Research on Multi-Physical Field Coupling Simulation of Local Electrochemical Machining

Casing is one of the most important components of an aircraft engine. However, due to its thin wall thickness and difficult-to-cut materials, it is difficult to process with a conventional mechanical method. Counter-rotating electrochemical machining (CRECM) is a special electrochemical machining method, which is very suitable for machining aircraft engine casing parts. However, for the convex structure with large surface height and a complex shape of the casing, is sometimes difficult for CRECM to obtain the desired design accuracy. Local electrochemical machining is proposed under this background, which is used for after-machining of the pre-shaped convex structure by CRECM. In order to predict the local electrochemical machining result accurately and improve the machining precision, this paper establishes a multi-physical field coupling simulation model of the local electrochemical machining considering the influence of gas-liquid two-phase flow and temperature field. The influence of a gas-liquid two-phase flow field and temperature field on the conductivity distribution were simulated and analyzed, the reason for simulation error with pure electric field and the influence of cathode end width L on machining accuracy was analyzed, and it was found that the gas-liquid two-phase flow field played a major role in the simulation results of local electrochemical machining. The experimental results show that there is a significant error between the pure electric field simulation results and the experimental results, and the multi-physical field coupling simulation results are basically consistent with the experimental results. The multi-physical field coupling simulation can predict the results of local electrochemical machining with high accuracy and has important significance for improving the precision of local electrochemical machining.

Automated summary

Casing is crucial in aircraft engine and traditional mechanical methods are not suitable for processing due to its thin wall thickness and difficult-to-cut materials. Counter-rotating electrochemical machining (CRECM) is used for machining aircraft engine casing parts, however, it is sometimes challenging to achieve the desired accuracy for complex convex structures. In this paper, a local electrochemical machining method is proposed for after-machining of pre-shaped convex structures by CRECM. A multi-physical field coupling simulation model considering the influence of gas-liquid two-phase flow and temperature field is established to accurately predict the local electrochemical machining result and improve machining precision. The experimental results show that the multi-physical field coupling simulation can predict the results of local electrochemical machining with high accuracy and has significant importance for improving the precision of this machining technique.