水压柱塞副的微流场特性研究

Research on the Micro-flowfield Characteristics of Water Hydraulic Piston Pairs

对于水压柱塞副间隙流场,水的流动惯性可能改变流场的局部甚至全局流态。综合考虑表面粗糙度和惯性力等因素,通过CFD仿真计算研究了包括水在内的几种不同黏度流体在柱塞副间隙流场中的压力和流量特性,并进行了试验对比验证。结果表明应用经典润滑理论得到的计算结果与实际情况有较大误差,设计计算时需要考虑惯性力和表面粗糙度的影响以及正确的流态,这是因为水的低黏度导致惯性力的效应增强,使得流态对表面粗糙度更敏感;表面粗糙度影响微流场的流态,最终影响摩擦副的压差流量特性。

For the clearance flowfield of water hydraulic piston friction pairs, the flow inertia of water possibly change the local even whole flow state. Considering comprehensively the surface roughness and inertia force, the pressure and flow- rate characteristics in the piston clearance flowfield for several fluids including water were researched by CFD simulation, and the comparison experiment was performed. The results indicate that the calculating results using the classical lubrica- tion theory have much error in comparison with the actual situation so that the effect of the inertia force and the surface roughness and the right flow state must be considered for the more accurate design results. The low viscosity of water makes the effect of inertia force much intensive so that the flow state is more sensitive to the surface roughness. Surface roughness the flow state of micro-flowfield and ultimately affects the pressure difference and flowrate characteristics.