Study On The Characteristics Of Flow State In Micro-scale Channel

Electrochemical Finishing is a technology take use of electrochemical processes in the oxidation reduction reaction to dissolve or increase metal materials. The processing effect is not only affected by the power supply system, the liquid supply mode and other factors, but also the distribution of the electric field and electric field in the gap and the discharge status of various electrolytic products. Because of the small size of the gap between the anode and the cathode and workpiece surface roughness element of will of small scale electrolyte flow generated relatively large impact, thus changing the anodic dissolution conditions, the bad flow condition can lead to partial passivation of the workpiece or even short circuit. So it is important to study the flow characteristics of the electrolyte to get stable and uniform flow state and improve the machining quality of the parts.In this paper, the important effect of electrolyte flow on the surface quality is introduced. The basic theory and the coupling relationship between the electric field and the flow field are discussed. Two kinds of roughness elements with different morphologies were simulated by Ansys software, and the flow of the small clearance flow field was simulated. The distribution of pressure and the velocity vector of the flow field in the machining area were obtained. On the other hand, the electrolyte flow field more clearly on anode roughness element dissolution mechanism, on the basis of finite element method using Comsol multiphysics software flow field between the electrodes geometry model is established and discussed under different machining time electrolyte in electrolyte concentration and the electric flow density changes. Has been fluid shear rate, viscosity unit wall lift, turbulence dissipation rate and potential distribution map, calculate the different time anode profile curve, due to workpiece surface morphology changes of inter electrode current field effect. In the experiment, the Charge Coupled Device(CCD) camera was used to capture the image of the particle in the fluid, and the multiple exposure images of the tracer particles were photographed and recorded, and the results were further confirmed by simulation. The influence of the shape of the anode profile on the stability of the flow field is analyzed.The results showed that different morphologies of roughness elements on the flow field of disturbance effect is different, processing at the beginning of the rough element bottom formed more easily secondary vortex flow, forming the electrolyte accumulation; and post processing the height of the roughness element decreased make the liquid turbulence is more uniform, the flow resistance decreases gradually,the retention domain disappears, along with the extension of processing time,electrolyte concentration gradually decreased and dissipated. In addition, it is found that the anodic dissolution rate will be affected by the roughness element size and spacing. To provide a reference for the research of how to eliminate the stagnant regions and concentration polarization, improve the stability of electric field and flow field.