薄壁大平板铸件的反重力充型数值模拟

Numerical Simulation for Large Thin-walled Plate Castings in Counter-gravity Mould Filling

Sola VOF方法是目前进行铸件充型模拟的主流方法。用VOF方法捕捉自由表面 ,难以施加自由表面条件。采用守恒标量法将气液两相作为同一相来计算 ,从根本上克服了VOF方法所遇到的计算困难。而守恒标量法在处理气 /液界面时存在着两相参数跃迁的难题。针对守恒标量法格式的特点 ,对相应的Simple格式进行了重构 ,从而解决了上述问题。根据以上原理 ,用反重力充填大平板的水力模拟试验作了验证计算 。

At present Sola-Vof is the popular method in simulating mould filling of casting but it is difficult to exert the boundary conditions upon the free surface of liquid by Vof. The above difficulty is overcome at all by calculating the fluid flow field of coupled gas with liquid phase as a single phase N-S equation using conservative scalar method. But in this circumstance there exists the trouble with the numerical divergence caused from large variations across the interface in coping with the interface of gas/liquid. The Simple scheme has to be reconstructed according to Van-leer scheme. The experiments were conducted by hydraulic simulation for filling large plate in counter-gravity mould, and the simulating results agreed well with the experimental results.