基于不规则网格模型的充型及凝固过程数值模似

Numerical Simulation in Mold Filling and Solidification Process Based on Irregular Meshing Model

采用直接差分法建立了液态金属充型过程模拟计算的数值模型。该模型对采用不规则单元剖分的网格模型进行充型及传热模拟计算具有广泛的适用性，能较好地处理具有复杂形状的铸件充型过程模拟。采用过流单元流量分配方法处理充型过程自由表面单元，并考虑了表面单元液态金属部分充填对传热计算的影响。对计算过程中速度和压力的修正、自由表面单元压力的计算及过流单元流量分配等进行了研究，应用上述模型开发了三维模拟计算程序，并成功地应用于薄壁铸件的充型过程模拟。

Abstract Numerical model was derived for simulating mold filling process of liquid metal by using direct finite difference method,which is extensively suitable for simulating calculation of mold filling and heat transfer of liquid metal using the irregular element meshing model,so the simulation method is best applicable to mold filling of the complicated shape castings.The paper treats free surface element of mold filling process employing overflow element redistribution technique and considering effect of the liquid metal part filling in free surface element on the calculation of heat transfer.The revision of velocity and pressure,calculation of pressure in free surface element and the distribution of fluid in overflowing elements were investigated,based on the above mentioned model,the 3 D computer code has been developed,which are used on the thin walled casting successfully.