Abstract: Numerical investigation into convective heat transfer of CuO-Water based nanofluid in a pipe with return bend under laminar flow conditions has been done. The impacts of Reynolds number and the volume concentration of nanoparticles on the flow and the convective heat transfer behaviour are investigated. The results indicate that the increase in Reynolds number leads to the enhancement of average Nusselt number, and the increase in specific heat in the presence of the nanofluid results in improvement in heat transfer. Also, the presence of the secondary flow in the curve plays a key role in increasing the average Nusselt number and it appears higher than the inlet and outlet tubes. However, the pressure drop curve increases significantly in the tubes with the increase in nanoparticles concentration.
Abstract: The new design of heat exchangers utilizing an
annular distributor opens a new gateway for realizing higher energy
optimization. To realize this goal, graphene nanoplatelet-based water
nanofluids with promising thermophysical properties were
synthesized in the presence of covalent and noncovalent
functionalization. Thermal conductivity, density, viscosity and
specific heat capacity were investigated and employed as a raw data
for ANSYS-Fluent to be used in two-phase approach. After
validation of obtained results by analytical equations, two special
parameters of convective heat transfer coefficient and pressure drop
were investigated. The study followed by studying other heat transfer
parameters of annular pass in the presence of graphene nanopletelesbased
water nanofluids at different weight concentrations, input
powers and temperatures. As a result, heat transfer performance and
friction loss are predicted for both synthesized nanofluids.