Numerical investigation on conjugate heat transfer performance of micro-channel using sphericity based gold and carbon nanoparticles

Numerical study has been carried out on the laminar forced convection ow of nanouids in a wide rectangular micro-channel. The ow and heat transfer characteristics of gold as well as single walled carbon (SWCNT) nanouids are investigated in order to _nd efficient and cost effective heat transfer uid. The effects of nanoparticle volume concentration, spherical and cylindrical particulate sizes on the conjugate heat transfer performance of micro-channel are reported. The effective thermal conductivity of nanouid is evaluated on the basis of particle sphericity by considering the volume and surface area of the nanoparticles. The average convective heat transfer coefficient increases with increase in Reynolds number and volume concentration. Moreover, sphericity based thermal conductivity evaluation showed that increasing the length of SWCNT nanoparticle has signi_cant effect on the heat transfer performance concluding that axial heat conduction dominates the radial heat conduction with in the nanoparticle. The carbon nanouid is identi_ed as an optimized heat transfer uid with better heat transfer characteristics in comparison with gold nanouid. It also reduces the cost of the working uid. The variations in the interface temperature between solid and uid regions are reported for nanouids with different concentrations at different Reynolds numbers. The diameter and length of SWCNT nanoparticle show signi_cant effect on heat transfer characteristics