基于FLUENT的2D高频阀气穴现象研究

2D高频阀(简称数字阀)是利用阀芯旋转时阀芯台肩沟槽与阀套窗口组成的阀口周期性高频通断进行工作的.若阀口处存在气穴现象,将会产生噪声、振动,严重时会产生气蚀现象,破坏阀口处流体的连续性,甚至影响阀控缸的工作特性.利用CFD商用软件FLUENT对数字阀内部的流场进行数字计算,主要研究阀口的气穴现象.研究结果表明:数字阀阀口在即将关闭和关闭后一段时间内都会在阀口的低压侧产生气穴现象,即低压侧的阀套主窗口或阀芯沟槽内气穴现象都分成两个阶段,但气穴现象在其内部产生的速度、扩散的面积及持续的时间有所不同.这对优化数字阀的结构,降低数字阀的气穴、噪声,提高数字阀的流量具有参考价值.

Investigation of Cavitation Phenomena in the Valve Port of 2D High Frequency Valve Based on FLUENT

The function of 2D high frequency valve(abbr.digital valve) is achieved by periodical on-offs of the valve ports which is formed between the spool shoulders grooves and the sleeve windows,when the spool rotates in the sleeve.Noise and vibration will be induced if cavitation phenomena exist in the valve ports.Severely,the solid materials of valve ports will be subjected to cavitation erosion,and the fluid through the valve ports will be discontinued.As a result,the working characteristics of valve-controlled cylinder will be deteriorated.The commercial CFD(Computational Fluid Dynamics) software FLUENT6.3 was used to simulate the flow field inside the digital valve,and the changing rules of the cavitation were revealed.Simulation results show cavitation phenomena are occurred in the lower pressure side in the imminent closure and last a period of time after the closure of the valve ports.However,cavitation phenomena produced in the spool shoulders grooves is different from that in the sleeve windows,such as the speed of cavitation generated,diffusion area and the duration of cavitation.The results provide some useful reference for optimizing the valve structure and reducing cavitation phenomena.