电解加工异形型腔整体构件动态成形规律及流场变化特性研究

Integral component is the core component of advanced aerospace equipment to achieve structure innovation across and technological leap. Aiming at the problem of large processing difficulty and low forming precision in the manufacturing process of irregular cavity of integral component, the project carry out the research on the dynamic forming law and flow field characteristics for the irregular cavity of integral component in electrochemical machining, then a new “one-way inlet” controllable symmetric flow field of electrolyte was proposed, the favorable velocity field and pressure field were obtained and the stability and machining precision were improved by actively controlling the electrolyte flow patterns and flow field parameters. The three-phase flow model of gas, liquid, solid in the machining gap was established to analyze the change characteristics of electrolyte flow field in the forming process, and the mechanism of electrolysis products removal and transportation process was studied to realize the prediction of dynamic irregular cavity forming process. On the basis, the forming law model in the multi field interaction such as electric field, flow field and electrochemical field was established, the electric field and flow field distribution in the gap was also optimized, and the three dimensional irregular cavity electrochemical machining theory of forming law was constructed so as to lays the technical foundation for high efficiency, stability, precision manufacturing of integral component. This research project is very important for promoting the extensive application of electrochemical machining technology in aviation and aerospace manufacturing field.

整体构件是先进航空航天装备中实现结构创新与技术跨越的核心部件。本项目针对异形型腔整体构件的制造中存在的加工难度大、成形精度不高等问题，开展电解加工异形型腔整体构件动态成形规律与流场变化特性研究，提出一种新的“单向进液”可控对称式电解液流场，通过主动控制电解液流动方式及流场参数，形成有利的速度场和压力场，提高电解加工的稳定性及加工精度。通过建立加工间隙内气、液、固三相流模型，分析电解液流场在异形型腔成形过程中的变化特性及其对电解产物去除和运输过程的作用机理，实现对异形型腔动态成形过程的预测。在此基础上，建立间隙内电场、流场、电化学场等多场交互作用下的成形规律模型，优化间隙内的电场、流场分布，构建三维异形型腔电解加工成形规律的理论，从而为实现整体构件的高效、稳定、精密制造奠定技术基础。本项目研究对于促进电解加工技术在航空航天制造领域的广泛应用具有重要意义。

整体构件是高性能航空发动机实现结构创新和技术跨越的核心部件之一，由于结构复杂，材料难切削，加工精度要求高，其整体制造已成为了世界性的难题。项目组以整体叶盘这一典型的的异形型腔整体构件为研究对象，提出了主动控制“单向进液”电解加工模式，对异形型腔成形机理和电解液流场动态变化特性进行了深入分析，开展了以下研究工作：（1）搭建了可实现复合进给运动的电解加工实验平台，确定了合理机床总体布局和结构形式，研制了具有高精度的直线进给机构和回转运动机构，并对机床关键部件进行了结构拓扑优化设计和优化灵敏度分析，达到了机床精度指标要求。（2）基于PMAC硬件结构和LabVIEW 软件平台，构建了多轴联动伺服控制系统，实现了对刀控制、伺服进给、轨迹控制、过程监控等功能的高度集成，并利用PID控制算法对系统稳态和动态响应进行了调试，提高了机床实验平台的运行稳定性和可靠性。（3）设计了主动控制“单向进液”电解液流动模式，为了提高加工区域内电解液的输送能力，提出了阴极侧面内缩方案，建立了流固耦合模型，对电解液全流场进行了仿真计算，分析了主动控制电解液流场作用下的阴极受载变形情况，进而对阴极结构进行了优化，实验结果验证了阴极优化的正确性。（4）开展了流场主动控制模式下异形型腔的成形机理研究，建立了不可压缩流场数学模型，基于Fluent动网格技术进行了合理的网格划分，编写了电解液流场边界动网格控制函数，获得了流场内的流速、压力和缺液状态分布情况，初步掌握了三维复杂流场动态变化规律，根据流场变化趋势，建立了动态优化策略，确保了加工过程中电解液流场始终处于均匀、稳定的状态。上述研究成果有助于进一步提高异形型腔整体构件的电解加工精度和质量，为整体构件电解加工技术在航空发动机中的应用奠定了良好的基础。