Multiphase flow in porous media is a vital process for a wide range of aspects in earth science and for many technical applications. In this regard, heat and mass transfer as well as the phase change by evaporation are of particular interest. The fluid can contain various constituents and can differ in its temperature from the solid phase, with whom it may exchange heat. Furthermore, capillary forces acting on phase interfaces can influence the heat and mass transfer. The current state of research lacks a validated numerical approach of solving the complex mechanisms of multiphase multicomponent flow in porous media and complete phase change of the fluid in terms of the transition from the subcooled to the superheated state. In addition, the consideration of capillary forces and local thermal non-equilibrium impairs the modeling. In this work, these concepts are described in a physical manner, implemented in MATLAB in forms of multiphase mixture models and applied to test cases. The developed numerical code is validated with experimental data which were produced for this work. In particular, the numerical simulation of the evaporation of a single component fluid is conducted with the application of transpiration cooling. The verification is done with data obtained from the literature and an open source model for porous media flow (DuMux) which was developed independently of this work and does not comprise the concept of a multiphase mixture model. In this thesis, it is shown that qualitative accordance is found. The quantitative differences are discussed and put in context with the numerical treatment. Moreover, the sensitivity to parameters is investigated. It was found that the multiphase mixture model for single component 1d flow produces the same velocity and pressure profiles as the DuMux model, if equal temperature profiles are provided for both models. The application of this multiphase mixture solver for single component fluids to 2d flow with evaporation inside of vertical porous channels produces results which have not been described in the literature yet. A parameter variation with dimensionless quantities shows that the results are physically reasonable. The concept of this mixture model is extended to multiple constituents and is discussed in detail with regard to the numerical implementation. The result, the multiphase, multicomponent mixture model is applied to a transpiration cooling test case and shows physically reasonable results. Finally, this work presents experimental data for validation. Firstly, the isothermal mass transport is measured with an experiment and compared with numerical data. Secondly, the evaporation inside a porous medium is experimentally measured for 1d flow. The temperature profiles with varying boundary conditions such as mass flux, heat input and fluid composition conform with the numerical results in a qualitative way. In conclusion, using modeling and simulation methods in conjunction with experimental validation, the numerical description of multiphase and multicomponent flow in porous media was explored. This contribution can be applied readily using the introduced mixture model and is modular with regard to the introduction of additional physical effects.    «

Multiphase flow in porous media is a vital process for a wide range of aspects in earth science and for many technical applications. In this regard, heat and mass transfer as well as the phase change by evaporation are of particular interest. The fluid can contain various constituents and can differ in its temperature from the solid phase, with whom it may exchange heat. Furthermore, capillary forces acting on phase interfaces can influence the heat and mass transfer. The current state of resear...    »