Flow and heat transfer characteristics of a nanofluid as the coolant in a typical MTR core

Abstract

Abstract The purpose of this work was to perform a thermal–hydraulic numerical analysis of a nanofluid as the coolant in a typical MTR (material testing reactor) core. Numerical simulation was carried out for turbulent flow of water based nanofluid of different concentrations of Al2O3 nanoparticles through a sub-channel of a typical MTR core subjected to cosine shape heat flux at various values of Reynolds number using the Ansys-Fluent computer code. The optimum performance of the studied nanofluid as a coolant in MTR core was determined by the determination of the conditions under which the total entropy generation due to both heat transfer and fluid flow had a minimum value. The results showed that this condition was at Re = 4.8 × 104. The studied range of Reynolds number (Re) and particle concentration (ϕ) were 2.5 × 104 ≤ Re ≤ 5.6 × 104 and 0% ≤ ϕ ≤ 9% respectively. Results for local and average heat transfer and flow characteristics were presented. For the studied range of Reynolds number and particle concentration, four new correlations were developed. Two correlations relating Nusselt number and friction coefficient with the parameters Re and ϕ whereas the other two correlations were one relating Nusselt number with Reynolds and Prandtl numbers and the other relating the friction coefficient with Reynolds number.