Development of the fast structured mesh generation tool and its application in metallurgical simulation

Abstract

A structured grid enables higher computational fidelity and better convergence in the calculation of high-precision complex simulation problems, particularly for high-speed flow field or multiphase flow. However, its generation is usually difficult, labor-intensive, and time-consuming; thus, how to quickly generate a quality structured grid is a frontier topic in various simulation scenarios, such as computational fluid dynamics (CFD). Metallurgical vessels need to be served at high temperatures, and their inner cavity are filled with refractory materials. The structure is usually relatively regular. According to the geometric structural characteristics of metallurgical vessels, parametric modeling and mesh generation have been adopted to successfully develop a fast mesh generation tool suitable for metallurgical reactors by taking advantage of batch data processing of Python Script and open-source CFD software OpenFOAM. Following the analysis of the internal topological logical relationship of the target geometry structure, it was divided into several basic geometric units, such as torus, cones, and quadrilateral columns, and their geometric parameters and topological parameters were obtained. The shape and spatial position of the basic geometric structure were determined by its geometric control parameters. The code was written according to the topological relation of the target geometry structure, and the structured grid of basic geometry units was gradually stacked into the target geometry structure. Thousands of coordinate information can be output and sorted using Python Script according to the predetermined logic in a short time. After script execution, a dictionary file called blockMeshDict required by blockMesh can be generated and then converted into a .msh file. With ladle, tundish, mold, and its auxiliary connecting device as examples, a mesh-generation tool is developed and examined. Consequently, the generated grid had high quality considering its checking distortion and orthogonality, which can meet the needs of various simulations. This tool exhibits remarkable advantages over traditional pretreatment methods in solving the geometric structure update and mesh adjustment of metallurgical vessels (e.g., changing the position of the retaining wall in tundish and the position of the bottom blowing plugs in the ladle) and can quickly generate high-quality structured meshes in several or tens of seconds. A user-friendly graphical user interface was also developed, which only needed key geometric structure and mesh parameters, and the corresponding structured mesh can be generated conveniently. The program is continuously being optimized to provide more visual and interactive performance. It can effectively improve the simplicity and efficiency of preprocessing. This tool is expected to be applied to digitalization and intelligent transformation for the metallurgical industry and provide effective support in industrial software.

Keywords

• structured mesh
• parameterization
• simulation
• tool software
• digitalization and intelligence