Uniformity enhancement of flow field through optimizing nozzle structure for jet electrochemical machining

To improve the processing quality during the Jet electrochemical machining (JECM) process, a single-orifice nozzle and dual-orifice nozzles with different inclination angles were designed, where the fluid dynamic behavior was numerically simulated. Then, through the L₄₉ (7⁴) orthogonal design and error analysis, the influence of nozzle dimension on the flow field characteristics was analyzed. Finally, the nozzle with optimal structure and dimension was obtained and validated by experiment. Results show that the dual-orifice nozzles had better flow field uniformity than the single-orifice nozzle. In the dual-orifice nozzle, the increase of the inlet inclination angle can improve the flow field uniformity. The influence of the nozzle dimension parameters on the flow field uniformity is prioritized as follows: the outlet slit width > upper chamber diameter > the height of the inflow chamber > the height of the transition chamber. After optimization, the optimal dimension parameters were obtained under the upper chamber diameter of 16 mm, the jet outlet slit width of 0.4 mm, the height of the inflow chamber of 7 mm, and the height of the transition chamber of 23 mm. The flow velocity dispersions under the pressures of 0.3, 0.4, and 0.5 MPa can be reduced by 25.41 %, 25.17 %, and 28.16 %. The findings can help understand the flow behavior and guide the structure optimization for improving JECM quality.