Comparison of film condensation models in presence of non-condensable gases implemented in a CFD Code

Several film condensation models in presence of non-condensable gases are presented. They have been implemented in a CFD code and compared with experimental data. The aim was to improve the code for simulating the gas mixing process in large containment buildings involving steam. The models based on correlation are more robust and simpler, but they work badly out of their experimental conditions. The mechanistic models, based on the diffusion layer theory, work well in numerous conditions but the algorithm are more complicated. Moreover, they run badly when the convective heat transfer is not well predicted by the code.The main material of this paper is part of the PhD Thesis Numerical Models Implemented in a Computational Fluid-dynamics Code for Hydrogen Combustion Risk Assessment within Containments, J.M. Martín-Valdepeñas, Universidad Politécnica de Madrid, 2004.