数控电解加工整体叶轮阴极三维流场数值模拟

Numerical Simulation of Three-dimensional Flow Field of Cathode of NC-Electrochemical Machining in Machining Integral Impeller

针对数控展成电解加工整体叶轮通道阴极流场设计,建立阴极内流体流动的三维物理模型,同时由电解加工过程中电解液运动为湍流状态,应用三维湍流Navier-Stokes、标准k-ε两方程湍流模型对稳定加工状态时加工间隙中电解液的流场进行了三维数值模拟研究。研究结果揭示了在电解加工稳定状态下不同加工间隙、不同加工区域时在加工表面上的速度矢量及压力等值分布情况,据此对阴极流场提出相应改善方案,并与试验结果进行比较,其数值模拟结果与试验结果基本一致,表明采用计算流体动力学方法对电解加工中阴极流场的设计进行理论指导是可行的。

In order to design the flow field of cathode for machining integral impeller in the NC--electrochemical machining （NC--ECM）, a three--dimensional physical model of the flow passage was constructed according to the fluid flow＇s movement characteristics, then three--dimensional flow field was simulated by the usage of the Reynolds time--averaged Navier--Stokes equations and the standard k-ε turbulence numerical model when the turbulence state in electrochemical machining had ,been determined. Pressure contours and velocity vectors on machined surface were showed when steady state was obtained in electrochemical machining. Improvement method was given according to numerical simulation results. Comparing the simulation results with the experimental ones, it is indicated that guiding the design of the cathode by computational fluid dynamics （CFD） simulation is accurate and practicable.