Meshing issues in the numerical solution of the tunnel inflow problem

摘要

The paper deals with the groundwater flow numerical simulation in this paper. In particular, the problem of water inflow into a tunnel is solved, with emphasis on the effect of geometry and mesh resolution. Models with different tunnel sizes and various mesh resolutions are compared in 2D and a correction factor of the coarse tunnel representation derived for a subsequent use in the 3D model comparison. In the 3D variants, a former model with coarse tunnel shape and the correction factor is compared with a new model with finer resolution. The improvement of the preprocessing procedure is in evaluation of the tunnel and planar model features intersections. The models fit well between each other except the middle layer with transition between different materials, when the shape of the material divide cannot be well represented in the coarse model. This work follows previous modeling studies of field data interpretation and gives justification to the former results and more accurate options for the future evaluation.