Simulation of Hydrogen Combustion Experiment in Large-Scale Experimental Facility with ANSYS Fluent CFD Code

Hydrogen combustion following a postulated severe accident can jeopardize the structural integrity of a Nuclear Power Plant's (NPP) containment. Computational Fluid Dynamics (CFD) modelling approach can be used to conduct a risk assessment of such an event. This paper presents the first CFD simulations based on the results from large-scale HYKA UFPE experiment, with the total volume of the experimental vessel measuring 220 m(3). The applied CFD modelling approach uses Flame Speed Closure combustion model implemented in the ANSYS Fluent code. The results include grid independency as well as turbulence model sensitivity analyses. The paper also underlines the importance of using the complete heat transfer mechanism, including convection and thermal radiation, as a boundary condition. Both qualitative and quantitative assessments of the obtained results are presented and compared to the experimental results.