Numerical investigation on heat transfer characteristics of helium‐xenon gas mixture.

Summary: Helium‐Xenon (He‐Xe) gas mixture featured with low Prandtl number is increasingly used in various energy devices as heat‐carrying agent. To figure out the heat transfer characteristics of He‐Xe gas mixture in uniformly heated circular and tri‐lobe channels, numerical investigations are conducted and presented in the article. The adopted calculation models are validated by comparison between simulation results and experimental data. The local and total heat transfer characteristics are obtained, and new temperature correction factors for the circular and tri‐lobe channels are proposed and recommended. The simulation results obtained by using the SST k − ω turbulent model agree well with the experimental data, this kind of turbulent model matched with appropriate turbulent Prandtl number model could provide satisfactory temperature predictions for He‐Xe gas mixture in a wide range of temperature ratio Tw/Tb. The simplified Petukhov correlation with temperature correction can give conservative predictions with relative error less than 10%. For the tri‐lobe channel, due to the local restricted flow, the gas temperature at the corners is much higher than that at the concavities. The local wall temperature and local Nu number vary azimuthally, showing a large temperature gradient. The tri‐lobe channel has better heat transfer performance than that of the circular tube when the temperature ratio Tw/Tb is no more than 1.5, but it deteriorates significantly with the increasing temperature ratio. This article may contribute to the numerical simulation and thermal design of heat transfer components concerning He‐Xe gas mixture. [ABSTRACT FROM AUTHOR]