Three-Dimensional Multiphysics Simulation of Gas-Assisted Electrochemical Jet Machining for Hole Inner Surfaces

Deep-small holes with microstructured inner surfaces have wide applications owing to their exceptional heat transfer performance. Nevertheless, machining the internal features in deep-small holes presents significant challenges. Recently, a gas-assisted electrochemical jet machining (EJM) method has been developed for microstructuring hole inner surfaces. However, owing to the complex physical interactions and the invisible in-hole processing environment, the experimentally driven process design remains difficult and time-consuming. In this study, a three-dimensional (3D) multiphysics model was established to numerically investigate the machining mechanism of this novel EJM process and facilitate simulation-based process design. Experiments were conducted in parallel for simulation validation. The interplay between the gas-electrolyte flow field, electric field, and material removal pattern during the machining of hole inner surfaces was analyzed, revealing distinct process characteristics compared to conventional planar surface machining. The influence of key process parameters, including the assistance gas velocity and machining gap, on the underlying physics and machining results was investigated. The results demonstrated the critical role of gas assistance in process control and established the applicability of this novel EJM method for holes of varying diameters. Complex features were successfully machined on hole inner surfaces using the developed gas-assisted EJM process with optimized parameters. A 3D multiphysics model is developed for simulating the gas-assisted EJM process of hole inner surfaces.In-depth insights are provided into the machining mechanism of this gas-assisted EJM process.Parametric effects are revealed, enabling simulation-based design of this gas-assisted EJM process.The assistance gas demonstrates anisotropic compression on the jet, thereby affecting the electric field distribution and material removal pattern.Suitable assistance gas control enables quasi-Gaussian material removal pattern similar to conventional EJM.