الفهرس 
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Abstract
In this thesis, a wall condensation model for steam in the presence of non-condensable gas is successfully integrated into ANSYS FLUENT commercial computational fluid dynamics (CFD) software. The condensation process occurring in a single-phase multi-component flow is modeled by adding sink terms to consider the impact of vapor removed from the computational domain on the mass, momentum, energy conservation, as well as turbulence transport. These sink terms are programmed using C language and included within ANSYS FLUENT via its User-Defined Functions (UDFs) capability.
The condensation process is assumed to be driven by the vapor concentration gradient within the mixture, neglecting the thermal resistance of the liquid film. Given the importance of the conditions at the wall, the process is modeled as a conjugate heat transfer problem.
The condensation model is thoroughly validated using experimental data from three different facilities to prove the model’s capability of predicting the condensation rate and associated heat flux. The first two occur under steady-state conditions in a simple one-dimensional geometry, while the last one focuses on transient three-dimensional flow conditions that may occur in the containment of a nuclear power plant in the rare event of a postulated accident.
The first validation test uses data from the CONAN test facility. Five cases with different inlet conditions have been simulated, and the model predictions of condensation rate as well as the wall heat flux are found to be in good agreement with the available experimental data. Moreover, a comparison with a previous numerical study indicates noticeable improvements in the current condensation model.
The second validation is performed using data from the Kuhn test facility, in which the condensation occurs in a vertical tube. The experiments provide temperature measurements along the test sections, runoff test 2.1-8R-Air, whose results were found to be in reasonable agreement with the model predictions.
The model is applied to a large-scale test facility, PANDA, to reflect the model capabilities under the complex flow conditions inherent in a three-dimensional flow domain. Contrary to the previous cases, the PANDA experiments are concerned with the condensation in low Reynolds number flow under transient conditions. The numerical results are discussed and compared with the available test measurements and also found to be in reasonable agreement.