Entropy Generation Minimization of Confined Nanofluids Laminar Flow Around a Block

According to the importance of cooling and heating process of a solid object, entropy generation in confined flow around a block is studied. In the current study, numerical simulation of laminar flow and heat transfer of nanofluids with nanoparticles of different shapes is considered. The nanofluids are water mixture with either Al2O3 nanoshperes or carbon nanotubes (CNTs). The incompressible Navier-Stokes and energy equations are solved numerically in a body fitted coordinates system using a control volume technique. The flow patterns and temperature fields for different values of the particles concentrations are examined in detail. Furthermore, the effects of nanoparticles shape and concentration on the heat transfer are studied. Furthermore the influences of nanofluids on pressure drop and pump power is examined. On the other hand, the entropy generation minimization is considered as the optimization criterion. The results indicate that in most cases the nanofluids enhance the heat transfer as well as pressure drop. It is interesting to note that the shape of nanoparticles is critical in determining the key mechanism of heat transport in nanofluids. Nanofluids with cylindrical nanoparticles exhibit a greater increase in heat transfer compared with nanofluids having spherical shape nanoparticles.