网格划分对铸嘴型腔流场有限元分析的影响

Influence of mesh types in two-dimensional FEA analysis of the cavity fluid field of nozzle cavity

采用四边形自由网格和四边形映射网格2种不同网格划分方法,分别对一种小型双辊铝铸轧机上的铸嘴型腔的内部流场进行了2维有限元建模和计算分析,并对这2种不同网格划分模型的计算结果进行比较,从对称性、收敛性和计算过程误差分析3个方面,证明映射网格方法是一种具有较高精度的网格划分方法,并从理论上对2种方法存在的结果差异进行简要分析。在流体有限元分析中,采用映射网格不仅有助于减少由于网格划分带来的计算误差,还能防止运算发散,有利于获得更精确的结果。当模型比较复杂,几何形状很不规则,无法在模型中全部采用映射网格划分时,要多使用映射网格,少用自由网格,以减少由于网格划分带来的有限元分析的误差。

Using methods of free mesh and mapped mesh of quadrangle, the fluid field of 2 dimensions of nozzle cavity of a small-scale twin roll casting strip of aluminium is analysed. The results of the two kinds of mesh are compared in the aspects of symmetry, convergence and errors, and the conclusion is that the mapped mesh method is more accurate than the free mesh method. The diversity of the results of the two methods is demonstrated briefly in theory. In the analysis of fluid FEA, mapped mesh method is helpful to reduce the calculating error, avoid divergence and obtain more accurate results. Even if the models are complex, the mapped mesh method can be applied as much as possible.