performance study of partially heated annulus filled with two-phase nanofluid: energy perspective

In recent years, electrical appliances have become an integral part of human life, and efforts have been made to improve the quality and durability of electrical boards. one of the ways to improve the life of electrical boards is using cooling methods suitable for transferring the heat generated by the boards. in this paper, three different models of case 1, case 2, and case 3 have been analyzed to provide an optimal model with the highest average nusselt number. to achieve the optimal model the effect of heat source, the characteristics of hot and cold barriers and their locations on the flow field, heat transfer between two horizontal concentric cylinders with the presence of nanofluids were investigated. the results have shown that for all volume fractions, the nusselt number increases with rising riley number, as well as for the inner and outer cylinder, the value of the average nusselt number increases at a constant riley number with rising the volume fraction from 0 to 0.8%. therefore, the highest nusselt number occurs in volume fraction of 0.8% and riley number of 10^5.