This dissertation focuses on the modeling of two-phase flow processes including the water and gas phase in porous media with fault zones which consist of fractures or macropores. The aim of the thesis is to make applications and comparisons of different model concepts in order to improve the process understanding and to reveal possibilities and limitations of the different approaches as well as to provide knowledge related to the potential for investigations of two-phase flow modeling in porous media with fault zones. Here, three different model concepts were investigated: 2D fracture model concept, 1D fracture model concept and fracture with pipe model concept. Generally, the choice of model concept is strongly depending on the characteristics of the problems being considered, for example, the scales of the problem. The modeling of two-phase flow processes in porous media with fault zones has been applied to domains with different scales (small scale (weiterlesen