CFD simulations in the nuclear containment using the DES turbulence models

•The k-ɛ based DES model is used in the nuclear containment simulation.•The comparison of results between different turbulent models is obtained.•The superiority of DES models is analyzed.•The computational efficiency with the DES turbulence models is explained. Different species of gases would be released into the containment and cause unpredicted disasters during the nuclear severe accidents. It is important to accurately predict the transportation and stratification phenomena of these gas mixtures. CFD simulations of these thermal hydraulic issues in nuclear containment are investigated in this paper. The main work is to study the influence of turbulence model on the calculation of gas transportation and heat transfer. The k-ɛ based DES and other frequently used turbulence models are used in the steam and helium release simulation in THAI series experiment. This paper will show the superiority of the DES turbulence model in terms of computational efficiency and accuracy with the experimental results, and analyze the necessities of DES model to simulate the large-scale containment flows with both laminar and turbulence regions.