基于Realizable k-ε模型的叶盘通道电解加工多场耦合分析

Multi-physical field analysis of tunnel ECM employed Realizable k-εmodel

叶盘通道电解加工(ECM)是决定整体叶盘电解加工成形精度的关键工序,其加工间隙不规则、建模困难。基于Realizablek-ε模型建立叶盘通道电解加工的气液两相流模型,根据参数传递关系建立多物理场耦合模型,分析加工间隙内电解液温度、氢气体积分数、电导率等重要参数的分布规律。仿真结果显示电解液在侧面间隙出现涡流现象,使该区域氢气堆积、温度上升,影响工件的成形表面质量,并导致该处的材料蚀除量减小,该结果在试验中得到证实。试验与仿真得出的工件轮廓形状变化趋势一致,试验与仿真获得的端面平衡间隙尺寸分别为0.26、0.33mm,仿真的相对误差(27%)明显小于经典公式的相对误差(73%)。因此,模型可较为准确地模拟叶盘通道电解加工成形过程,反映各参数对工件成形的影响过程。

Tunnel ECM is a key process that affects the machining accuracy of blisk ECM of which the forming model is difficult to establish.In this paper,a two-phase flow model based on Realizable k-εmodel is established,and a multi-physical field coupling model is built based on the parameter relationship of tunnel ECM.The parameter distribution of temperature,hydrogen volume fraction and electrolyte conductivity in the process and their influence on the surface quality were analyzed by simulation,which shows the vortex region in the side gap increases hydrogen volume and electrolyte temperature.This phenomenon affects the surface quality,decreases the material removal rate,and is verified by the experiments.The balance gaps obtained by simulation and experiment are 0.33 mm and 0.26 mm.Thus the relative error of simulation(27%)is much lower than that of theoretical calculation(73%).Therefore,the model is consistent with the forming process and reflects the influence of machining parameters on the workpiece forming of blisk tunnel ECM.