网格融合技术在列车过隧道运动网格数值模拟中的应用

Application of the mesh fusion method in numerical simulation of a high-speed train passing through a tunnel

在高速列车过隧道问题的数值模拟中,为提高模拟准确性而考虑转向架、受电弓导流罩、车厢连接处等细部结构后,几何模型变得复杂。为了得到质量高、适用性强的计算网格,在列车附近生成非结构化四面体网格,运动网格及计算区域其余部分划分块结构化六面体网格。在融合面上,利用网格融合技术处理四面体网格的三角形面网格和六面体网格的四边形面网格的联结问题,通过控制节点位置的变化满足拓扑一致,实现无缝连接。通过三维数值模拟计算结果与一维实验结果的对比发现,在同等精度要求下,采用网格融合技术及分区思想生成的网格整体上数量更少,生成速率更高,该方法可推广应用于更复杂几何模型的网格划分中。

In numerical simulation of turbulent flow around a high-speed train passing through a tunnel,in order to get more physically accurate results,detailed local compositions such as bogies,pantograph cover and windshield have to be considered,thus the model becomes increasingly complicated.The multi-block mesh generation and mesh fusion method are adopted to obtain a computational grid with high quality and applicability.Unstructured tetrahedral meshes are generated around the highspeed train,and structured hexahedral meshes are generated in the moving zone and the rest of solution domain.On the interfaces,the triangular and quadrangular surface meshes of two blocks are fused by controlling the change of node positions,which makes the topology consistent and the grids connected.The subsequent simulation results of the computational grids are compared with those of one dimensional characteristics method,which shows that the presented method can provide less grids points and higher generation rate under the same accuracy requirement.The method can be further used in similar studies.