关键词: 机械制造工艺与设备, 电解加工, 螺旋孔, 气液两相流, 流动特性

Abstract:

For the difficult prediction and control of the forming size during electrochemical machining (ECM), the three-dimensional simulation and verification experiments of the gas-liquid two-phase turbulent flow in the inter-electrode gap are performed by using Fluent software with mixture model, extended SIMPLEC algorithm and standard k -着turbulence model. A spiral deep small hole is used as the processing subject in ECM for simulation and experiment. The flow characteristic in the inter- electrode gap is revealed. The results show that the velocity of the mixture in the inter-electrode gap has an important effect on the discharge of the dissolution products. Flow speed decreases and the machining stability becomes worse with the increase in hole depth. The gas volume fraction increases and the electrical conductivity decreases along the direction of the electrolyte flow, resulting in the non-uniform of the machining size of the workpiece. Furthermore, a back pressure on the outlet could reduce the non- uniform. The shape of cathode influences the flow-field characteristics. The ‘dead zone爷, short circuit and spark could be avoided by properly designing the cathode shape.

Key words: machinofature technique and equipment, electrochemical machining, spiral hole, gas-liquid two-phase flow, flow characteristics