Performance assessment of longitudinal flow through rod bundle of ETRR-2 Cobalt/Iridium irradiation device.

• Longitudinal flow through rod bundle of ETRR2 Cobalt/Iridium irradiation device was studied. • Study of optimal performance was carried out. • Contours of fluid temperature , fluid velocity, and temperature of Ir rods were illustrated. • Determination of the conditions at which minimum entropy generation was defined. • The present results can be correlated well with best fit correlations. In the present paper, three dimension CFD analysis was presented for longitudinal flow through rod bundle of ETRR2 Cobalt/Iridium irradiation device. Study of optimal performance for both heat transfer and flow characteristics was performed by the determination of the conditions at which minimum entropy generation exist. The study was performed for Reynolds number (Re) in the range 2 × 104 ≤ Re ≤ 5.5 × 105, and Prandtl number (Pr) in the range 3.2 ≤ Pr ≤ 5.2 under both the conditions of uniform and non uniform (cosine shape) heat flux. Contours of fluid temperature and fluid velocity at irradiation box outlet as well as temperature contours of Ir rods at different values of inlet velocity were illustrated. Two correlations one relating the Nusselt number (Nu) with Re and Pr and the other relating skin friction factor with Re was presented in the studied range of Re and Pr. Determination of the applicability of the existing correlations for turbulent forced convection heat transfer and friction coefficient are also presented. Comparison between the flow and heat transfer characteristics through Ir rods of different locations in the irradiation box is presented. [ABSTRACT FROM AUTHOR]