发动机叶片电解加工等入流角流场设计与试验研究

在大扭角、长叶身型复杂曲面叶片电解加工中,通常采用传统纵向侧流式流场加工,电解液在叶尖至叶根的入流角度差异较大,电解液分流不均,易引发短路等加工意外。提出了一种等入流角流场,即在理论模型上由叶尖至叶根截取若干截面,在截面中以进排气边缘两侧切线的角平分线方向为入流方向,将各流道沿各自的入流方向延伸形成等入流角流场。该方法均匀了电解液入流角,有利于提升流场稳定性。利用有限元方法对等入流角与纵向侧流式流场进行了对比,结果表明等入流角流场可有效提升流场的均匀稳定。进行了等入流角流场的加工试验,结果表明该流场可获得较好的加工稳定性与加工质量。

Design and Experimental Investigation on Flow Field with Equivalent Inflow Angles in ECM of Turbine Blades

In conventional design method,the flow fields are always extended along a certain direction. When electrochemical machining (ECM) of complex curved blades with big twist angles , significant differences of inflow angle will affect the stability of the flow field. It is likely to cause short circuit in ECM. In order to improve the stability of the flow field ,a new design method of flow field was proposed to ECM turbine blade. In this method ,the directions of flow field extending were designed as angular bisectors of leading edges tangents. All the inflow angles were designed to be equal. The new flow field was analyzed by finite element method. The result showed that new flow field was more stable than conventional flow field during the ECM. In order to prove the rationality of new flow field ,the experimental investigations were carried out. The results showed that the ECM machining stability and surface quality of blade were improved by using the new flow field.