Experimental investigation on flow and heat transfer characteristics of He-Xe gas mixture.

• Flow and heat transfer experiments of He-Xe gas mixture is conducted. • Friction factors and Nu numbers for 4000< Re <3 × 104 are obtained. • Empirical correlations are compared and recommended. The helium gas mixed with xenon gas is increasingly adopted as the working fluid for closed gas turbine cycles to optimize power/weight ratio and system efficiency. The flow and heat transfer performance of the He-Xe gas mixture has received widespread attention. In this paper, the closed gas loop with vertical circular test section is built, and the convective heat transfer characteristics of He-Xe gas mixture is experimentally investigated during the Reynolds number range of 4000–3 × 104. The wall temperature and gas pressure are measured, and the correlations of Nusselt number and friction factor versus Reynolds number are obtained. The main findings are as follows: the overall average friction factor can be predicted by the Blasius correlation and Taylor's friction correlation; the local Nusselt number agrees well with the Pickett correlation for Re >8 × 103; new correlations are proposed to predict total Nusselt number for 104 < Re <3 × 104 and 4000< Re <104, respectively. This study may contribute to the thermal design and optimization of heat exchangers concerning He-Xe gas mixture. [ABSTRACT FROM AUTHOR]