涡轮叶片气膜冷却孔电解加工气液两相流场特性分析

以高温镍基合金Inconel718为基材进行气膜冷却孔电解加工基础试验,在电解加工过程中,阴极反应界面析出氢气,导致电解液的电导率不再是一个常数,从而影响冷却孔的加工成型精度。结合前期基础试验,建立冷却孔电解加工流道二维模型,基于COMSOL Multiphysics软件对冷却孔端面间隙内气液两相流场进行仿真,研究加工电压、电解液入口压力及管电极进给速度对氢气析出量的影响,并定性地分析电解加工过程中气泡率与电导率之间的关系。由仿真结果可知:氢气的体积分数随加工电压和电极进给速度的增大而增大,随电解液入口压力的增大而减小,且氢气体积分数越大,电解液的电导率越小。

Analysis of Gas liquid Two phase Flow Field in ECM of Turbine Blade Film Cooling Holes

Film cooling holes are obtained by electrochemical machining using Inconel718 nickel based super alloy which is commonly used for turbine blade of aero engine.In the process of ECM, hydrogen is precipitated in the cathode reaction interface, which leads to the conductivity of the electrolyte no longer a constant. The influence of processing voltage, electrolyte inlet pressure and electrode feed rate on gas liquid two phase flow were studied based on COMSOL Multiphysics software and the relationship between hydrogen gas volume and electrical conductivity was analyzed qualitatively. The results show that the volume fraction of hydrogen increases with the processing voltage and the electrode feed rate, and decreases with the increase of the inlet pressure, and the greater the volume fraction of hydrogen, the smaller the conductivity of the electrolyte is.