles easily enter the chute area of the valve sleeve and accumulate.The solid particles are less distributed in the vortex center,and more concentrated in the vortex edge,especially outside the valve sleeve chute.The difference of orifice opening,solid phase density and particle size all affect the distribution of solid particles.In general,the vortex flow beam has the greatest influence on its distribution,that is,the concentration around the chute is large,and the concentration in the middle area is low.The 2D valve is not sensitive to oil pollution.The positive and reverse spool has little effect on the volume fraction distribution of solid particles in the chute of valve sleeve.