鋳造伝熱解析の鋳型領域に対する簡便なボクセル要素数削減方法

抄録

  In the present study, a method was proposed for automatically combining elements in the mold region to reduce the number of elements of mesh data divided into voxel meshes. Three types of evaluation methods for heat flux at the interface between fine and coarse elements were evaluated based on the strict solution of one-dimensional unsteady heat conduction. Solidification analyses simulating die casting of an oil pan were carried out to verify the reduction in the number of elements and calculation time. As a result, the following findings were obtained. A method for estimating the temperature of virtual fine elements inside a coarse element was proposed by considering both spatial distribution and conservation low. As for the evaluation method for heat flux at the interface between fine and coarse elements, the method using the estimated temperature of virtual fine elements within a coarse element was found to be the most accurate in the tested three methods. By defining appropriately sized merging-prohibited regions around casting and cooling elements and combining mold elements in other regions, the number of elements was significantly reduced with accuracy remaining nearly unchanged. For the case study simulating die casting of oil pan, the reduction ratio of number of elements was up to 93.3% and that of time for solidification analysis was up to 84.2%.