In ProCAST, tetrahedral mesh model is commonly used for mesh generation. The quality of mesh usually affects the accuracy of final equation solution and simulation analysis. Firstly, the vermicular cast iron pressure plate and the designed gating system model are assembled and inspected in UG software, and then the assembly is imported into the visual mesh module of ProCAST to inspect and repair the surface connectivity, overlap, and intersection splitting of the entire vermicular cast iron pressure plate assembly, and then the division, inspection, and repair of the surface mesh of the vermicular cast iron pressure plate model are started, Repair small angles, sharp corners and other damaged triangular meshes; Regenerate the adult mesh after repair. Finally, examine and refine the volume mesh to see if it contains invalid and negative Jacobi elements. If such elements are included, you need to re partition or optimize the partition rules until the above elements are not included.
The mesh generation method adopts the free mesh generation method, and reduces the number of meshes as much as possible without affecting the accuracy. Here, the grid size of vermicular cast iron pressure plate and gating system is set to 3mm, and the division results show that the number of surface grids is 157390, the number of volume grids is 3225544, and the number of nodes is 569502, as shown in the figure.
The relevant parameters set for numerical simulation of vermicular cast iron pressure plate model are shown in the table.
| Castings | GGV30 vermicular cast iron |
| Sand mold | Resin sand |
| Interface heat transfer coefficient / (w · m-2k-1) | 500 |
| Pouring temperature / ℃ | 1419 |
| Pouring time /s | 7.5 |
| Pouring method | Gravity pouring |
| Cooling mode | Natural air cooling |
| Sand mold temperature / ℃ | 25 |
| Gravity parameter direction | Negative y |
| Acceleration / (m · S-2) | 9.8 |
| Number of operation steps | 50000 |
| Stop condition temperature / ℃ | ＜500 |