混流式水轮机转轮焊接过程数值模拟的特殊性分析

Particularity analysis of Francis turbine runner’s simulation during welding

针对混流式水轮机转轮焊接过程数值模拟的特殊性,提出了利用点点连接解决焊接热源的加载问题的方法以及利用将焊缝分成若干区域而逐步杀死单元的技术解决焊缝填丝过程的方法,同时利用转轮的焊接温度场证明了上述方法的正确性与合理性。另外,接触体的使用成功地解决了各独立实体间接触边界节点不重合的热传导问题以及具有复杂表面的叶片与空气之间的散热问题。这对具有复杂结构焊件的数值模拟有着重要的指导意义。

Aiming at the particularity of Francis turbine runner's simulation in the process of welding, the method was adopted which solved the loading of welding thermal source by means of node-to-node connection and the method was brought forward which solved the problem of weld's wire feed by dividing the weld into many parts. These two methods were proved reasonably by the runner's temperature field. Moreover, the problem of heat conduction between independent entities and the problem of heat elimination between blade and air were successfully solved by using contact bodies. It had important guiding significance to the numerical simulation of complicated weldments.